ESTRO 2024 - Abstract Book

S3452

Physics - Dose calculation algorithms

ESTRO 2024

use. Furthermore, the clinical evaluation indicated that rCT_NLs can be employed for contouring purpose. Therefore, 8-bit CTs represents a promising option for optimizing AI algorithms for synthetic CT generation. This study was supported by GR-2019-12370739.

Keywords: CT resampling, dose comparison, clinical quality

References:

[1] Biggs et al., (2022). PyMedPhys: A community effort to develop an open, Python-based standard library for medical physics applications. Journal of Open Source Software, 7(78), 4555, https://doi.org/10.21105/joss.04555

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Digital Poster

The Impact of Advanced Algorithms on the Treatment of Meningiomas

Carles Muñoz-Montplet 1,2,3 , Diego Jurado-Bruggeman 1,2 , Arantxa Eraso 4,2,3 , Rafael Fuentes-Raspall 4,2,3

1 Institut Català d’Oncologia, Medical Physics and Radiation Protection, Girona, Spain. 2 Girona Biomedical Research Institute (IDIBGI), Radiation Oncology and Medical Physics of Girona Group, Girona, Spain. 3 University of Girona, Department of Medical Sciences, Girona, Spain. 4 Institut Català d’Oncologia, Radiation Oncology, Girona, Spain

Purpose/Objective:

Radiotherapy planning considerations were initially developed for the previous calculation algorithms that yielded dose to water-in-water (Dw,w). Advanced algorithms have since been introduced to enhance accuracy, but their dose values, now in terms of dose to medium-in-medium (Dm,m) depend on the specific medium being considered. Notably, the approximately 4% lower values of Dm,m in bone can have significant clinical implications, especially when dose homogeneity is required. This study aims to show how mimicking Dw,w planning with Dm,m can introduce new issues in the treatment of meningiomas, particularly when they invade nearby bone tissue.

Material/Methods:

We selected ten patients with bone-invading meningiomas who were treated with radiotherapy at our institution. For each patient, we optimized an initial treatment plan to meet the clinical prescription objectives, which included PTV homogeneity, using the Eclipse TPS (version 15) and the Analytical Anisotropic Algorithm (AAA) convolution/superposition algorithm. We applied Photon Optimization algorithm and automatic intermediate dose in all cases.

Subsequently, we replicated the same procedure using the Acuros XB (AXB), an advanced algorithm also integrated into the Eclipse system, reporting Dm,m. AXB is based on the solution of the linear Boltzmann transport equation.