Journal of Medical Physics
 Home | Search | Ahead of print | Current Issue | Archives | Instructions | Subscription | Login  The official journal of Association of Medical Physicists of India      
 Users online: 598  Home  EMail this page Print this page Decrease font size Default font size Increase font size 
TECHNICAL NOTE
Year : 2011  |  Volume : 36  |  Issue : 3  |  Page : 176-180

Dosimetric analysis of beam-matching procedure of two similar linear accelerators


1 Department of Radiation Oncology, Ruby Hall Clinic, Pune, India
2 Siemens Ltd., HealthCare sector, Pune, India

Correspondence Address:
Janhavi R Bhangle
Department of Radiation Oncology, Ruby Hall Clinic, 40, Sassoon Road, Pune-411 001, Maharashtra
India
Login to access the Email id

Source of Support: None, Conflict of Interest: None


DOI: 10.4103/0971-6203.83497

Rights and Permissions

Linear accelerators from the same vendor in a radiation therapy center are usually beam-matched following Vendor's acceptance criteria. This protocol is limited to check the difference at particular points on the ionization curve for depth dose or beam profiles. This article describes different tests done after commissioning to evaluate the level of agreement between matched beams of two ONCOR Impression plus linear accelerators from Siemens. Total scatter factors, collimator scatter factors, wedge transmission factors were measured in water for 6-MV photon. All these factors for ONCOR2 were within ±1% of those values for ONCOR1. Along with these point dose measurements we have essentially used γ-index to compare the planar dose distribution from two beam-matched accelerators. For this study a set of ready packed EDR2 films was exposed on both accelerators. The set consisted of films for percentage depth dose, beam profiles, a pyramid shape, multileaf collimator's positional and dose delivery accuracy, and a film to compare head scatter at tray level. To include treatment planning system calculations, a film kept in axial plane was exposed to 3DCRT and IMRT plans with actual gantry angles and monitor units. These films were analyzed for γ in OmniPro IMRT software using different combinations of ∆dose and - ∆distances. All these films have shown good agreement for - ∆distance of 3 mm and ∆dose of 3 %.


[FULL TEXT] [PDF]*
Print this article     Email this article
 Next article
 Previous article
 Table of Contents

 Similar in PUBMED
   Search Pubmed for
   Search in Google Scholar for
 Related articles
 Citation Manager
 Access Statistics
 Reader Comments
 Email Alert *
 Add to My List *
 * Requires registration (Free)
 

 Article Access Statistics
    Viewed2350    
    Printed106    
    Emailed0    
    PDF Downloaded120    
    Comments [Add]    

Recommend this journal