An Experimental Dosimetry of Irregularly Shaped Fields Using Therapeutic Planning Computer

Kwon,  Hyoung Cheol; Oh,  Yoon Kyeong; Yoon,  Sei Chul; Bahk,  Young Whee

J Korean Soc Ther Radiol > Volume 2(2); 1984 > Article

Original Article

Journal of the Korean Society for Therapeutic Radiology 1984;2(2): 281-285.

An Experimental Dosimetry of Irregularly Shaped Fields Using Therapeutic Planning Computer

Hyoung Cheol Kwon, Yoon Kyeong Oh, Sei Chul Yoon, Young Whee Bahk

Section of Therapeutic radiology, Catholic Medical College, Korea.

ABSTRACT

The authors have intended to measure intrinsic dose distribution by Farmer dosimeter in irregularly shaped fields such as L.M. and T shape models in order to determine dose in homogeneity in those models. We made 2 off-xis points in each model and measured the depth dose at 1.5, 5 and 9cm below surface. The results showed 1~3% dose discrepancy between 2 points. We also measured the depth dose by geometric approximation and computer calculation in those models, and came to the conclusion that computer calculation using Clarkson's principle is simpler and the measurements are closer to the ideal data obtained by the experiment in three models of irregularly shaped fields than those of geometric approximation method.