%A Pal, Surajit
%A Ravishankar, R
%A Sharma, R
%A Muthukrishnan, G
%A Ray, Dilip
%A Roy, S
%A Srivastava, D
%T Empirical formula for the prediction of off axis ratios and isodose curves for a treatment planning system
%9 Original Article
%D 2006
%J Journal of Medical Physics
%R 10.4103/0971-6203.29196
%P 262-268
%V 31
%N 4
%U https://www.jmp.org.in/article.asp?issn=0971-6203;year=2006;volume=31;issue=4;spage=262;epage=268;aulast=Pal
%8 October 1, 2006
%X A mathematical model has been developed for prediction of off axis ratio (OAR), using Wood - Saxon term used to represent nuclear potential. This method has been satisfactorily applied for predicting OAR in case of ^{60}Co γ -rays and high energy
X-rays. Investigations are considered upto a depth of 25 cm in the case of 4MV LINAC for which measurements were carried out in our laboratory using indigenously developed Radiation Field Analyzer. For 60Co γ-rays as well as 6 and 18MV LINAC beams we could get off-axis profiles only upto 20 cm. The shift δ between measured and predicted OAR is within ±2 mm except for 20 cm depth near the falling edge of the penumbra, where it is 2.80 mm. Software has been developed in Visual Basic 6 on Windows platform to plot Isodose curves, which is based on the mathematical modeling of OAR and central axis percentage depth dose.
%0 Journal Article
%I Wolters Kluwer Medknow Publications
%@ 0971-6203