Journal of Medical Physics
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   1986| July-December  | Volume 11 | Issue 3  
    Online since April 24, 2009

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Experiences In The Use Of Microtrons For Radiation Therapy
Rune Walstam
July-December 1986, 11(3):1-3
The potential advantages of the MICROTRON as an electron accelerator for radiation therapy can be summarized as follows: 1. Dual photon energies can easily be obtained. 2. A favourable range of electron energies are available. 3. The beam current - and thus also the output - is high. 4. The electron energy spectrum is extremely narrow - thus offering: a. optimization of electron and photon beam properties b. a separate room with a stationary accelerator and a favourable gantry design c. electron transport through vacuum tubes to more than one irradiation facility. Medical microtrons have been in use since more than 10 years and a continuous improvement of design and energy range has taken place. The reasons for requesting higher energies are illustrated by means of treatment plans. The optimal photon energy for various treatment techniques will be discussed as well as the importance of the design of the target, the beam flattening filters, scattering foils and the collimator. Recent developments of a multileaf collimator will be presented as well as the expected advantages of such a system for some clinical applications. The layout of some special microtron therapy departments will be presented as well as performance data, reliability and maintenance requirements as experienced on some of the installations. A fairly detailed study of the neutron flux measured at some therapy installations will also be presented. The level of fast and thermal neutrons and their possible clinical significance will be discussed. In conclusion a process of improving the properties of external beam equipment - amongst them the medical microtrons - is still going on and this will hopefully further improve the survival and reduce the complication rate for patients treated with such modalities.
[ABSTRACT]   Full text not available  [PDF]
  731 44 -
Status Of Medical Physics In India
A Bose
July-December 1986, 11(3):418-418
The Medical physics activities originated in India as in other places around the world in the Departments of Radiation Therapy. Subsequently the activities spilled over to the Departments of Radio-diagnosis and Nuclear Medicine. The first Medical physicist in India was Dr. Naidu who was trained in France. He joined the Tata Memorial Hospital, Bombay in 1938. Subsequently Dr.N.N Dasgupta joined him in 1940 and was there till 1942. Medical physics Departments were also established in the Bernard Institute of Radiology, Madras and the Chittaranjan Cancer Hospital, Calcutta where Dr. Dasgupta worked as consultant. In 1950, The Chittaranjan Cancer Hospital boasted of a million volt X-ray unit. There were not many around the world at that time and it was the first of its king in Asia. The best thing that could happen to Medical Physics in India was the establishment of the Directorate of Radiological Protection in the then Atomic Energy Establishment, Trombay. With the painstaking and untiring efforts of this Directorate subsequently renamed the Division of Radiological protection the Medical physics in India has found a place of pride in the global Medical Physics activity. On the basis of population, cancer incidence and suitability of treatment by radiation it has been estimated that right now the country needs more than, 500 Medical physicists, this demand will Being aware of this demand, the Bhabha Atomic Research Centre in collaboration with the University of Bombay is conducting a one-year course for training in Medical physics since early sixties, Anna University, Madras has a 3 years course of MSc in Medical Physics, career opportunities are not uniform and some trained Medical physicists are also lost to the Industry. It is suggested that Universities should incorporate Medical Physics in the postgraduate Biophysics courses in collaboration with established Medical physics Centres to bridge the gap.
[ABSTRACT]   Full text not available  [PDF]
  640 55 -
Selectron - HDR Intracavitary Therapy In Carcinoma Cervix Uteri - A Preliminary Experience
S C Sharma, B D Gupta, F D Patel, A P S Sandhu, P S Negi
July-December 1986, 11(3):184-184
Since January 1985, a Selectron - HDR (High Dose Rate), 3 channels Machine with Sources 480 mCi. Each has been used in our department for intracavitary treatment of carcinoma cervix uteri. 100 patients of various stages of carcinoma cervix have been treated since January to December 1985, on this machine. After initial workup, all patients were initially treated with whole pelvic external radiation with Cobalt 60 beam, delivery a dose of 4500 rads in 20 fractions in 4 weeks. After a rest period of 3 - 4 weeks, the intracavitary was given on Selectron - HDR. Two fractions of 850-900 rads at point 'A' were given with a gap of 7 days between each fraction. The aoolication was done under general anesthesia and then AP and latral pelvic films were taken for localization and computer calculation of dose before treatment in each patient. The dose at different points in rectum and bladder was correlated with the dose at point 'A' This preliminary experience will communicate the local control of the disease, pattern of failures and early radiation reactions in this group of patients who have follow up varying from minimum of 6 months to maximum of 18 months. The results obtained will be compared with patients treated with conventional low dose rate intracavitary therapy during the same period.
[ABSTRACT]   Full text not available  [PDF]
  547 57 -
An Analytical Equation For Brachy Therapy Dosimetric Calculation
U B Tripathi
July-December 1986, 11(3):167-167
Linear sources with various sheathing thicknesses are used under different geometrical configurations in interstitial and intracavitary brachytherapy. Dose computation at a point from these line sources involve the evaluation of Sievert's integral which can only solved numerically. This paper describes a method for analytical solution of the Sievert's integral, I (θ). This analytical expression has the form: I (θ) = θ + A In (Sec θ + tan θ ) + B tan θ … (1) where is the angle (in radians) subtended by the source at the point A depends on of the sheath and B depends on the and angle. Equ (1) together with the coordinates of the source ends (as obtained from the appropriate radiographs) and point of interest helps in computation of dose to any point in any plane. Different orientation of radio nuclides in the patients are automatically taken into account by this procedure. Equ (1) and numerical solution of Sievert's integral agree better than +0.5% for all d values up to 0.25 and for all angles up to 86. For d > 0.2 and 86< 88, the difference is less than 2%. Since Sievert's integral is not valid as, hence I values for cannot readily be compared. Equ (1) is thus, a reasonable analytical representation for Sievert's integral.
[ABSTRACT]   Full text not available  [PDF]
  513 58 -
Entrance Air Kerma Rates In Fluoroscopy And ALARA
S.D Al-Zenki, Leelamma Abraham, Ayad Abdul Wadood
July-December 1986, 11(3):488-488
ICRP recommends an entrance air kerma rate as low as practicable not exceeding 50 mGY/min. for diagnostic fluoroscopy units. Where automatic exposure (brightness) control or a separate higher exposure rate selection is available, a maximum limit upto 100 mGY/min. is accepted in certain countries; eg. united states. Though the above limits may be accepted for compliance testing of equipments, adherence to ALARA need to be ensured in actual use. This paper presents the results of entrance air kerma rate measurements carried out on existing fluoroscopy units in Kuwait to survey the situation. The measurements were made atlicm above table top for under couch tubes, 30 cm. above table top for over couch tubes and 30 cm. away from image intensifier input surface for C-arm units for maximum possible and for normally used technical parameters. Appropriate measurements were made on both manual and automatic mode using an ion chamber type dosimeter. The results indicated that entrance air kerma rate and hence patient dose could be quite often higher by 2 to 8 times than what was adequate to five a good acceptable diagnostic image and in rare cases the possible maximum rates exceeded the regulatory limit by 2 to 3 times. Urgent adjustments were carried out in all such cases and reinspections arranged. Since individual patient dose records are not practicable in diagnostic radiology, the need to have regular equipment performance checks, quality assurance checks, and preventive maintenance and or to incorporate lower regulatory limits (eg. not exceeding 20 mGY/min. as in Nordic countries) was evident as a result of the measurements. The limitation of occupational dose records without medical exposure records in interpretation of subsequent radiation effects for radiation workers or stochastic effects in general population is also obvious.
[ABSTRACT]   Full text not available  [PDF]
  524 43 -
Heating Techniques For Microwave Hyperthermia Treatment Of Cancer
Yoshio Nikawa, Fumiaki Okada
July-December 1986, 11(3):394-394
Hyperthermia has been shown t o be effective in treatment of cancer, especially when combined with chemo-or radiotherapy. It is currently receiving increased attention from oncologists, biologists, engineers, needless to say from clinicians. There are several methods currently in use for producing localized hyperthermia in cancer patients. To use electromagnetic (EM) energy is one of the best means to produce localize d heating i n the human body. In the low frequency region of the EM wave (below several ten megahertz), inductive or capacitive heating is usually used. In this frequency region, the, size of the heating equipment as well as the applicator is too large and the wavelength in the human body is relatively long, therefore the are a of the heating is regional, thus it can not be localized. As compared with this low frequency heating technique, using high frequency region (over several hundred megahertz) is promising for hyperthermia because the wavelength is moderate and the heating equipment and that of the applicator can be made small in size. This technique, known as microwave hyperthermia, heating may be very effective, and the heating area can be localized. Nevertheless, the depth of the heating is always shallow. In this presentation, recent microwave heating techniques for hyperthermia are surveyed, and array techniques to heat deeply in the human body at microwave region is discussed. The discussion is made about a multi - applicator system and an integrated array applicator system. Using the multi - applicator system, deep heating can be realized and the heating portion can be controlled, nevertheless the setup of the applicator to heat human body is rather difficult. On the other hand, using the integrated array applicator, which is designed by means of lens technique, attachment to the human body is easy, because the applicator is single structure. This applicator can converge the field 'of electromagnetic wave deeply inside the human body. The comparison of the heating pattern is made for the integrated wave-guide array applicator and the usually used wave-guide applicator, which has the same aperture size. The discussion is also made about the changing heating pattern technique for microwave hyperthermia.
[ABSTRACT]   Full text not available  [PDF]
  488 65 -
Depth Dose Measurements Using TL Dosemeters For Cobalt 60 And Megavoltage Photon Beams
V K Nelson, K L Popli, R K Kher
July-December 1986, 11(3):147-147
This paper presents the suitability study of two thermo luminescence (TL) dosemeter systems for the measurement of central axis depth dose of Cobalt-60 and Mega voltage photon beams. The two TL systems used are IdF (TLD-100) chips and CaSO4 : Dy phosphor embedded PTFE discs. As the CaSO4 : Dy PTFE discs are locally made; the effect of energy dependence of these discs to high energy photons was also studied. The results obtained by these two systems viz TLD-100 and Caso4 : Dy were found to be reproducible and within + 1.5% and 1.3% respectively for Cobalt 60 energy and for 10 NV X-ray. The results were found to be within 4% when compared with BJR (supplement 11) values. This paper also includes the study of repeated use of CaSO4 : Dy PTFE disc for 10 cycles of reuse when exposed to the doses of the order of 200 R as is usually the case for such measurements. Table 1 presents the relative values of two TL systems compared to BJR values at a few depths in the phantom. Table - 1 C. A. D. D. values for 10x10 cm2 field size and 60 cm SSD for photon beams These results will be further discussed in detail during the presentation.
[ABSTRACT]   Full text not available  [PDF]
  484 54 -
Procedure For Absorbed Dose Calibration And Use Of BARC Make Secondary Standard Dosemeter As Per The Recent IAEA Code Of Practice
A Kannan, S B Naik
July-December 1986, 11(3):146-146
The new code of practice by IAEA for absorbed dose measurement for photon and electron beams recommends the usage of perturbation factor calculated from proximal wall effect factors for the chamber and appropriate (S/P) water/air and (Men/P) water air values instead of earlier recommended C & CE values by ICRU. This paper describes the calibration procedure adopted at Radiological Standards Laboratory for BARC Make SSD's (Tufnol Walled). Calculated factors are given to help the Physicists to adopt the new IAEA Code of Practice. To determine absorbed dose (Dw) in water at specified depth, the required quantities are: (i) ND : Absorbed dose to air calibration factor, (usually specified at Co-60); and (ii) Pu : The factor to allow for non-water equivalence of the ion chamber, when in the user's beam. Evaluation of Pu depends upon the fraction (α) of ionisation due to electrons from the chamber wall and stopping power ration (S/p) water air for the photon energy under consideration. The paper describes the air method of determining (α) and subsequently Pu. For tufnol walled (tuf) BARC chamber, Pu's will be determined at RSL for each chamber at Co-60 since no (S/P) tuf (men/p) tuf air are recommended by IAEA code of Practice. At higher energies (other than Co60) tufnol chamber factors have been evaluated empirically using available data. These calculated values of Pu for tufnol chamber have been used to evaluate Dw at Co-60 and at other photon energies. In order to establish the validity of these empirically calculated factors, the measurement of Dw were carried out by a calibrated graphite chamber for which IAEA recommended values are used and compared with measurement with tufnol walled chamber.
[ABSTRACT]   Full text not available  [PDF]
  468 44 -
Production Of Radionuclides For Medical Diagnosis And Therapy
Garimella V S Rayudu
July-December 1986, 11(3):270-270
Naturally occurring, nuclear reactor produced, cyclotron produce I and generator produced radionuclides were reviewed in Figure 1 with special reference to nuclear medical and biological use. General methods of labeling, and 99mTc, 131I, 125I, 11C, 13N, 15O, 3H, and 14C labeling methods were listed. In addition, nuclear parameters and mode of administration of radionuclides for therapy: 32P, 35S, 60Co, 89Sr, 90Sr+90Y, 90Y, 125I, 131I, 137Cs, 192Ir, 198Au, 211At, 226Ra and the generator produced 212Bi are discussed.
[ABSTRACT]   Full text not available  [PDF]
  459 50 -
A General Formulation For Depth Dose Computation In Photon Beam Dosimetry
H B Tripathi
July-December 1986, 11(3):12-12
This paper describes a generalised formulation for calculation of depth dose distribution at any point in the irradiated medium. Primary (P) and Scattered (S) components of the total dose is calculated at the required point using the following equations: Where is the dose to small of the tissue just large enough to provide electronic equilibrium and located at (f + dm) in free space, is the linear attenuation coefficient for the incident beam energy in water medium, d is depth of the point of calculation along the central axis, dm is the depth of maximum ionisation, f is the source to surface distance, Sm is the scatter part of peak scatter factor. de defines the effective height of the cylindrical volume contributing scattered dose to the axial point. This cylindrical volume is bounded by the beam area at dm. Off-axis dose computation is done with the help of off-axis dose computation is done with the help of off-axis ratio (OAR). OAR is a function of machine and beam area at dm. Off-axis dose computation is done with the help of off-axis ratio (OAR). OAR is a function of machine and beam parameters and is evaluated from the measured transverse beam profiles at 5, 10 and 15 cm computations. These simple relations have been used to generate treatment planning soft wares for Co-60 and Nagavoltage X-rays beam therapy. These softwares can be incorporated into any small computer for computations of complete dose distributions in different planes. Beam weighting factors, wedge filters, body curvature, oblique beam incidence and body heterogeneities are taken into calculations, wherever applicable, before contributions from each beams are summated to yield total dose at the point of interest. Details of the various steps involved and results obtained will be presented during this presentation.
[ABSTRACT]   Full text not available  [PDF]
  449 59 -
Radio Frequency Magnetic Induction Hyperthermia
G Banci, L Begnozzi, C Franconi, L Raganella
July-December 1986, 11(3):395-395
For heating deep seated tumors, many attempts have been made to optimize the development of RF applicators of frequencies low enough to obtain a better penetration, while trying to confine the controlled volume into limited sizes. Magnetic induction applicators have high application potential due to their non invasiveness, to the little skin overheating espected and to the practicality of the electromagnetic coupling with the body. We have developed a class of 27 MHZ magnetic induction applicators (1,2) consisting of two single magnetic dipoles forming a loosely coupled pair (Twin-Dipole) fed by low-frequency, in-phase currents, giving defined heated volumes at intermediate depths due to the effect of phase coherence of both superimposing fields. The results show a penetration depth up to 7 cm and a power deposition pattern exhibiting a well defined maximum which may undergo a controlled shift of a few cm in depth. Moreover, the surface overheating is easily controlled. Low frequency RF inductive applicators produce current loops in the body, and their power deposition pattern depends strongly on the body dimensions and symmetry and on the body-applicator configuration. With the aim of controlling the penetration depth of the Twin Dipoles e have designed and tested a variety of versatile multiple applicator systems employing both active and passive RF auxiliary circuits (3). These systems exploit the coherence effect of the superimposing fields on the controlled volume, in analogy with the phased array technique (4) The results show a significant improvement over single applicators. (1) C. A. Tiberio, L. Raganella and C. Franconi, "symmetric pure induction 27 MHZ applicator", in proc, 2nd Int. 1 Conf, Applications of physics to Medicine & Biol., C. Franconi et al. (Eds), P. 585, World science publ., 1984. (2) L. Raganella, C. Franconi, C.A. Tiberio and 1. Begnozzi, :Linear induction applicator", presented at the 1984 Int.1 symp. (iV) on Hyperthermic oncology, Aahrus, DK, July 2-6, 1984. (3) L. Raganella, C. Franconi, C.A.Tiberio and L. Begnozzi, "RF Induction Applicators III-Twin Dipole with auxiliary circuits", proc. VII ESHO Meeting, Paris, 1985. (4) C. Franconi, C.A.Tiberio, D.Raganella, and L. Begnozzi, "Low-Frequency RF Twin-Dipole Applicator for Intermediate Depth Hyperthermia", in IEEE Trans. MTT vol, 33, Issue on phased Arrays for Hyperthermia treatment of cancer, 1986, in press.
[ABSTRACT]   Full text not available  [PDF]
  478 30 -
Primary Radiation Therapy For Early Breast Cancer : Treatment Planning And Dosimetric Verification with Measurements In Breast Phantom.
S M Deore, B C Goswami, S K Shrivastava, D D Deshpande, M P Saple, R Pandhi, K A Dinshaw, S J Supe
July-December 1986, 11(3):94-94
The treatment of breast cancer presents a highly complex structure, as the target volume is defined by breast itself, the lymph drainage sites to internal mammary chain, the aupraclavicular fosse and the axilla. This target volume in the presence of adjacent structures as the lung and opposite breast presents challenging problems to treatment planning. This article elaborates the treatment technique being used at our centre for the last 4 years. The target volume is typically treated with opposed tangential fields using wedge pair with 6 MeV Linear Accelerator. The Therasim-750 Simulator is used for the planning of the tangential fields and dose distribution for each patient is carried out on TP-11 Computer system. The extent dose uniformity to the breast and surrounding nodal areas is confirmed with the dosimetric measurements in a specially designed breast phantom. All the measurements were carried out using TLD crystals, Our dosimetric results shows the doses to the nodal areas were 15 to 20% less than the mid breast. In routine course of treatment this is compensated with an additional direct hockey stick field for nodal irradiation. During the last 4 years, we have treated a total of 96 breast cases with this technique. Our clinical results show fair to excellent cosmesis in all cases except fibrosis in two cases and local recurrence in one patient. Thus with this technique long term controls and improved cosmesis is being achieved.
[ABSTRACT]   Full text not available  [PDF]
  457 44 -
Quality Control In Radiotherapy
Rajendra Kumar Lad
July-December 1986, 11(3):56-56
The purpose of this paper is how to improve the quality of radiotherapy. In this paper I described how many factors are essentially required for quality control in radiotherapy. I also described, on the basis of survival curse theory, why it is essentially required particularly in those countries where large number of cancer patients are being treated on one unit. In this paper I used theoretical with example, analytical and experimental methods with necessary data. I also used some diagrams for verification of the different kinds of task for the radiation therapy units which is very essential for quality control of the radiation-therapy. In this paper I tried to explain the following points in details: - 1) Accuracy required in radiotherapy, 2) Possible source of errors and how to avoid it, 3) Dosimetry check, 4) TLD measurement and its advantages 5) Mechanical acceptance test 6) Radiation test, 7) Radiological protection test. RESULT :- The above mentioned points will give us an over-all error of + 50% to + 6% or sometimes little bit less than + 5% which is just above (i.e. more than + 5%) or just below (i.e. less than + 5%) that we would like to achieve for quality control & improvement of cure rate in cancer patients. Finally I would like to state that the quality control in radio-therapy is essentially required for improvement of cure rate in cancer patients and will be achievable with help of above mentioned points but notwithstanding that it is also related with the stage and depend upon biological and anatomical site of lesion.
[ABSTRACT]   Full text not available  [PDF]
  460 36 -
QC Aspects In Determination Of Left Ventricular Function By Equilibrium Gated Blood Pool Study
M M Rehani, A Mondal, B K Das
July-December 1986, 11(3):290-290
The determination of left ventricular function by multiple gated equilibrium blood pool imaging is a routine procedure practised very widely. The Quality Control (QC) aspects of complete procedure including also the ejection fraction (EF) calculations require some attention as there is paucity of literature in this area of the field. The calculation requires definition of region of interest (ROI) on end diastolic and end systolic frame and a background region. This definition of region can be done manually, fully-automatically or semi-automatically. Out concern is to analyse QC aspects in two of these modalities viz the first and second. Fifty patients referred for routine left ventricular function study by radionuclide technique were taken up for this study. The invitro RBC labeling was achieved by IV administration of Sn-Pytophosphate kit containing upco 1 mg if stannous chloride followed by administration of 20 millicurie of Ic-99m pertechnetate 30 minutes later. Labeling efficiency to the tune of 96-98% was achieved. ECG gated data acquisition was obtained in LAO view using Sciemens Gammasonic Gamma Camera coupled to Scintiview data processing system. The data was recorded on Floppy diskettes. Two modalities of EF calculation were compared - manually and fully automated technique. The results show that a) localisation of left ventricle in the centre of field is essential for getting accurate results b) magnification between 1.5-2.0 is recommended c) co-relation co-efficient of 0.92 between manually and fully automated method of EF calculation was achieved by removing interobserver variation. Limitations of fully automated programmes have been enumerated.
[ABSTRACT]   Full text not available  [PDF]
  444 38 -
Radiation Dosimetry Of Selectron HDR Pellets In Different Intracavitary Applicators In Perspex -Water Phantom And In Patients
P S Negi, D R Goyal, K Das, B D Gupta
July-December 1986, 11(3):185-185
A water immerssible cylinderical phantom in Perspex was designed and fabricated for holding vaginal and intrauterine tubes of different HDR applicators in their respective geometries. Doses around single and multiple combinations of Cobalt 60 source pellets with and without water in different planes were measured with the Therados AB solid-state dosimeter. Measurement were used to derive correction factors for attenuation through the substance of applicators and water. Reconstruction of the locations of source pellets were performed with the help of orthogonal radiographic views of the water phantom taken with the help of Siemen's Simulator which was earlier quality checked for this purpose. "TP-11 seed program" normally used for LDR calculations was suitably adjusted for HDR calculations. Doses thus calculated were computations and experimental measurements was further checked against thermolumniscent dosimetry. This work formed a part of quality assurance program in HDR brachytherapy dosimetry at our centre.
[ABSTRACT]   Full text not available  [PDF]
  429 43 -
Hyper Fractionation Teletherapy In Cancer Cervix
A.K Dixit, T.N Edoliya, Y.C Agarwal, P Narain, A.K Shukla
July-December 1986, 11(3):338-338
Patients of state IIB, IIIA and IIIB having exophytic growth and high hypoxic content do not respond well to conventional five fractions a week (5 F/w) radiation treatment. Two fractions a day (10 F/week) radiation with an interval of five hours in between was tried in such cases with a radiobiological basis that normal tissue recovers in 3-4 hours, while malignant tissue takes 6-8 hours to recover. Local control in the form of complete regression of visible disease was such more (84%) in the trial group (2 F/day) in comparison to only 56% in control group (5 F/w). This facilitated intracavitary brachytherapy in larger number of patients. Present study is of three years duration consisting of fifty patients each in trial and control group.
[ABSTRACT]   Full text not available  [PDF]
  431 37 -
Dose Specification In Intracavitary
Andree Dutreix
July-December 1986, 11(3):148-148
Different systems for intracavitary applications of radioactive sources have been initiated at the beginning century. Based on the clinical experience, rules have been proposed related to the geometry of the application, to the relative source activities and to the dose and volume specifications. It has been opportune to reconsider dose and volume specification because radium is progressively replaced by gamma-ray emitting substitutes for which the old systems are not always suitable. Furthermore SI units should be used and computers are routinely used for calculations. ICRU has published recommendations on Dose and Volume specification for reporting Intracavitary therapy in gynecology. ICRU recommendations are presented regarding the description of the technique used, the total reference air karma, the description of the reference volume, the absorbed dose at reference points and the time dose pattern.
[ABSTRACT]   Full text not available  [PDF]
  414 42 -
Computer Aided Radiation Therapy Data Recording System
Rajendra Kumar, G K Rath, R C Joshi, T Ganesh, Naresh Shrivastava, Manjit Singh
July-December 1986, 11(3):95-95
S-810 micro computer (Manufactured by Uptron India Ltd.) has been interfaced to RFA- 3 and DPD-5 (manufactured by M/ s. Therados of Sweden). Software has been developed and tested for both REA-3 and DPD-5. The software package for DPD-5 monitors the radiation dose given to a patient and logs the on-line radiation dose data in a file for later references. A check is also provided to make sure that the radiation doses are within the set – limits for all channels. The software package for RFA-3 supports the measurement of dose distribution in a water phantom. Different scanning modes can be selected under software control. The data collected in the file can be either dumped onto the line printer or plotted directly on to the X-Y plotter. Both the above mentioned software packages have been developed in the PL/s language. This language has been developed by M/s. Softek on the microcomputers specifically for real-time applications and is a sub-set of PL/1. The software developed is very useful in handling large amount of dose data measured by DPD-5. Also, it enables to collect the beam data by means of RFA- 3 in a form which is compatable to the treatment Planning System requirements. The S-810 Uptron microcomputer is portable and thus can be moved to the site along with either DPD-5 or RFA-3.
[ABSTRACT]   Full text not available  [PDF]
  425 23 -
A Software Implementation Of ICRU 21 Based Electron Protocol For A Desktop Computer Controlled Waterphantom Dosimetry System.
Daljit S Saini, Arne Roestel
July-December 1986, 11(3):111-111
While the ICRU# 21 protocol is straight forward, the sequence and practical methods to apply the various correction factors. A computer driven 0.1cc micro chamber is used to measure ionization. Allowance can be made for a displacement correction at the time of data acquisition or analysis. Virtual source distance adjustment and divergency corrections may be made in the Rp (practical range) calculation. The appropriate corrections for Ce and perturbation (Pwg) are used in the conversion of ionization to relative dose. The resultant depth dose curves can be overlayed on the ionization curves as a means of visual comparison. The results obtained by solid state detectors and film dosimetry methods are compared with the software converted ionization data. Physicist, Radiation Oncology, Holmes Regional Medical, Melbourne, FL 32901 Product Manager, Multidata Systems International Corp. St. Louis, MO 63122
[ABSTRACT]   Full text not available  [PDF]
  420 24 -
A Comparative Study Of Two Computerized Treatment Planning Systems Used For Brachytherapy Dosimetry
P S Negi, S L Kapoor, B D Gupta
July-December 1986, 11(3):157-157
Different idealized implants, surface moulds and intracavitary applications calculated by A.E.CL. TP-11 system and TSG Radplan computerized treatment planning system were compared. A protocol was designed to test the software for brachytherapy and its associated reconstruction technology of both the planning systems. This quality assurance program will help the user to appreciate the capabilities and limitations of the two systems.
[ABSTRACT]   Full text not available  [PDF]
  399 44 -
Photodynamic Effect On He-La Tumour Cell Line With Lasers And Photosensitizes
S Ganesan, V Masilamani, S.P Thiagarajan, S Subramaniam, S Natarajan
July-December 1986, 11(3):352-352
Photodynamic therapy (PDT) of its specificity and its capability of irradiation and regression of tumour even in internal organs. The technique involves laser irradiation of photosensitizor which specifically and preferentially binds on tumour cells. This paper reports the results of one such investigation with He-La tumour cell line as target and lasers as light source and a few dyes as sensitizer. The laser used are ultraviolet Nitrogen laser (100 KW nower, 10 ns pulse duration, I Uz repetition rate) and He-Ne (15Mw). The sensitizers used are HpD, Acridine orange, etc. The cell damage is measured by counting viable cells. The investigation shows that cell damage is decisively higher when laser and sensitizor are used in conjunction then when each is used individually. Results of cell damage for each laser as a function the nature of sensitizer, its concentration, laser energy dosage and incubation time are presented.
[ABSTRACT]   Full text not available  [PDF]
  405 38 -
Use Of Radiation Induced Chromosome Aberrations In Radiological Protection
G.S Pant, A.K Basu
July-December 1986, 11(3):556-556
Ionizing radiations have been extensively used in therapeutic and diagnostic radiology and also in biomedical research. The risks In biomedical research. The risks in handling the radiation sources are not unknown, if the safety guidelines are not followed properly. Even if all the safety precautions are observed, there are unforeseen situation leading to radiation exposure of the occupational workers or a section of population. In individuals by physical methods is rather hypothetical. Thus we have to depend only on biological effects produced by radiation exposure. It is well known that among all the biological effects induced by radiations, chromosomal aberrations are the most conspicuous and reliable. We have established dose response relationship and have been using them to estimate the radiation done in partial/whole body exposures. Results of our experiments and their possible use in radiation dosimetry particularly for radiological protection shall be presented.
[ABSTRACT]   Full text not available  [PDF]
  400 42 -
Parameter Specification Required For A Semiconductor Detector
Goran Rikner
July-December 1986, 11(3):587-587
Semiconductor detectors are frequently used in radiation dosimetry. During the last years several papers have been presented showing that there are many parameters to take into consideration in order to describe the characteristics of a semiconductor detector. In this presentation these parameters are described and discussed. 1) Type of doping. n-or p-doped detectors can be used. For an n-type detector a nonlinear response with dose rate will be developed as an effect of radiation damage. p-type detectors will not see this drawback. p-type doping also shows a less sensitivity loss when radiation damaged. 2) Doping level. An increased doping level will normally give shorter life times and thus also a lower sensitivity of the detector. The maximum dose per pulse for linear response is also depending on the doping level. The higher doping level the higher the linearity will stay between dose rate and signal. 3) Preirradiation level. Except a sensitivity drop and a dose rate non-linearity (for n-type detectors) the sensitivity variation with temperature (SVWT) will increase as a function of preirradiation. Unirradiated the SVWT will be less stays fairly constant. 4) Mechanical description. As for other detectors the knowledge of the mechanical of the detector is very important. Incapsulation, connector design, energy compensation etc. must be described in detail as the effective measuring point and directional dependence will change with these parameters. 5) The effective measuring point should be given with an accuracy of 0.5 mm for at least one radiation quality for a detector to be used in a water phantom and within 1 mm if used in patient dosimetry. 6) Directional dependence. The directional dependence for must be known, as if correction factors are applied to the reading they have to be weighted in accordance to the directional dependence. 7) Detector volume. Both the detector area and the effective measuring volume must be known as the statistical noice in the reading is correlated to the detector size. The spatial resolution is also depending on the detector size. 8) Leakage current and connection to electrometer. In order to avoid incorrect readings it is important to use a detector with as small leakage current as possible in a short curcuit mode to an electrometer. The electrometer itself must have a low input offset drift but not necessarily a high electronic gain.
[ABSTRACT]   Full text not available  [PDF]
  401 39 -
ECG Simulator And Electronic Lead Selector
Padma Ranjani, M Samuel, V Chandrasekar, G.N.S Prasad
July-December 1986, 11(3):324-327
Full text not available  [PDF]
  236 203 -
Development Of Localization And Radiation Dosimetry System For High Dose Rate, Surface Applications At PGI Chandigarh
P S Negi, B D Gupta, D R Goyal, R K Munjal, K Das
July-December 1986, 11(3):218-218
Individualized Perspex treatment shell technique with fixed treatment distances from irregular surface topography for HDR selectron tubes was developed for irradiating recurrence along the surgical scars or skin nodules of breast. Simulation technique was evolved to localize pellet sources for generating data input for computerization of dosimetry. Selectron of prescription planne and the optimum orthogonal radiographic views for identification of each individual pellet were the problems surmounted. Computed dose rate distributions in different planes were then used for dose prescription. HDR dose-time schedules employed were evolved through a normalization constant for LDR-HDR equivalence derived from a modification of radiobiological evidences projected by Turesson and Notter (1979, 1984) and Morrison (1979). Fifteen patients treated by this dose time relationship facilitated the evolution of a HDR-surface application system by the present investigators.
[ABSTRACT]   Full text not available  [PDF]
  403 35 -
Present Status Of Dosimetry In Nuclear Medicine Procedures
E Werner, P Roth, Ges F Strahlen
July-December 1986, 11(3):261-261
In nuclear medicine radioisotopes are used to label a wide variety of compounds. The biokinetic behaviour of such radiopharmaceuticals which are administered perorally, intravenously, or by inhalation my significantly differ from the blokinetics of ingested and inhaled radionuclides as given in ICRP 30. For the assessment of radiation exposure in nuclear medicine procedures the biokinetic parameters of each radiopharmacon have to be evaluated. Normally, the quantitative measurement of the retention functions of all relevant organs is not possible. Therefore, suitable models of the metabolism of the particular radiopharmacon have to be installed. It will be shown that the ICRP models for lung and gastrointestinal tract are sometimes not adequate. If a suitable model has been assessed, dose calculations may be performed applying the cumulative activities and values of specific effective energies (MIRD 11). The influence of various parameters e.g. type of radiopharmacon, age and underlyning disease of the patient on radiation exposure in nuclear medicine investigations will be discussed.
[ABSTRACT]   Full text not available  [PDF]
  397 39 -
A New Method For Designing The Parallel Square Hole Gamma Camera Collimator
Rajendra Kumar, G S Pant
July-December 1986, 11(3):285-285
It has been observed by one of us that the detection of a cold lesion of a given size is easier if it is located in larger organ (with radioactive distribution) than in a smaller organ provided the contrast is high enough. This type of dependence of detect ability of cold lesion has not been incorporated in the design of gamma camera collimator. In this paper we have attempted to develop the theory for designing the parallel square whole gamma camera collimator. The method takes into account the size of the cold area and of the surrounding hot area in the organ. The associated problems in the design have been discussed and usefulness of an image processing device; so-called collywobbler has been investigated.
[ABSTRACT]   Full text not available  [PDF]
  404 27 -
Safety Aspects Of Medical Use Of Ionising Radiation
I Shai
July-December 1986, 11(3):552-552
It is proposed to keep the Radiation Protection Regulations of a country under constant review and subject to modifications in pace with the modern developments in Medical Uses of Ionising Radiation at the patient level. Very high doses of radiation are used in Radiotherapy Centres for cancer treatment. It is suggested that old and developing centres and new centres of Radiotherapy should be graded in four groups of centres have been clearly and separately laid down in this paper., so that National Radiation protection Regulations of a country could be drafted and implemented with lease difficulty. It has been proposed in the paper that Radiotherapy Centres falling in the group 'D' should be improved so that these become fit to be classified in C:B or A groups. It is brought out that additional grants should be made available for necessary improvements in Radiotherapy Centres falling in groups B & C as per National Radiation Protection Regulations propagated by the competent Authority of a country. It is further suggested that enforcement of National Radiation Protection Regulations should be vested in Physicists who are qualified trained and duly recognised by the Radiation Protection Regulatory Board of a country, as the Radiological Safety officer.
[ABSTRACT]   Full text not available  [PDF]
  372 55 -
Measurement Of Dose Equipment Index Quantities In The Sphere Using TLD Discs.
K.S Shenoy, K.L Popli, S.K. Gupta, D Krishnan, R.K Kher, S.J Supe
July-December 1986, 11(3):531-531
ICRU has recommended a issue equivalent sphere of 30 cm diameter for measurement of both shallow and deep dose equivalent index quantities. This paper gives our results of measuring these quantities with the TLD dises used in personnel monitoring in BARC. A spherical glass container (30 cm diameter) filled with water and TLD dises placed along a Perspex carrier was used. The dosemeter disc is a Caso4:Dy embedded teflon disc (0.8 cm thick and 13.6 mm dia, weight 260 mg). The sources used were 250 mCI of Ra-226, 15 Ci of Cs-137, 2 Ci of Co-60 and 2 Ci of Ir-192. All the exposures were carried out at a distance of 1 meter. Both the stationary and rotation modes (1 rpm) of the phantom were used. The results of the depth dose measurements in the sphere were fitted to a curvo for each of the energies and was used to arrive at the position of the maximum dose and the value of the peak dose. For all the above energies the position of maximum was at a depth more than 1 cm. The results would be discussed in detail and compared with theoretically computed values and conversion factors for measured surface doses to maximum dose would be presented.
[ABSTRACT]   Full text not available  [PDF]
  404 23 -
Microcomputer Treatment Planning System
Anthony Chung-Bin, David Chung-Bin
July-December 1986, 11(3):112-112
Since 1974 Rush-Presbyterian-St. Luke's Medical Center has used a PDP 11/45 computer by Digital Equipment Corporation (DEC) for Radiation Therapy treatment planning. The software package we have developed for this purpose can computer brachytherapy plans (using the Stovell and Shalek method for both intracavitary and interstitial implants), external photon beam plans (using Cunningham's method with correction for irregular field size, inhomogeneity and patient shape) and external electron beam plans (using Hogstrom's method). The software has been used extensively during the last ten years by eight associated cancer treatment centers in the Chicago and Northern Illinois area. Over this time the software has proven to be reliable and easy-to -use. Recently we transferred this software to DEC's PRO-380 microcomputer; this inexpensive machine has computer power comparable to that of the PDP 11/45. The PRO-380 central processor is a J-11-based microprocessor with a PDP 11/70 instruction set. It has a half megabyte of memory, augmented by a ten megabyte Wincheste hard disk and two 51/4- inch floppy disk drives; the treatment planning system also includes a six-color graphic plotter, a printer, a 20 X 20 inch translucent digitizer and a communications modem. Except for the digitizer, all of the hardware is DEC standard equipment. This system is adequate to meet all the treatment planning needs of any moderate size radiation therapy center. It lacks the ability to input CT data directly from magnetic tape, but it can enter the contour, tumor volume and inhomogeneity from a CT scan using the backlighted digitizer. With the two floppy disk drives and the communications program one can transfer data and programs from other computers using floppy disks or a telephone line. This feature allows easy installation of new programs and lowers both the cost and the time of software maintenance. All of the hardware, the graphic input/output and the communications program are supplied by a third-party vendor as a system.
[ABSTRACT]   Full text not available  [PDF]
  389 36 -
3D Dose Distributions
Andree Dutreix
July-December 1986, 11(3):166-166
One of the greatest advantages of the use of computers is to be able to provide dose distributions for treatment conditions for which manual calculations are not feasible. Three dimensional calculations can be performed nowadays with most of the treatment planning systems available. They require the acquisition of multiple cross sections of the patient either by simple mechanical devices or with CT scanner. The first step in 3D dose calculation is the calculation of a series of several transverse planes throughout the volume of in: e- rest. In the second step dose distributions are calculated in fron: al or sagittal planes. These calculations are of special interest for irregular fields, for instance in mantle technique. The next step requires the use of CT scans with the display of dose distribution superimposed to the anatomical structures. The 3D display of the external contour of the body with the display of two planes of interest by digital dissection is the last improvement of the method.
[ABSTRACT]   Full text not available  [PDF]
  390 29 -
Xeroradiography : Principles And Applications In Radiation Therapy
Suresh M Brahmavar
July-December 1986, 11(3):247-250
Full text not available  [PDF]
  348 69 -
Experiences In The Planning Of Brachytherapy Departments From Radiation Safety Stand Point
Kanta Chhokra, P Sethulakshmi, P.S Iyer
July-December 1986, 11(3):526-526
For ensuring adequate radiation protection in brachytherapy departments, it is desirable that the radiation doses to the personnel are brought to levels as low as reasonably achievable and in any case, shall not exceed the levels specified by the International Commission on Radiological Protection (ICRP). To achieve this purpose, the primary mandatory requirements is that the brachy-protection norms. This Paper deals with the planning of brachytherapy departments using manual and/or remote after loading techniques. In brachytherapy wards alone need to be adequately shielded and the associated facilities of the hospital. In the case of department using remote after loading techniques, the installation housing the after loading unit needs to be planned and approved from radiation safety standpoint. The above planning takes into consideration the type of unit, the workload, occupancies etc. The planning of these departments are discussed in detail along with illustrations.
[ABSTRACT]   Full text not available  [PDF]
  367 50 -
A Radio therapeutic Clinical Trial Of Thrice Per Week Vs. Five Times Per Week In Oral Malignancies
Ishwar Chandra, T N Edoliya, Narain Prem, Y C Agarwal
July-December 1986, 11(3):62-62
121 Cases of oral malignancies have been treated by three fractions per week and the results are compared with 109 approximately identical cases treated by conventional five days a week with other parameters being identical. Radical irradiation was done by 6000rad in 6 week (1770 r.c.u) and palliative dose was 4500 rad in 4 week (1530 r.e.u) Tumour regression was found markedly superior by conventional fegime in radically irradiated cases but much less superior for palliative treatment. Acute and late reaction as well as tumour control at one year was better with daily treatment, more in radically treated cases, but superiority of daily regime was less marked in palliative treatment. Three fractions per week can be alternatively used for palliation in advanced cases.
[ABSTRACT]   Full text not available  [PDF]
  393 23 -
Total Skin Electron Therapy For Mycosis Fungoides Patients
Charlie C.L Chan
July-December 1986, 11(3):586-586
The physics measurements including field uniformity, energy distribution, and X-ray contamination of a total skin electron therapy technique for mycosis fungoides patients will be discussed. The set up will be described. The design of the field scatterer and its functions will be discussed. The treatment technique is evaluated by TLD measurements and clinical assessments. The total skin electron therapy is delivered using a 5 Mev electron beam from a medical linear accelerator calibrated to deliver 3.8 NeV electrons at the patient's skin surface. The treatment cycle consists of four fields, anterior, posterior, right and left lateral, and the patient is treated with one field per day and one treatment cycle per week with a total weekly dose of 400 rads. The total treatment will last for six weeks. Shielding are designed for the eyes and fingernails.
[ABSTRACT]   Full text not available  [PDF]
  376 39 -
Dosimetric Data Analysis Of Interstitial IR- 192 Implants Of Ant 2/3 Tongue Cancer
S M Deore, R L Bhalavat, S Suenerwala, M P Scaple, R Pandhi, K A Dinshaw
July-December 1986, 11(3):216-216
The analysis of dosimatric data of particular site Implants and correlating it with the clinical is of great importance towards a standard approach in dose Prescription. The present investigation was undertaken in Ir-192 implants of ant.2/3 tongue. Thirty seven implant cases of ant. 2/3 tongue cancer treated primarily with radiation therapy have been analysed. There are 11 cases of T1 stage and 26 cases of T2 stage. The local control results for T1 lesion were 88% and 42% for T2 lesion. This high rate of failure in local control of T2 lesions raised double about the dose delivery with Ir-192 implants. In the anslysis of decinstris date, more elaborate dose distributions at different levels of each implant, dose rate affect, geographic miss and poor implant geometry factors were studied. The clinical results found, it was concluded that the dose rate influences the clinical out come. After reviewing the dose distributions at the tongue surface level; it use found that in almost all the tongue surface was under dosed by about by about 20 to 30%, However in come of implants, besides under dose on tongue surface geographic miss and poor implant geometry were also the reasons for local failures. Thus in case of tongue implants the doses should be prescribed with the dose distribution at proximal transverse section, under doses or overdoses because of poor implant geometry should be compensated with differential unloading of the implant.
[ABSTRACT]   Full text not available  [PDF]
  387 27 -
Computer Applications In Radiotherapy
J.R Cunningham
July-December 1986, 11(3):594-596
The use of computers in radiotherapy has a history of more than twenty-five years of development. The earliest applications were to give faster and more accurate answers to dosimetric problems already handled by manual methods. Soon, however, the development of computer methods became so extensive that approaches problems in radiotherapy changed extensively. In recent years it has been realized that a rather surprisingly high degree of accuracy is required in the knowledge of and the delivery of dose in radiotherapy. Computers have been used to assist in the whole sequence of things that are part of carrying out a course of radiotherapy. A few examples are; the acquisition of patient anatomical data, the acquisition of radiation beam data, the display of this data, the calculation, display and plotting of isodose distribution as part of treatment planning, the optimization of these dose distributions, controlling the treatment machine, checking and affirming the set-up and analyzing the results of treatment. The computer is an integral part f CT and MR imaging system and quite exciting work is being done in processing and displaying images for radiotherapy. As already mentioned much development is still being done. In improving and increasing accuracy in methods of dose calculation. Perhaps the most important contribution of all is in analyzing the results of treatment and correlating response of tissues with doses received, a project which is sure to have an impact on radiotherapy prescriptions themselves. 1. J.R. Cunningham, Dose calculations in photon and Electron Beams using elemental pencil beams, paper this conference. 2. K. Mah, J. Van Dyk and T. Keane. Quantitative measurement of lung density changes following lung irradiation. Proceedings, 8th international conference on the use of computers in radiotherapy, IEEE computer society press, 1984 and two papers in press.
[ABSTRACT]   Full text not available  [PDF]
  355 57 -
Current Regulatory Requirements For Establishing Radiotherapy Facilities In India
P Sethulakshmi, P.N Ramaswamy, Kanta Chhokra, G Subrahmanian
July-December 1986, 11(3):506-506
Radiation Protection has assumed more importance with the extensive use of sealed and unsealed radiation sources for a variety of applications. Radiotherapy facilities such as Teletherapy, Brachytherapy and Nuclear Medicine have been growing consistently in the country, necessitating compre hensive radiation sources for a variety of applications. Radiotherapy facilities such as Teletherapy, Brachytherapy and Nuclear Medicine have been growing consistently in the country, necessitating compre hensive radiation protection programmes to be implemented by the Competent Authority. These facilities need to be approved from radiation safety view point by the Competent Authority before they are commissioned by the prospective users. Certain regulatory measures are formulated by the Competent Authority which should be duly fulfilled by the users of the facilities. In general, the requirements in respect of units, layout plans, staff, handling and monitoring equipments etc., are to be duly complied with, all the facilities. Further necessary authorizations from the Competent Authority have to be obtained, on fulfilling these requirements and surveillance by the Competent Authority will be done wherever required, prior the commissioning of the installation. In addition, Teletherapy facilities need approval of the "standing Committee on Teletherapy Units" and the Clinician handling Radionuclides for invivo studies has to obtain clearance from the Nuclear Medicine Committee. These requirements are discussed in detail in this paper & guidelines are given for persons intending to start these facilities in India.
[ABSTRACT]   Full text not available  [PDF]
  364 47 -
Physical Studies On Thermotron RF 8 Hypertherhia Machine
I.S Balakrishnan, H.M.S Reddy
July-December 1986, 11(3):408-411
Full text not available  [PDF]
  367 43 -
Intraoperative Electron Beam Therapy (IOEBT) -Putting The Dose Where The Tumour is
R K Ahuja, R R Dobelbower, Ann D Hollon, Andrew J Milligan
July-December 1986, 11(3):90-90
High dose external radiation therapy for resistant or unresectable tumors is limited due to normal tissue tolerance. In the United States of America, there is a recent upsurge in new techniques available including hyperthernia, IOEBT and combined modality treatments. the Medical Collage of Ohio at Toledo, ohio, has an 18 meV and a 6 meV Clinac Linear Accelerator. The former produces 10 meVp Xrays and 6-18 meV electrons. The high energy radiation therapy room was modified so that operative procedures could be performed and IOEBT could be delivered at the time of Surgery. Special attachments for IOEBT were custom made to attach to the treatment machine and Lucite applicators were constructed for actual delivery of electron beam therapy. The lucite applicators are round or rectangular in shape. Various sizes are available to match the treatment profile to the disease profile. A telescopic device gives a "machine's eye view" of the area to be treated. A total of 100 patients were treated between August 1983, and March 1986, in the intraoperative radiation therapy suite. There is no added morbidity or mortality related to the addition of IOEBT. Technical considerations, morbidity and results of treatment will be discussed in detail.
[ABSTRACT]   Full text not available  [PDF]
  380 25 -
MRI Research In China
Lin Yiqun
July-December 1986, 11(3):254-254
In Recent years Chinese researchers and physicians have been paying great attention to MRI Technology and its clinical applications. For example, the researchers of the Academy of Sciences of China have done great work at MRI technology and equipments. Several Medical Centers in China have imported foreign MRI machines which have been set up or have been setting up Hundreds of patients have been examined at Nanfong hospital, the First Military Medical College, Guangzhou, with MRI. In order to communicate the experiences on medical imaging technologies, the Association of Medical Imaging Technologies of China has been set up in May 5, 1984. And the third meeting of this association was held in Beijin in June 18-21, 1986.
[ABSTRACT]   Full text not available  [PDF]
  381 23 -
Theoretical Calculation For Thermal Test For a Type B Package Containing 10000 Ci Of Cobalt - 60 Teletherapy Source
Amiya Sharma
July-December 1986, 11(3):527-527
A package which is designed to withstand normal conditions of transport is a Typo A package. A Type B package in one which is designed to withstand accident conditions of transport. In order to Demonstrate that a package own indeed withstand accident conditions of transport it has to fulfill certain test requirements. The tests applicable to type B packages include the mechanical test, the thermal test and the water immersion test. The response of the package to the tests can be assessed either by the actual performance of the test on full-scale/reduced scale model or by calculative methods. Here we present the results of our theoretical assessment of the ability of a package intended for the transport of a cobalt-60 teletherapy scarce of strength 10000 Ci to withstand the thermal test. This test requires the operation to be expected to a thermal environment of temperature 800o C fer 30 minutes. First we have studied the temperature distribution in the lead container by solving the best conduction equation. Considering the package to be a sphere, the equation for limar flor with internals surfaces is. The solution of this equation indicates that the temperature inside the container is such more than the melting point of lend. This will lead to thermal expansion of lead cursing stress to develop within the container. This may result in oraoks in the steel encasing. To avoid this, acne wood lining to the package is necessary so that the temperature rise may be controlled. How much wood lining should be provided and what will be the effect of the wood on temparature distribution is also calculated here.
[ABSTRACT]   Full text not available  [PDF]
  373 30 -
Progress & The Current State Of Art Of C. T. Systems
M S N Murthy, J R Mallard
July-December 1986, 11(3):238-238
In 1968 Hounsfield finally decided about taking the major step of using his earlier work on imaging in the medical field. He used a lathe bed for scanning a phantom. The scan time was nine hours and the processing time two hours. Of consequence was the final picture of a human brain in which the grey and white matter could be clearly distinguished. The first patient was scanned in 1972 in 4 minutes, already a great progress in scan time. This was the first generation scanner, the second generation being the translate-rotate type, the third generation being the rotate-rotate type and the fourth generation being the fixed ring detector system. The last three types are in current use. This has been the progress in the scanning system. The progress has been rapid in the computer, x-ray and detector areas. Progress in the gantry section has helped reduce scan time to as low as 1 sec in third and fourth generation scanners thereby eliminating motion artefacts. Finer collimation has improved resolution to a great extent helped along by higher energy rotary anodes with finer foci and also by smaller detector sizes. The detectors in greater use being solid-state detectors and xenon gas detectors. Software development has helped image manipulation and analysis of data. Three dimensional imaging facilities are being offered by a few companies. Faster processors offer near real times images. The choice of image storage facilities are vast with magnetic tape, multi format hard copiers, hard disks, floppy disks, and optical disks. Speed of access to data and mass storage being the deciding factor.
[ABSTRACT]   Full text not available  [PDF]
  376 26 -
High Efficiency Ferrite Transformer Used With Broad Loop RF Hyperthermia Applicators
M.J Birjandi, K.V Ettinger
July-December 1986, 11(3):412-412
Use has been made of the commercial broadcasting BBC transmitters to provide Radio-Frequency power into broad loop applicators for the use on the extremities and on the trunk at 27.12 MHZ. A matching network has been designed and fabricated to meet the requirements for the intermediate stage between the transmitters and the broad loop applicator with a diameter of 26.7 cm and 20 cm long The network employs an UN-BAL ferrite transformer as an intermediate impedance magnifier. Experiments have been carried out to determine the optimum combination for the transformer in order to determine the efficiency of power transfer through t o the broad loop results show 88.9 % and 64.2 % efficiency of the Input RF power to heat convertior by the broad loop, using 1.5 it and 1 lt. cylindrical liquid phantoms, with a NaCl concentration of 0.9% of similar quality factor as an average thing and arm respectively. Temperature rises of 8.5 and 9.2 degree C. have been recorded in the 1.5 lt. and 1 lt. phantoms exposed for 10 minutes to 100 watts of input RF power. The power input obtainable from the commercial broadcasting BBC predicted that each ferrite transformer can only handle about 500 watts of RF power.
[ABSTRACT]   Full text not available  [PDF]
  371 30 -
Presentation Of Volume Dose Information In Non-Coplanar Radiotherapy Treatment Planning
E K Procter, T J Bateman
July-December 1986, 11(3):110-110
The purpose of this paper is to discuss the dose presentation techniques used to represent three dimensional dose distributions on a commercial treatment planning system, the General Electric Target System. There are two basic techniques for display and presentation of three dimensional dose information for radiotherapy treatment planning. One approach is to produce and display isodose surfaces superimposed on surface representation of patient anatomy. The main benefits from this technique are the immediate recognition of relative geometry within the patient and an overall conceptual understanding of the dose distribution. However, this form of display gives mainly qualitative rather than quantitative information. For example the margin between isodose surface and target surface is only visible around the extreme margins of the target volume. The other more widely applicable technique is to use planar dose displays where the dose distribution is displayed on any plane through the irradiated volume. This technique is typically very much faster than isodose surface displays and can be implemented on hardware configurations of much lower cost and complexity. To achieve the full benefits from three dimensional treatment planning using any form of graphics displays for dose distributions, it is becoming clinician and physicist responsible for patient treatment. We have implemented a volume dose calculation for this purpose which provides the user with tabulated tissue volumes receiving doses in specified ranges. This information is categorised into tissue types, for instance tumour volume, target volume or specified internal structures. The detailed information available from such volume dose statistics will give the clinician a much more thorough understanding of the likely problems associated with the particular treatment.
[ABSTRACT]   Full text not available  [PDF]
  377 19 -
Protection Of Patients In Radiation Medicine
Cesar F Arias
July-December 1986, 11(3):493-493
General principles of radiation protection of workers and population are applicable to medical installations, but the protection of patients deserves special considerations. Medical sources of radiation are by far the most significant contribution to the collective dose of any population; therefore efforths should be done to reduce such contribution as much as reasonably possible keeping of the same time every real benefit to the health of people. The non-thereshold linear hypotesis between risks and doses is the present support of radiation protection philosophy as recommended by the International Commission of Radiological Protection (ICRP). The present work analyze its implications on individual and collective basis. It is shown that even when a single radiological procedure con generate a "negligible" risk for a given person, the collective dose may be relevant if many people are irradiated in similar procedures and the associated detriment, expressed as the mathematical expectation of harm, may be significant. Such considerations provides basis for a better judgment of justifications and optimization of practices, particularly when generalized procedures of radiological surveillance are imposed to groups of populations. The work shows that reduction of unnecessary doses in radiation medicine results in appreciable reduction of collective doses and its associated detriment. Such reductions can be achieved by promotion and enforcement of utilizatior, of appropriate equipment and techniches as well as a good policy for training of physicions and physicist. Argentine experience on adoption of standars of quality and training programs is commented.
[ABSTRACT]   Full text not available  [PDF]
  359 33 -
Ultrasound Hyperthermia : Matching The Isotherms To Asymmetric Tumour Volumes
M.S.N Murthy, D.J Watmough, J.R Mallard
July-December 1986, 11(3):396-396
Studies were made here at Aberdeen using plane' and focussed- transducers to generate ultrasound hyperthermia in vivo. Having encountered problems of heating normal tissue along with the tumour tissue using plane and overlapping ultrasound fields-the clinical system' comprised of an array of seven focussed ultrasound transducers. The usefulness of this system to elevate the temperature of the malignant tissue selectively has been proved in trials phantoms and during one clinical trial. The collective heating of the entire tumour mass simultaneously was not very easy. This Jed to the development of a system which would overcome the above problems. A system comprising of individually driven transducers, the angles of which can be varied about its vertical axis, has been developed. The power to the individual transducers in the array can be varied independently. This system when used in trials on phantoms and during one clinical trial. The collective heating of the entire tumour mass simultaneously was not would overcome the above problems. A system comprising of individually driven transducers, the angles of which can be varied about, its vertical axis, has been developed. The power to the individual transducers in the array can be varied independently. This system when used in trials on phantoms showed its capability of heating larger areas simultaneously. Qualitative studies made using liquid crystal displays and also liquid surface levitation showed the flexibility of the system to generate tumour contour dependent, isotherms. Temperature measurements were made using a multijunction thermocouple array. As many as six to sixteen thermocouples spaced over 6cms to 10cms were used. The reference junction being in an ice water medium. The thermocouples were made, calibrated and tested prior to each trial. However, the disadvantage of this system is its inability to treat large tumour volumes. The volume to be treated is limited by the size of the transducer array, of the tumour volume not being resorted.
[ABSTRACT]   Full text not available  [PDF]
  361 26 -
Failure And Success Of Three years National Quality Assurance Programme-In Kuwait
M Al-Mudaires
July-December 1986, 11(3):528-530
Since the announcement in 1928 of the theory of the statistical technique in the United States the quality assurance was started. Since that many national and international bodies were actually involved in the quality assurance programme. In 1979 we started to think about quality assurance in diagnostic X-ray in Kuwait. The equipments for the tests was ordered in July 1982. The programme started on 21 March 1983 during that time it was a training of staff. The staff of each hospital was fully trained in quality assurance. The success of the programme was the awareness of the X-ray in Kuwait. The equipments for the tests was ordered in July 1982. The programme started on 21 March 1983 during that time it was a training of staff. The staff of each hospital was fully trained in quality assurance. The success of the programme was the awareness of the X-ray departments are capable of diagnosing most of the failures of their X-ray machines, so that the X-ray engineers must repair the machines correctly and to maintain it in proper way. The failure of the program was due to the administration where they are playing an important role of the success of the programme by 90% of the total program as well as the support of facility staff to such programme. Some of the reason of failures that most of the people are not aware of the value of such programme as well as they are not interested in the reduction of cost and exposure. From the past experience we developed another approach of making the people to be aware of the benefits of quality assurance programme by construction of quality assurance equipment, introduction of quality assurance courses in the university, continuous education courses and computerization of some equipment for the quality assurance. We feel from the experience that the quality assurance programme will continue with the help of the staff in each hospital if there are genuine support from their superiors.
[ABSTRACT]   Full text not available  [PDF]
  331 54 -
Dosimetric Of Iridium - 192 Line Sources
A Shanta, U B Tripathi, K R Das
July-December 1986, 11(3):217-217
Iridium-192 sources are increasingly used for interstitial applications for the cancer of various sites. The sources used are either in the form of wires or seeds. The dose distribution is almost identical for wire as well as seeds loaded at 1.0 cm intervals, except at distance very close to the source. The desired geometry of sources can be achieved by after loading techniques for various sites such as ca. breast, soft tissue sarcomas, some of the head and neck tumour and also wherever templates are used. In this paper, simple methods are suggested for the manual dosimetry of such implants. Dose distribution charts are given for sources of active lengths 5.0 cm, 10.0 cm and methods to use these charts for other active lengths are suggested. Calculated dose distributions are compared with experimentally measured values for a single line source and an array of line sources in two concentric circles, as in the case of a prostate implant. The agreement is quite satisfactory (+5%).
[ABSTRACT]   Full text not available  [PDF]
  355 27 -
Medical Cyclotron For Positron Emission Tomography (PET) : Evaluation Of Specific Problems Concerning Radiation Protection
R Horn Orni, P.L Bo, P Salvadori
July-December 1986, 11(3):494-496
Full text not available  [PDF]
  289 90 -
Radiation Effects On The Skin : Implications For Radiotherapy And Radiological Protection
J.W Hopewell
July-December 1986, 11(3):340-340
The skin is a tissue whose reaction to radiation has important implications for both radiotherapy and radiological protection. In therapy it is an important dose limiting normal tissue and damage induced by radiation must be weighed against the probability of tumour control. For occupational or environmental exposures, dose limits should be set which do not result in detrimental non-stochastic effects. The scope of the present ICRP guidelines for non-uniform exposures is limited by the paucity of biological data. The pig would seem to be an ideal model in which to undertake radiation studies on the skin; its structure and gross dimensions are very similar to those of human skin. Studies related to therapy, with fractionated doses of x-rays, have demonstrated a lack of correlation between early and late radiation damage to the skin. Late dermal damage was more severe than might have been predicted from the acute epithelial changes with doses per fraction of >4Gy. Irradiation with fractionated doses of fast neutrons (42MeV d+ Be) showed no difference in the RBE for early and late damage in the skin for neutron doses per fraction of 22Gy. With smaller doses per fraction the RBE for late damage was higher than that, for early effects. 1nveestigations related to radiological protection have involved the irradiation of pig skin with 6-emitting sources of varying energy; strontium-90 (E max 2.27deV) thulium-170 (E ms 0.97MeV) and promethium-147 (E max 0.225MeV). Sources of 0.1 - 40m diameter were used. The results of these experiments have indicated the limitations of the dose averaging procedure, asset out i n ICRP Publication 26, for sources of different energy. The studies have also shown that effects may be produced by the radiation-induced death of cells in the upper viable layers of the, epidermis (>70pm depth) and that the threshold dose for late dermal changes (atrophy) may be lower than that for early epithelial related damage. The target cell population, damage to which leads to late dermal atrophy, is at a 'significantly greater depth than the 70pm proposed in ICRP Publication 26.
[ABSTRACT]   Full text not available  [PDF]
  330 48 -
Manual Dosimetry Of Template Implant Using Iridium-192 Source
S Ramaswamy, M P Saple, D D Deshpande, S M Deore, R Pandhi
July-December 1986, 11(3):215-215
This paper aims to help the Cancer Centres, not having computerized treatment-planning system, in carrying out after loading template implants. The rigid geometry of templates implant is conductive for manual dosimetry; the temple is employed in treating cancer of anal canal, prostate and urethra. Iridium-192 sources are after loaded into the hallow needles of the template. The materials required and method of preparing the source inside a fine nylon tube are described. We found that when the source was followed by a stiff metallic wire source loading became smoother, reducing the exposure to the staff. According to Paris system, minimum dose rate for a triangular source array occurs at the intersection of perpendicular bisectors to the triangle. The dose rate at this point (Basal Dose rate) can be calculated from the given table, knowing the distance of each source from this point. The average of dose rates at similar points is found and when reduced to 85% will give the implant dose rate on which source removal is based. A transverse tomography, not necessarily CAT scan, will enable individualized dosimetry for all patients. Variation of dose rate along the template axis is shown; the selection of source length is based on this. A simple method is given to find the dose to critical organ using the lateral X-ray and a graph. The manual dosimetry can wall be supplemented by an atlas of dose distributions of template implant. Other Centres can be benefited by out method of preparing the sources and of coupling manual dosimetry with ready-made computer distributions for template implants.
[ABSTRACT]   Full text not available  [PDF]
  343 35 -
Computer Package For Planning Of A Radiation Therapy Installation
S G Sawant, G Janakiraman, P Sethulakshmi, P S Iyer
July-December 1986, 11(3):129-129
Our past experience shows that about 10-15 institutions approach this Division for Planning of new radiation therapy installation in a year. Normally a model layout giving a general idea about the area required and the approximate wall thicknesses is sent to these institutions. Based on this and their requirement the institution sends us an architectural drawing of the proposed installation. This plan is then carefully scrutinized from radiation safety stand point which involves lot of calculations. In most of the cases these plans have again to be modified taking into account the parameters such as the orientation of the unit, occupancies around the installation etc. A modified plan may not always be acceptable to the user due to architectural reasons, change of site etc. Thus the whole process is to be repeated at least two to three times which involves lot of time. To circumvent this difficulty computer package has been prepared which gives many possible plans of the installations for a given site out of which the most suitable one from the user's point of view can be selected. Some of the Salient features of this program are that a complete mapping of the exposure levels around the installation, amount of construction material like concrete needed will also be given. This will help in preparing a rough estimate of the cost of construction of the building.
[ABSTRACT]   Full text not available  [PDF]
  348 30 -
On The Genetic Status Of Normal Cells Surviving A Combined Modality For Tumour Therapy
M.S.S Murthy, K.B Anjaria
July-December 1986, 11(3):381-381
Hypoxic cells in tumors are known to be resistant to the lethal action of radiation. The radio-resistance of these cells is a serious challenge in the successful application of low LGT radiation i n the control of solid tumors. In the last two decades a number of combination modalities such as hyperthermia and radiation, hypoxic cell sensitizers an& radiation have been suggested to over-come this problem. The hypoxic cell sensitizers in themselves include a large number of diverse chemicals such as electron-affinic compounds, free-radical generators, thiol-reactive compounds, energy metabolism inhibitors, membrane-active drugs etc. They all act by different mechanisms. It is ell documented that the chances of a second tumor (at the site of irradiatior.) is higher in patients undergone radiotherapy than in normal population or in patients undergone surgical removal of the tumor. This is attributed to the genetic alterations induced by radiation in the surviving normal cells in the irradiated volume. Hence, the question asked, is, do these combined modalities enhance the genetic alterations in the surviving normal cells and thus further enhance the chances of a second tumor? In clinically oriented investigation, understandably attention has been focussed only on the efficiency of these-combined modalities to kill the hypoxic tumor cells. Hence they cannot provide answer to this question. However, elsewhere in literature, studies in diverse experimental systems on the genotoxicity of hyperthermia and a number of, chemicals used in combination modality have been reported. In this paper, we have attempted to review this literature to throw some light on the genetic status of normal cells surviving a combined modality.
[ABSTRACT]   Full text not available  [PDF]
  342 27 -
Imaging Of Sellar And C. P Angle Lesions By CT Scanner (CT-1010, EMI)
R K Goulatia, Rajendra Kumar, N K Mishra
July-December 1986, 11(3):239-239
The lesions in the Sellar and C. P. angle region of the skull are generally difficult to diagnose by C. T using normal collimation due to great differences in attenuation in the area. Sellar and C. P. angle regions have been investigated by using a specially designed collimator. The collimator enables the imaging of 5 mm thick slices and thus reduces the partial volume effect which is a prerequisite to obtain the correct values of attenuation. Results of 5 mm collimator have been compared to that of normal collimator (10 mm slice thickness). Some features of collimator design have also been discussed. This is of immense help in the second generation CT, where the latest generation CT is not available.
[ABSTRACT]   Full text not available  [PDF]
  332 34 -
Role Of Calcium During Hyperthermia
Arun Malhotra, Jack Kruuv, James R Lepock
July-December 1986, 11(3):413-413
This study was conducted with the goal of determining if hyperthermia increases the permeability of the plasma or mitochondrial membrane to Ca2+ and the effect of the resulting influx of Ca2+ upon cellular damage. Ca2+ can potentiate hyperthermic damage. Isolate rat hepatocytes are more sensitive to hyperthermia in high extra cellular Ca2+ and when treated with Ca2+ lonophore A23187. The degree of thermal sensitization is directly related to Ca2+ influx. In 15 mm Ca2+, Ca2+ influx due to increased permeability of the plasma membrane precedes loss of viability of hepatocytes. In 1-4 mm Cn2+, influx occurs during heating only after excessively long exposure to be the initial step in killing. Thus, Ca2+ influx at physiological concentrations of Ca2+ is not an early event in killing but it may plan important role in irreversibly programming a cell to death. Isolated mitochondria are very sensitive to elevated temperatures. Mitochondrial Ca2+ uptake is inhibited and mitochondrial Ca2+ release occurs in a dose dependent manner (81 and 100% release of accumulated Ca2+ occurs in 2 and 3 minutes respectively at 43 c) while no Ca2+ release is observed during the same time at lower temperatures. Differential scanning calorimetry (DSC) profiles indicate thermal denaturation of mitochondrial protein above 40 c, which may then cause the observed release of Ca2+. This suggests that release of Ca2+ by mitochondria may be more sensitive to hyperthermia than leakage across the plasma membrane. From the clinical point of view, increased calcium may theoretically offer an alternative approach to the design of hyperthermic protocols if a way can be found to differentially increase, even slightly, the Ca2+ permeability of cells in a tumor.
[ABSTRACT]   Full text not available  [PDF]
  326 36 -
Digital Radiography/Digital Fluoroscopy
Ei-ichi Takenaka, Ryosuke Hosaka
July-December 1986, 11(3):243-246
Full text not available  [PDF]
  208 153 -
Hematocytometrical Changes In Swiss Albino Mice After Intrauterine Low-Level HTO-Exposure
G.L Heda, A.L Bhatia
July-December 1986, 11(3):390-393
Full text not available  [PDF]
  289 68 -
Patient Dose In Diagnostic Medicine : How To Quantitate
D Krishnan
July-December 1986, 11(3):456-456
Diagnostic procedures, in medicine, whether they be with X-rays or radioisotopes, necessarily involve doses to part (s) of the body. Dose t o the gonads called the genetically significant dose (GSD) used to be an indicator of contribution to population exposure due to the particular procedure. This practice suffers from the obvious drawback that only genetic effects of radiation are taken into account, whereas the possible somatic effect on the population exposed is totally neglected. Alternative approaches to GSD are available in the literature. Many concepts are discussed with special reference to diagnostic radiology. Some of these are leukemia significant dose equivalent, malignancy significant dose equivalent, effective dose equivalent and somatically effective dose equivalent. The last mentioned quantity has been used in the tables given in ICRP publication 34, for a few types of diagnostic x-ray examinations. In this presentation, the basis of these calculations viz. effective dose equivalent (ede) concept is critically examined and a suggestion for further improvement is given. Quantitative radiation risk estimates, originally meant to be used for radiation worker, by the ICRP, are the basis of the ede concept. In this presentation, a new concept of population effective dose equivalent (pede) is proposed. This, it is hoped, will start new thinking on total risk. Ede is based on fatal cancers in adult population and genetic risk in first two generations. Instead if all cancers (i.e. morbidity) and all the hereditary effects are included in the total population, a higher number will be obtained. Thus population effective dose equivalent: (pede) = (p) X (ede) There p is the ratio of the two risks mentioned above. Available data (UNSCEAR, 1977, 1985) indicate that p will be greater than 1 and may be between 2 & 10. Strictly p should include population age distribution and radiosensitivity also. The effect of (pede) on weighting factors (WT) of individual organs is assumed to be small and so neglected. The reflection of this approach on the relative contribution of natural, medical and other man-made radiations to annual per capta dose to population is worth considering. This can be done after collective effective dose equivalents for different types of examinations (may be countrywide) using the above approach are calculated.
[ABSTRACT]   Full text not available  [PDF]
  312 40 -
Use Of CT Computer In Other Radiological Applications
Rajendra Kumar
July-December 1986, 11(3):133-133
A method has been developed to use the CT-1010 EMI scanner computer as a general purpose computer. The Main purpose of the work was to develop the method so that CT computer can be used more effectively for non-CT application also without affecting the CT software and CT image data in any manner. The RDOS general operation system has been installed on the same disc as EMI software. Care has been taken to make sure that RDOS remains compatible to the RTOs operating System on which the EMI software is based. Application software for patient data recording and analysis and also for X-ray film inventory has been developed and tested by making use of RDOS operating system. The Software developed for patient data recording can record directly on magnetic tape, the patient name, age, sex, x-ray number and disease code etc. This data can then be used by another program which can sort it out according to any stored parameter or combination of parameters. The programme for x-ray film inventory keeps track of the detailed x-ray film expenditure and the stock position in the store. The software development on CT computer allows the best use of its computer when the system is not being used for imaging work.
[ABSTRACT]   Full text not available  [PDF]
  323 29 -
Thermoluminescence Dosimetry In Radionuclide Hysterosalpingography (RN.HS.G)
M Lyra, P Sandilos, A Psalidas, Th Lyras, I Lordanou
July-December 1986, 11(3):484-487
Full text not available  [PDF]
  316 33 -
Our Experience In Planning Of Teletherapy Installations In India
P.N Ramaswamy, U.B Tripathi, V.K Bhargava, G Subrahmanian
July-December 1986, 11(3):507-507
There are 90 medical institutions in the country in which advice on planning of teletherapy installations has been rendered by the Division of Radiological Protection in the last 5 years. In initial periods many hospitals had caesium-137 and other fixed beam cobalt-60 units such as Eldorado-8, incorporating source strengths upto 3000 ci. These plans were supplied by AECL or other suppliers of the units and they were modified by DRP to suit Indian conditions. Later on, the use of Rotational Teletherapy units such as Theratron-60, Gammatron-R, Theratron-780 and Picker C-8 units came into prominent use. A standard plan which may normally accommodate either of these units upto a maximum source strength for 12000 Ci was designed, which had to be slightly notified in individual cases, depending upon the availability of area and the nature of occupancy all around and other factors such as cast and economy. The paper reviews the sequence of the development in the design of the plans of teletherapy units installed in this country up till now. It also brings out the modifications carried out in the plan supplied by the supplier of the units. This presentation will show how the institutions can acceptable to the competent authority.
[ABSTRACT]   Full text not available  [PDF]
  309 31 -
Measurement Of Radon And Its Daughters Concentration In A Multistoryed Building And In Indoor Atmosphere
A.J Khan, A.K Varshney, Rajendra Prasad, R.K Tyagi
July-December 1986, 11(3):543-546
Full text not available  [PDF]
  177 159 -
Dose Distribution In Total Skin Electron Beam Irradiation Using The Six-Field Technique
Azam Niroomand-Rad, Michael T Gillin, Ritsuko Komaki, Robert W Kline, Daniel F Grimm
July-December 1986, 11(3):93-93
Full text not available  [PDF]
  299 36 -
Total Skin electron Irradiation (TSEI) With Clirac-20, Clinical Experience In Treating Mycosis Fungoides.
G K Rath, Rajendra Kumar, Subhash Chander
July-December 1986, 11(3):91-92
Full text not available  [PDF]
  299 33 -
A Theoretical Approach To The Effect Of Dose Modifiers On Fractionation In Radiotherapy
D Krishnan, D.R Singh
July-December 1986, 11(3):339-339
The time-dose relationship in the practice of radiotherapy is important fox fractionation. Empirical formulae are available t o calculate the effective therapeutic dose for different fractionation schedules. These formulas however could not be directly used if the treatment includes dose modifiers much as chemical sensitizers, since they are the net resultant of many radiobiological parameters such as the 4R’s of radiotherapy. Effect of dose modifiers on these radiobiological parameters will help to analyse the effect on time-dose relationships. One of the many factors is the relation between dose and cell killing. Theoretical approach to the survival of the irradiated cell population has led t o various - mathematical formulations, which are available in the literature. Interpretation of these formulas with respect to fractionation scheme will be useful. One approach adopted by us will change the two-component male1 of cell killing. The survival curve parameters will change when dose modifiers such as hypoxic cell senstitizers are present during irradiation. The effect of this on both the dose per fraction and the fractionation schedule can be theoretically estimted, assuming the same therapeutic gain. Calculation suggest that a suitable fractionation schedule will need higher dose per fraction than the conventional dose and that the dose modifiers will have very small effect if conventional fractionation schedule is followed. It is hoped that this work will suggest conditions under which animal or human therapeutic trials should be conducted to decide whether a dose modifier is useful in practice or not.
[ABSTRACT]   Full text not available  [PDF]
  283 28 -
Design Considerations In After loading
Eric van 't Hooft
July-December 1986, 11(3):168-171
Full text not available  [PDF]
  265 45 -
Qualitative Assessment Of Performance Parameters Of Theratron 780 - A Nation-Wide Study
S K Kaul, W H Andrabi, S M Abbas, R K Kaul
July-December 1986, 11(3):59-61
Full text not available  [PDF]
  274 36 -
Evaluation Of Some Tensile Properties Of Calf’s Aortic Cylindrical Segments
R Martino, R Deredita, C Velussi, V Bettini, B Guerra, G Masiero, A Canagba, A Furlan, G Salvo
July-December 1986, 11(3):448-451
Full text not available  [PDF]
  277 30 -
Design Of A Narrow Field Collimator For Gall Bladder Activity Measurement
R N L Srivastava, V K Rohatgi, D K Hazra, J C Gupta
July-December 1986, 11(3):286-286
Full text not available  [PDF]
  283 23 -
Electronic Data Processing In Radio Immuno Assay
Gopal Sonai Muthu, Krishan Kumar Ahuja
July-December 1986, 11(3):291-294
Full text not available  [PDF]
  256 50 -
Role Of CT-Scan In Radiotherapy Treatment Planning
V K Nelson, M K Mahajan, A Peter
July-December 1986, 11(3):102-105
Full text not available  [PDF]
  223 81 -
Inhomogeneity Corrections - Significance Of The Advent Of High Energy Photons
S Jayaraman, F R Hendrickson, A Chung-Bin, L H Lanzl, M Rozenfold
July-December 1986, 11(3):142-145
Full text not available  [PDF]
  276 27 -
Radiation Protection Problems Due to Ultraviolet Radiation Used In Medical And Research Fields
Pala C De Murtas
July-December 1986, 11(3):557-560
Full text not available  [PDF]
  242 52 -
Dose Distribution In The Build-Up Region For Mega voltage Photon Beams :
V K P Kumar, P Bloch
July-December 1986, 11(3):8-11
Full text not available  [PDF]
  235 59 -
Positron CT Studies At National Institute Of Radiological Sciences
T A Iinuma, H Endo, H Shinoto, T Tamasaki, Y Tateno, N Nohara, E Tanaka
July-December 1986, 11(3):240-242
Full text not available  [PDF]
  265 28 -
Preliminary Experiences In Indigenous Cobalt Unit Development
B K Bhaskar, I S Balakrishnan, K S Viswanathan, A V Lakshmanan
July-December 1986, 11(3):121-124
Full text not available  [PDF]
  237 51 -
Determination Of Radiation Exposure To Patients And Personnel During Percutaneous Nephrolithotomy - A New Interventional Radiological Technique Of Removing Renal Calcult.
D.M Kooka, K Khandelwal, S.S Dagaonkar, S.J Supe, J.B Sasane
July-December 1986, 11(3):489-492
Full text not available  [PDF]
  232 56 -
Paterson - Parker Tables, In units Of Air Kerma
Govinda K N Rajan
July-December 1986, 11(3):223-226
Full text not available  [PDF]
  250 37 -
Magnetotherapy As An Adjunct To Radiotherapy
C Rethinasabapathi, M Jagadesan, P.C Rajaram
July-December 1986, 11(3):414-415
Full text not available  [PDF]
  244 35 -
A Study Of Radiation Doses To The Staff In A Department Of Radiology
B.L Acharya, A.A Chougule, G.R Agarwal
July-December 1986, 11(3):457-458
Full text not available  [PDF]
  226 51 -
Some Suggested Layout For Housing Teletherapy Units
V Jayalakshmi, R.R Kamath, V.K Shirva, P.S Vishwanathan
July-December 1986, 11(3):502-505
Full text not available  [PDF]
  208 69 -
The Influence Of Bolus Conductivity, Electrode And Phantom Sizes On The Rate Of Heating During RF Capacitive Hyperthermia
N.M.S Reddy, K.S Viswanathan, B.K Bhaskar, I.S Balakrishnan, V Shanta, S Krishnamurthi
July-December 1986, 11(3):397-400
Full text not available  [PDF]
  242 33 -
Dosimetric, Radiation Protection And Accessory Cost Aspects In Interstitial IR-192 Implants
S M Deore, D D Deshpande, M P Saple, A J Chaudhary, R Pandhi, K A Dinshaw
July-December 1986, 11(3):219-220
Full text not available  [PDF]
  235 36 -
Calibration Of Radiation Monitoring Instruments In Terms Of Dose Equivalent Units
P.N.M.R Vijayam, V.W Naik, A Kannan
July-December 1986, 11(3):547-550
Full text not available  [PDF]
  215 56 -
Estimation Of Radiation Dose From Iridium-192 Wire Handling In Brachytherapy
A Shanta, S.M Deore, S Ramaswamy, K.R Das
July-December 1986, 11(3):523-525
Full text not available  [PDF]
  241 28 -
Implementation Of An Integrated Treatment Planning System With CT-An Overview.
Anil Kumar Sharma, M Ravikumar, C V S Murthy, S L Keshava, R Ravichandran
July-December 1986, 11(3):99-101
Full text not available  [PDF]
  229 40 -
Quality Assurance Test Procedures Carried Out On A Newly Installed 4 Mv Accelerator
Gopalakrishna P G Kurup, T P Ramachandran, C A Davis
July-December 1986, 11(3):125-128
Full text not available  [PDF]
  218 51 -
Tissue Equivalent Phantom For Brachytherapy Sources Dosimetry
G Arcovito, A Piermattei
July-December 1986, 11(3):153-153
Full text not available  [PDF]
  219 47 -
Our Experience Of sr90 - Y90 Beta Ray Application For Treatment Of Keloids.
J S Avadhani, A C Deka, B C Deka, V K Sathiyanarayanan, K V Raghavaiah
July-December 1986, 11(3):230-232
Full text not available  [PDF]
  226 35 -
Ferrokinetic Studies In Certain Haematological Disorders With Special Reference To Compartmental Models
M M Gupta, E Werner, P Roth, U Bohnert
July-December 1986, 11(3):271-273
Full text not available  [PDF]
  223 38 -
Uniformity Of Dose Distribution In Interstitial Biplanar Implants
J M Paul, R F Koch, P C Philip, F R Khan
July-December 1986, 11(3):211-214
Full text not available  [PDF]
  238 21 -
Risk Assessment Of Medical Radiation Workers
R Sadagopan, P.H Pardasani, S.J Supe, P.H Patel
July-December 1986, 11(3):553-555
Full text not available  [PDF]
  228 31 -
CF -252 Radioisotope For Neutron Therapy Of Bulky Localized Tumours
Y Maruyama
July-December 1986, 11(3):158-161
Full text not available  [PDF]
  206 52 -
Clinical Physicist's Contribution To Better Radiotherapy Of Specific Patients
S Jayaraman
July-December 1986, 11(3):4-7
Full text not available  [PDF]
  218 39 -
The Status Of Medical Physics In The Federal Republic Of Germany
A.M Schmitt, A Kaul
July-December 1986, 11(3):420-423
Full text not available  [PDF]
  191 65 -
The Status Of Medical Physics In India
Xie Nan-Zhu
July-December 1986, 11(3):424-427
Full text not available  [PDF]
  212 44 -
Lymphocyte Status Of Cancer Cervix Cases And Its Suppression After Radiotherapy
T.M.R Panicker, K Jagadeesan
July-December 1986, 11(3):341-343
Full text not available  [PDF]
  219 36 -
Information Input For Embryo and Dosimetry Due To Internal Emitters
A R Reddy, S C Mehta
July-December 1986, 11(3):266-269
Full text not available  [PDF]
  214 40 -
Preventive Maintenance And Micro Repairs Of Teletherapy Units
A M Pendse, M P Saple, B N Vithal
July-December 1986, 11(3):53-55
Full text not available  [PDF]
  216 38 -
A Unique Approach To Intraoperative Radiotherapy With A Saturn Linear Accelerator
Ponnunni K Kartha
July-December 1986, 11(3):87-89
Full text not available  [PDF]
  226 28 -
Quantitative Measurements Of 99m-Technitium Glucoheptonate In Brain Tumors
R Ravichandran, V K Jain, B S Das
July-December 1986, 11(3):274-277
Full text not available  [PDF]
  202 49 -
Occupational Radiation Exposure During Medical Uses Of Ionising Radiation
N Selvaraj, M Leela Meenakshi
July-December 1986, 11(3):477-480
Full text not available  [PDF]
  206 45 -
2-Deoxy-Glucose Induced Modification In The Radiation Response Of Human Brain Tumors : An In Vitro Study On Organ Cultures.
B.S Dwarakanath, V.K Jain
July-December 1986, 11(3):382-385
Full text not available  [PDF]
  198 52 -
Precision And Accuracy Of TL Personnel Monitoring Dosimeters
P Ayappan, M Sethuraman
July-December 1986, 11(3):532-535
Full text not available  [PDF]
  210 40 -
Foreign Body Localisation - Scott's Method
A Thanumalayan, G Narayanan, S Govindarajan, R Sampath
July-December 1986, 11(3):259-260
Full text not available  [PDF]
  218 30 -
Biological And Biophysical Dosimetry Of Auger Emitters In Vivo : A Review
D V Rao, K S R Sastry, V B Hyjayatapu, R W Howell, G F Govelitz
July-December 1986, 11(3):262-265
Full text not available  [PDF]
  206 42 -
Calibration Of Brachytherapy Sources
V W Naik, P N M R Vijayam, A Kannan, P S Jadhavgaonkar
July-December 1986, 11(3):221-222
Full text not available  [PDF]
  206 42 -
Californium -252 In Brachythrerapy : Physical Aspects AND Treatment Planning
J L Beach, Y Maruyama
July-December 1986, 11(3):162-165
Full text not available  [PDF]
  217 31 -
Dose Specification And Associated Problems In Intracavitary Therapy
CAF Joslin, A Flynn
July-December 1986, 11(3):149-152
Full text not available  [PDF]
  205 42 -
Estimation Of Capture Gamma-Ray Doses In The Maze And At The Doorway Of A Medical Accelerator Treatment Room
I Uchida, Y Onai, T Tomaru, T Irifune
July-December 1986, 11(3):512-515
Full text not available  [PDF]
  211 36 -
Generation Of Isodose Curves For Any SSD By Computer Method
T Ganesh, G N S Prasad
July-December 1986, 11(3):113-116
Full text not available  [PDF]
  200 46 -
Role Of CT In Radiotherapy
Subhash C Sharma
July-December 1986, 11(3):134-137
Full text not available  [PDF]
  186 60 -
Computation Of Temperature Distributions Inside Tissues Heated By Interstitial Hyperthermia Systems
N.K Uzunoglu, K.S Nikita
July-December 1986, 11(3):405-407
Full text not available  [PDF]
  211 34 -
Some Uses Of Spectrum In Radiotherapy
V Rajagopal, Y Radhakrishnaiah, Sivasankar Kotne
July-December 1986, 11(3):106-109
Full text not available  [PDF]
  206 38 -
Status Of Radiation Protection In Medicine In sweden
R Walstam
July-December 1986, 11(3):551-551
Full text not available  [PDF]
  211 32 -
Film Dosimetry Of Small Electron Beams For Routine Radiotherapy Planning
Azam Niroomand-Rad, Michael T Gillin, Robert W Kline, Daniel F Grimm
July-December 1986, 11(3):77-78
Full text not available  [PDF]
  188 54 -
Entrance Skin Exposure Contributions From Conventional, Photofluorographic And Automatic (Large Film) Chest X-Ray Units In Kuwait
C.N Vasisht, Y,Y Pakir, S.D Al-Zenki
July-December 1986, 11(3):481-483
Full text not available  [PDF]
  208 34 -
Radiation Protection Aspects In Installation Of Diagnostic X-Ray Unit And Work Planning
M.T Somashekharaiah, B.S Ramesh
July-December 1986, 11(3):463-468
Full text not available  [PDF]
  158 84 -
Patient Dose Measurement And Quality Assurance Tests In X-Ray Diagnosis With A Novel 'Diamentor' Chamber And A Photodetector System
A Sankaran, V.S Fatki, R.S Gokarm
July-December 1986, 11(3):320-323
Full text not available  [PDF]
  188 53 -
Personnel Dosimeters For Measuring Leakage Radiations From Medical Electron Accelerators
T Tomaru, Y Onai, I Uchida, T Irifune
July-December 1986, 11(3):508-511
Full text not available  [PDF]
  204 36 -
Physical Aspects Of Total Body Irradiation
R Jayaraman, S Panneerselvan, A V Lakshmanan
July-December 1986, 11(3):20-23
Full text not available  [PDF]
  171 68 -
Quality Assurance In CT Scanning
S C Klevenhagen
July-December 1986, 11(3):233-233
Full text not available  [PDF]
  195 43 -
Quantitative CT with Special Reference To Bone Mineral Measurements
Gopala U Rao
July-December 1986, 11(3):234-237
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  209 29 -
Evaluation Of Various Methods Of Treatment Of Keloids - A Study Of Two Hundred Cases With Five Year Follow Up
Mohammad Ashraf Darzi, S K Kaul, S J Supe
July-December 1986, 11(3):227-229
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  170 67 -
NMR Imaging With O. I Tesla Resistive Magnet
T A Linuma, H Endo, H Ikehira, H Fukuda, Y Tateno
July-December 1986, 11(3):251-253
Full text not available  [PDF]
  194 42 -
Teaching Radiation Therapy Physics And Dosimetry Of Photon And Electron Beams-A Combined Approach
M Ali, Y Pipman
July-December 1986, 11(3):445-447
Full text not available  [PDF]
  176 60 -
Photohaemolysis Of Erythrocytes Due To Lasers And Photosensitizes
S Ganesan, V Masilamani, N.H.B Heganath, N Nandegopal, S Natarajan
July-December 1986, 11(3):353-356
Full text not available  [PDF]
  209 27 -
Performance Tests On A Newly Installed Telecobalt Unit
S B Naik, P S Viswanathan
July-December 1986, 11(3):57-58
Full text not available  [PDF]
  204 32 -
Regulatory Requirements For Setting Up Radiocommunoassay (RIA) Laboratories In India And Their Present Status
G Janakiraman, S.G Sawant, P Sethulakshmi, Kanta Chhokra
July-December 1986, 11(3):497-498
Full text not available  [PDF]
  201 33 -
Retrieval And Analysis Of Patient Data At The Treatment Planning Computer
A M Pendse, R N L Kulkarni, B Sequeira, R Pandhi, K A Dinshaw
July-December 1986, 11(3):130-132
Full text not available  [PDF]
  202 32 -
Standardisation of Caesium-137 sources used in Selectron Remote Afterloading System
T P Ramachandran, C A Davis, P G G Kurup
July-December 1986, 11(3):180-183
Full text not available  [PDF]
  204 29 -
Maintenance Problems In A Radiotherapy Unit - A 10 Years Experience
Usha Kasthuri, N Selvaraj, Leela M Meenakshi
July-December 1986, 11(3):117-119
Full text not available  [PDF]
  201 31 -
Interaction Of Leprosy Bacilli With The Immunoglobulin G Molecule And Its Role In Hansenology
Ravindra Kumar, M.M Bajaj, Binay Swaroop
July-December 1986, 11(3):452-455
Full text not available  [PDF]
  190 42 -
Study Of The TL Characteristics Of Lif (Mg, Cu) Phosphor For Its Use In Medical Physics
Bhuwan Chandra, S.S Shinde, R.C Bhatt
July-December 1986, 11(3):569-572
Full text not available  [PDF]
  195 37 -
Radiation Safety Status Of X-ray Installation In India
M.L Bhutani, K.K Sanu, A Sabuwala, V.K Shirva, V.K Bhargava
July-December 1986, 11(3):459-462
Full text not available  [PDF]
  197 34 -
Computerized Stereotactic Technique For Brain Isotope Implants
Debabrata Bhaduri, Ralph D Reymond
July-December 1986, 11(3):208-210
Full text not available  [PDF]
  198 33 -
TDF’s Equation For Low Dose Rate Permanent Implants Brachytherapy
M.K Gupta, G Rai
July-December 1986, 11(3):334-337
Full text not available  [PDF]
  197 33 -
Evaluation Of Cord Dose In The Treatment Of Head And Neck Cancers With Cobalt Beam Therapy
P K Jayalakshmi, N Selvaraj, S Savithri, Leela M Meenakshi
July-December 1986, 11(3):13-16
Full text not available  [PDF]
  194 35 -
A Study On Acute Injury Threshold Levels Of The Skin Of Yellow Race By Laser Light
Shi Hong-min, Li Ji-Shi, Li Zhao-Zhang, Ma Bao-Zhang, Wu Qing-Sheng
July-December 1986, 11(3):348-351
Full text not available  [PDF]
  206 22 -
Three Decades Of Progress In Medical Physics At Cancer Institute
A.V Lakshmanan, I.S Balakrishnan, K.S Viswanathan, R Jayaraman
July-December 1986, 11(3):431-434
Full text not available  [PDF]
  206 22 -
Monte Carlo Calculation Of Dose Distribution In The ICRU Spherical Phanton
S.K. Gupta, R.K Kher, S.J Supe
July-December 1986, 11(3):561-564
Full text not available  [PDF]
  184 44 -
Status Of The Radiotherapy Facilities And Medical Physics Applications In The Radiotherapy Practices In India
V.K Bhargava, M.L Bhutani, K.K Sanu
July-December 1986, 11(3):435-438
Full text not available  [PDF]
  175 52 -
The Centralized Medical Physics Facility For Community Hospitals
Anthony Chung-Bin, Lawrence Lanzl, Ponnunni Kartha, Subramania Jayaraman
July-December 1986, 11(3):428-430
Full text not available  [PDF]
  196 31 -
Modulation Repair And Fixation Of Radiation Induced DNA Damage By Energy Supply
Jain Viney
July-December 1986, 11(3):357-360
Full text not available  [PDF]
  195 32 -
Development Of A Semiconductor Diode Dosimeter For Exposure Control In Radiation Therapy Units
D Ranganathan
July-December 1986, 11(3):313-316
Full text not available  [PDF]
  191 36 -
Selective Tumour Targeting With Special Reference To Tumour Localising Agents
D K Hazra, A K Shukla, Y C Agarwal, P Narain
July-December 1986, 11(3):295-297
Full text not available  [PDF]
  201 26 -
Quantitation With A Gamma Camera
J W Haggith
July-December 1986, 11(3):282-284
Full text not available  [PDF]
  202 24 -
Detection Of Leakage Neutrons From Medical, Electron Accelerator Using TLD
A.S Pradhan, R.C Bhatt, S.J Supe
July-December 1986, 11(3):516-518
Full text not available  [PDF]
  180 46 -
Dosimetric Study For Rectum And Bladder During Intracavitary Applications
V Hema, Anil Kumar Sharma, S L Keshava, R Ravichandran, B K M Reddy
July-December 1986, 11(3):186-188
Full text not available  [PDF]
  191 33 -
The Studies In Cancer By Non-Invasive Techniques
Smauel Vinod Baskaran
July-December 1986, 11(3):255-258
Full text not available  [PDF]
  191 32 -
Experience With CT Treatment Planning System
D D Deshpande, A M Pendse, S M Doore, S Ramaswamy, R Pandhi, K A Dinshaw
July-December 1986, 11(3):96-98
Full text not available  [PDF]
  192 31 -
Multi Fractions In Radiotherapy : How Much We Have Achieved
N C Singhal, R L Mathur, O P Sharma, C S Sharma
July-December 1986, 11(3):63-66
Full text not available  [PDF]
  200 22 -
Out-Reach Screening For Carcinoma Cervix In Places Around Padhar A Rural Set-Up Hospital
Anand Vijay Kumar
July-December 1986, 11(3):205-207
Full text not available  [PDF]
  184 38 -
Manual Semiremote Afterloader For Intracavitary Applications
P Austen, V K Nelson, M K Mahajan, P A K Mohan
July-December 1986, 11(3):189-192
Full text not available  [PDF]
  199 23 -
Dosimetry For Selectron After-Loading Technique
V Murali, A V Lakshmanan
July-December 1986, 11(3):176-179
Full text not available  [PDF]
  187 33 -
Thermal Dose Distribution In Homogeneous And Heterogeneous Tissue Equivalent Phantoms
N Surendran, H.M.S Reddy, I.S Talakrishnan, A.V Lakshmanan
July-December 1986, 11(3):401-404
Full text not available  [PDF]
  181 38 -
Radiation Incidents In The Radiotherapy Departments Of Medical Institutions In India An-over View
H.A Sabuwalla, V.K Shirva, V.K Bhargava
July-December 1986, 11(3):499-501
Full text not available  [PDF]
  190 28 -
A Modified CRE Formula For Use In Brachytherapy
S Savithri, V Nagarajan, Leela M Meenakshi
July-December 1986, 11(3):193-196
Full text not available  [PDF]
  188 30 -
Detection Of Thyroidal Abnormalities Following Irradiation Of Head And Neck Region
A K Shukla, V K P Rohatgi, R N L Srivastava, D K Hazra, Y C Agarwal, T N Edoliya
July-December 1986, 11(3):67-68
Full text not available  [PDF]
  184 34 -
Radiation Therapy Of Oesophageal Cancer - A Preliminary Report
Nagraj G Ruilgol, Vijay Kulkarni, A R Mehta
July-December 1986, 11(3):73-76
Full text not available  [PDF]
  190 28 -
Quantification Of Dyskinetic Segments And Its Correlation with GEF In Suspected LV Aneurysm By Means Of Phase Amplitude Analysis
G N S Mahapatra, B K Das, A Mandal
July-December 1986, 11(3):278-281
Full text not available  [PDF]
  188 29 -
A Study Of Injury Threshold Of Argon Laser Radiation For Yellow Race Skin
Li Ji-Shi, Shi Hong-Hin
July-December 1986, 11(3):344-347
Full text not available  [PDF]
  194 23 -
TSD For Multiple Daily Fractionation Treatment Regimes Of Radiotherapy
S.J Supe, J.B Sasane, J.G.R Solomon, V Balasundaram, V Koteshwara Rao
July-December 1986, 11(3):331-333
Full text not available  [PDF]
  181 35 -
A Method For Computing And Verifying Adequate Lung Compensation In Total Body Photon Irradiation
Sherali G Hussein, Greg N Kennelly
July-December 1986, 11(3):439-442
Full text not available  [PDF]
  183 33 -
Status Of Dosimetry In Radiotherapy Centres In India
K D Pushpangadan, G Subrahmanian, A Kannan, V D Kadam
July-December 1986, 11(3):41-44
Full text not available  [PDF]
  178 37 -
Quality Assurance In Radiation Therapy
N Suntharalingam
July-December 1986, 11(3):592-593
Full text not available  [PDF]
  186 29 -
Database Of Photon Attenuation Cross Sections
K Satoh, M Maeno, K Furumoto, Y Harata, R Sakaino, R Shimura, T Katoh
July-December 1986, 11(3):577-580
Full text not available  [PDF]
  188 26 -
Dose Reference Points In Brachytherapy - A New Concept
V Nagarajan, S Savithri, Leela M Meenakshi
July-December 1986, 11(3):201-204
Full text not available  [PDF]
  166 48 -
Bone Marrow Transplanted Splenic Colonies Induced By WR-2721 And MPG In combination
D.K Srivastave
July-December 1986, 11(3):386-389
Full text not available  [PDF]
  183 28 -
Current Trends In High Energy Photon And Electron Beam Dosimetry
N Suntharalingam
July-December 1986, 11(3):588-589
Full text not available  [PDF]
  179 32 -
Estimation Of Some Corrections In Ali And DAC For Indian Conditions For Unsealed Radionuclides
G.N Shaikh, U.C Mishra, D Krishnan
July-December 1986, 11(3):540-542
Full text not available  [PDF]
  151 59 -
Clinical Dosimetry Of Narrow Electron And Photon Fields
V K P Kumar, L V Marcial, J M Galvin, G J D'Angio
July-December 1986, 11(3):79-82
Full text not available  [PDF]
  169 41 -
One Year Experience With Toshiba RCR-120 C-5 Cobalt Teletherapy Unit.
A A Chougule
July-December 1986, 11(3):49-52
Full text not available  [PDF]
  175 35 -
Quality Assurance Survey OF Diagnostic X-Ray Units
M.P Jain, N Lakshmipati
July-December 1986, 11(3):469-472
Full text not available  [PDF]
  149 57 -
Split Course Radiotherapy In The Management Of Oral Cavity
S.P Mishra, B Paul
July-December 1986, 11(3):377-380
Full text not available  [PDF]
  172 34 -
A Microprocessor Based Film Dosimeter Reader
H Mittal, R N L Das Sarma, K Aravindakshan, P Gangadharan
July-December 1986, 11(3):298-301
Full text not available  [PDF]
  178 27 -
Compact Rugged Solid State Film Scanning Densitometer System For Radiation Field Analyser
A Sankaran, A Narayanan
July-December 1986, 11(3):302-305
Full text not available  [PDF]
  165 40 -
Scinillation Monitor With Fast Response For Monitoring Around Diagnostic X-Ray Installations
V H Risbud, G Ramanathan, P Gangadharan
July-December 1986, 11(3):306-309
Full text not available  [PDF]
  165 40 -
A Study In The Reduction Of Skin Reaction By Use Of Lead-Glass Filter In The Treatment Of Cancer Cervix Patients BY Tele-Cobalt-60 Therapy
L J Singh, M S Agrawal
July-December 1986, 11(3):69-72
Full text not available  [PDF]
  163 42 -
"The Six P'S In Radiation Oncology"
Ponnunni K Kartha, Anthony Chung-Bin, R Frank
July-December 1986, 11(3):38-40
Full text not available  [PDF]
  172 32 -
Interlocking Device For The Immobilisation Of The Patient And Table Height Adjustment During Irradiation
N.P Saple, S.M Deoro, D.D Deshpande, A.M Pendse
July-December 1986, 11(3):317-319
Full text not available  [PDF]
  183 21 -
Uptake Of Sodium Selenite And Its Effect On DNA Synthesis In Skin Tumorigenesis
P.C Mangal, Neelan Gulati, Ravinder Meur
July-December 1986, 11(3):369-372
Full text not available  [PDF]
  171 31 -
Differential Responsiveness In Gene Mutation Induced By Chemical Mutagen And Radiation In Mice
D Bhattacharjee
July-December 1986, 11(3):361-364
Full text not available  [PDF]
  167 34 -
"Dosimetry Of 'Mantle' Field Irradiation"
K S Viswanathan, A V Lakshmanan
July-December 1986, 11(3):24-27
Full text not available  [PDF]
  164 36 -
Dosimetry Of Mixed Fields Of Neutrons And Gamma Rays Using Sensitised And Unsensitized Lif TLD - 700
A.S Pradhan, R.C Bhatt, J Rasoow
July-December 1986, 11(3):519-562
Full text not available  [PDF]
  166 34 -
Intercomparison Of Ionization And Chemical Dosimetry Techniques For Central Axis Depth-dose Measurements From Cosalt-60 Teletherapy Machines
B L Gupta, U R Kini, R M Bhat, U Madhvanath
July-December 1986, 11(3):28-31
Full text not available  [PDF]
  157 40 -
Common Physical Parameters Of Cancer Oesophagus - A Study Of 500 Cases
S.M Abbas, S.K. Kaul, W.H Andrabi, Madanji Bazaz
July-December 1986, 11(3):373-376
Full text not available  [PDF]
  168 29 -
The Status Of Medical Physics In U.S.A
Lawrence H Lanzl
July-December 1986, 11(3):585-585
Full text not available  [PDF]
  171 25 -
The Need For Radiological Science Teaching To Paramedical & Medical Students
Y Radhakrishnaiah, Sivasankar Kotne, V Rahagopal
July-December 1986, 11(3):443-444
Full text not available  [PDF]
  162 33 -
Modalities Of Radiotherapy For Develop Centre - Decision Criteria
W H Andrabi, S M Abbas, M A Bhat, S K Kaul
July-December 1986, 11(3):45-48
Full text not available  [PDF]
  164 30 -
Modified FBX Dosimeter - Early Experiences With Dosimeter And Clinical Measurements
Vithal J Raj Rose, R K Roul, A D Singh, C.A Jayachandran
July-December 1986, 11(3):32-35
Full text not available  [PDF]
  163 31 -
The Physics Of Electron Intraoperative Radiation Therapy
L R Lauzl, M Kao, A Sabbas
July-December 1986, 11(3):83-86
Full text not available  [PDF]
  167 26 -
Application of FBX Dosimetry In Radiotherapy
V Rajagopal, Y Radhakrishnaiah, Sivasankar Kotne
July-December 1986, 11(3):36-37
Full text not available  [PDF]
  159 33 -
Present Status Of Internal Dosimetry
A Kaul
July-December 1986, 11(3):591-591
Full text not available  [PDF]
  163 28 -
Status Of Medical Physics In The UK
B.L Reece
July-December 1986, 11(3):590-590
Full text not available  [PDF]
  160 30 -
A Unified Approach To Dose-Effect Relationships In Fractionated Radiotherapy
C.G Orton
July-December 1986, 11(3):328-330
Full text not available  [PDF]
  146 42 -
A Study On Reduction Of Surface Dose Due To Lead-Glass Filter In Cobalt-60 Teletherapy
M S Agrawal, L J Singh
July-December 1986, 11(3):17-19
Full text not available  [PDF]
  151 37 -
Alpha Response Of Some TL Materials
K.S Sharada
July-December 1986, 11(3):565-568
Full text not available  [PDF]
  161 26 -
DRP Secondary Standard Dosimeters A Field Performance Evaluation
M R Deokar, P Jacob, P Gangadharan
July-December 1986, 11(3):310-312
Full text not available  [PDF]
  157 29 -
Dosimetry Of Photon Therapy : Special Techniques For Special Problems
Stedeford Brian
July-December 1986, 11(3):138-141
Full text not available  [PDF]
  151 31 -
Estimate Of Life-Time Dose In Persons Exposed Occupationally To X-Rays In Poland
J Jankowski, J Liniecki, P Swiderski, J Glombinski
July-December 1986, 11(3):473-476
Full text not available  [PDF]
  153 29 -
Personnel Monitoring In Low-Level Radiation Laboratories
S Ranganathan, B.S Narasinga Rao
July-December 1986, 11(3):536-539
Full text not available  [PDF]
  155 22 -
Effect Of Anoxia On Cellular Uptake Of Drugs
V.V Deorukhakar, M.S.S Murthy
July-December 1986, 11(3):365-368
Full text not available  [PDF]
  155 21 -
Tumour Significant Dose For Brachytherapy
S J Supe
July-December 1986, 11(3):197-200
Full text not available  [PDF]
  136 33 -
Experience In The Use Of Microtrons For Radiation Therapy
Rune Halstam
July-December 1986, 11(3):581-584
Full text not available  [PDF]
  137 29 -
Gamma Radiation And Thermal Treatments For Improving Glow Curve Structure Of CaSo4 : Dy
J.K Srivastava, S.J Supe
July-December 1986, 11(3):573-576
Full text not available  [PDF]
  141 22 -
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