Journal of Medical Physics
TECHNICAL NOTE
Year
: 2016  |  Volume : 41  |  Issue : 1  |  Page : 58--64

Comparison of two programs in calculating electron output factors at extended source-surface distances


Yunfei Hu, Jonathan Andrew Lambert, Yang Wang 
 Department of Medical Physics, Radiation Oncology Institute, Sydney and Gosford, Australia

Correspondence Address:
Yunfei Hu
41 William Street, Gosford, NSW 2250
Australia

Monitor units (MUs) calculated by radiotherapy treatment planning systems need to be verified independently. At extended source-surface distances (SSDs), different output factors (OFs) can be given by different independent MU checking packages due to the calculation methods used and assumptions made within them. The accuracy of two software packages - RadCalc® (LifeLine Software Inc., Austin, USA) and eDatabook (Y. Wang, Radiation Oncology Institute, Sydney, AUS) - was determined by comparing the calculated OFs directly to measured OFs for a series of standard electron cutouts on an Elekta Synergy linear accelerator at standard and extended SSDs (100 cm and above). For the majority of the measurements made, eDatabook provided OFs closer to the measured value than RadCalc; however, in two cases, eDatabook was unable to provide a factor. RadCalc failed to calculate the OFs accurately at extended SSDs as its calculation is based on the assumption that the established effective-SSD curve can accurately predict the data where there are no measurements available. The accuracy of eDatabook is due to its use of a linear interpolation to determine the OF at an extended SSD when there are no measurement data available.


How to cite this article:
Hu Y, Lambert JA, Wang Y. Comparison of two programs in calculating electron output factors at extended source-surface distances.J Med Phys 2016;41:58-64


How to cite this URL:
Hu Y, Lambert JA, Wang Y. Comparison of two programs in calculating electron output factors at extended source-surface distances. J Med Phys [serial online] 2016 [cited 2020 Feb 20 ];41:58-64
Available from: http://www.jmp.org.in/article.asp?issn=0971-6203;year=2016;volume=41;issue=1;spage=58;epage=64;aulast=Hu;type=0