Journal of Medical Physics
TECHNICAL NOTE
Year
: 2013  |  Volume : 38  |  Issue : 3  |  Page : 139--142

Investigation on the effect of sharp phantom edges on point dose measurement during patient-specific dosimetry with Rapid Arc


RA Kinhikar1, VP Pandey1, Rojas K Jose1, U Mahantshetty2, DS Dhote3, DD Deshpande1, SK Shrivastava2 
1 Department of Medical Physics, Tata Memorial Hospital, Mumbai, India
2 Department of Radiation Oncology, Tata Memorial Hospital, Mumbai, India
3 Department of Electronics, Brijlal Biyani Science College, Amravati, Maharashtra, India

Correspondence Address:
R A Kinhikar
Department of Medical Physics, Tata Memorial Hospital, Parel - 400 012, Mumbai, Maharashtra
India

The objective of this work was to investigate and quantify the effect of sharp edges of the phantom on the point dose measurement during patient-specific dosimetry with Rapid Arc (RA). Ten patients with carcinoma of prostate were randomly selected for this dosimetric study. Rapid Arc plans were generated with 6 MV X-rays in the Eclipse (v 8.6.14) with single arc (clockwise). Dosimetry verification plans were generated for two phantoms (cylindrical and rectangular). The cylindrical phantom was solid water (diameter 34 cm) and the rectangular phantom was a water phantom (25 cm × 25 cm × 10 cm). These phantoms were pre-scanned in computed tomography (CT) machine with cylindrical ionization chamber (FC65) in place. The plans were delivered with Novalis Tx linear accelerator with 6 MV X-rays for both the phantoms separately. The measured dose was compared with the planned dose for both the phantoms. Mean percentage deviation between measured and planned doses was found to be 4.19 (SD 0.82) and 3.63 (SD 0.89) for cylindrical and rectangular phantoms, respectively. No significant dosimetric variation was found due to the geometry (sharp edges) of the phantom. The sharp edges of the phantom do not perturb the patient specific Rapid Arc dosimetry significantly.


How to cite this article:
Kinhikar R A, Pandey V P, Jose RK, Mahantshetty U, Dhote D S, Deshpande D D, Shrivastava S K. Investigation on the effect of sharp phantom edges on point dose measurement during patient-specific dosimetry with Rapid Arc.J Med Phys 2013;38:139-142


How to cite this URL:
Kinhikar R A, Pandey V P, Jose RK, Mahantshetty U, Dhote D S, Deshpande D D, Shrivastava S K. Investigation on the effect of sharp phantom edges on point dose measurement during patient-specific dosimetry with Rapid Arc. J Med Phys [serial online] 2013 [cited 2019 May 23 ];38:139-142
Available from: http://www.jmp.org.in/article.asp?issn=0971-6203;year=2013;volume=38;issue=3;spage=139;epage=142;aulast=Kinhikar;type=0