Cornea and Mantle shielding blocks were used to evaluate the dosimetry features of blocked beam radiotherapy. These blocks were used to produce the blocked beams for 5×5 cm2 and 30×30 cm2 field sizes. Doses were measured and calculated by the Clarkson's method and compared mutually. The variations of 0.05%, 0.92% and 0.99% were observed at three dose investigation points of 5×5 cm2 field size for cornea block. For mantle block the variation between measured and calculated values were found to be 1.97%, 2.46%, 2.39%, 2.13%, 2.00% and 1.93% at six dose investigation points of 30×30 cm2 field size. In this study dose calculated by the empirical relation using correction factors CijxK and CFi were found approximately equal to the experimental value. In the cases of both cornea and mantle shielding the calculated mean value of uncertainty in dose measurement between calculated dose values of Clarkson’s method and empirical relation was found satisfactorily to be within ±5.0%, fulfilling to the International Commission on Radiation Units and Measurements (ICRU) [1].
The Chittagong Univ. J. Sci. 40(1) : 47-58, 2018
Application of geometry correction factors for low-level waste package dose measurements. Revision 1