ESTRO 2022 - Abstract Book

S1339

Abstract book

ESTRO 2022

Across all plots for AXB, jaw delineated field size has a slight difference when the ESS is changed from 1-1 to 0-0 with the smallest field size having the largest error. MLC delineated field size has a smaller error when a smaller DLG value of 0.030 is used for calculation. ESS of 1-1 also provides a more accurate calculation. MLC delineated field with DLG of 0.030 and ESS of 1-1 is then the better option for AXB calculation as compared to

others.

Conclusion Using MLC delineated field size provides a better dosimetric accuracy when modelling in the TPS for field sizes between 3x3 cm 2 and 1x0.5 cm 2 . For fields smaller than 1x0.5 cm 2 , dose calculation can be made more accurate using AXB calculation with ESS of 1-1 with a DLG of 0.030.