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: 350  Home  EMail this page Print this page Decrease font size Default font size Increase font size 
ORIGINAL ARTICLE
Year : 2019  |  Volume : 44  |  Issue : 3  |  Page : 156-175

Out-of-field dose calculation by a commercial treatment planning system and comparison by monte carlo simulation for varian TrueBeam®


1 Department of Physics, Banasthali University, Jaipur, Rajasthan, India
2 Division of Radiation Physics, Regional Cancer Center, Thiruvananthapuram, Kerala, India
3 Department of Radiation Oncology, Aster Medcity, Kochi, Kerala, India

Correspondence Address:
Mr. N S Shine
“Shangri-La,” Alathara, Sreekariyam P.O., Thiruvananthapuram - 695 017, Kerala
India
Login to access the Email id

Source of Support: None, Conflict of Interest: None


DOI: 10.4103/jmp.JMP_82_18

Rights and Permissions

Purpose: The calculation accuracy of treatment planning systems (TPSs) drops drastically when the points outside the field edges are considered. The real accuracy of a TPS and linear accelerator (linac) combination for regions outside the field edge is a subject which demands more study. In this study, the accuracy of out-of-field dose calculated by a TPS, used with a TrueBeam® (TB) linac, is quantified. Materials and Methods: For dose calculation, Eclipse™ version 13.7 commissioned for TB machine was used. For comparison, Monte Carlo (MC) methods, as well as the measurements, were used. The VirtuaLinac, a Geant 4-based MC program which is offered as a cloud solution, is used for the generation of input phase-space (PS) files. This PS file was imported into PRIMO (PENELOPE based MC program) for the simulation of out-of-field dose. Results: In this study, the accuracy of the out-of-field dose calculated by a TPS for a TB linac was estimated. As per the results in comparison with MC simulations, the TPS underestimated the dose by around 45% on an average for the off-axis-distance range considered in this study. As the off-axis distance increased, the underestimation of the dose also increased. Conclusion: In this work, it was observed that the TPS underestimates doses beyond the edges of treatment fields for a clinical treatment executed on a TB machine. This indicates that the out-of-field dose from TPSs should only be used with a clear understanding of the inaccuracy of dose calculations beyond the edge of the field.


[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
    Viewed359    
    Printed14    
    Emailed0    
    PDF Downloaded31    
    Comments [Add]    

Recommend this journal