ESTRO 2023 - Abstract Book

S1557

Digital Posters

ESTRO 2023

Acuros XB pre-release version 18. Dose verification of the results were performed by EBT-XD film measurements in a dedicated CIRS dynamic thorax phantom and compared to the original results, based on Acuros XB version 15.6 [1]. Results An improvement in dose prediction with the pre-released version 18 of Acuros XB, was seen compared to film measurements as shown in Table 2. Even for very small targets with diameters of 0.5cm a dose prediction accuracy around 5% or lower could be achieved, except for the smallest target s for 6MV.

Conclusion The new ELM model significantly improves the predicted dose for very small targets going from 23.7% to 9.5% and from 8.9% to 5.4% for the smallest targets for 6 and 10 MV, respectively, compared to results shown in previous work [1]. On average the ELM model is able to achieve dose accuracies of around 5% for both 6 and 10 MV. [1] Öllers MC, Swinnen ACC, Verhaegen F. Acuros® dose verification of ultrasmall lung lesions with EBT-XD film in a homogeneous and heterogeneous anthropomorphic phantom setup. Med Phys. 2020 Nov;47(11):5829-5837. doi: 10.1002/mp.14485