ESTRO 2024 - Abstract Book

S373

Beachytherapy - Physics

ESTRO 2024

11. A. H. Kashani, C.-L. Chen, J. K. Gahm, F. Zheng, G. M. Richter, P. J. Rosenfeld, Y. Shi, and R. K. Wang, Optical coherence tomography angiography: a comprehensive review of current methods and clinical applications, Progress in retinal and eye research 60, 66–100 (2017). 12. G. Famulari, M.-A. Renaud, C. M. Poole, M. D. Evans, J. Seuntjens, and S. A. Enger, RapidBrachyMCTPS: a Monte Carlo-based treatment planning system for brachyther apy applications, Physics in Medicine & Biology 63, 175007 (2018).

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Development of an independent calculation program for plan verification in HDR brachytherapy

Franco La Paz 1 , Mariana Alberdi 1 , Karol Guzmán 1 , Jimena Juan 1 , Adriana Castaño 1 , Mariela Dalla Rosa 1 , Alejandro De Rosa 1 , Valentina Ferreira 1 , Carlos Vega 1 , Marcelo Torres 2 , Leandro Ricagni 2 , Gustavo Paolini 1 , Aldo Quarneti 1 , Federico Lorenzo 1,2 1 Centro Hospitalario Pereira Rossell, Radiation Oncology Department, Montevideo, Uruguay. 2 Hospital de Clínicas, Radiation Oncology Department, Montevideo, Uruguay

Purpose/Objective:

Brachytherapy allows the delivery of high doses in a precise, highly conformational and safe manner. With the advent of high dose-rate (HDR) brachytherapy, significant doses are administered in a matter of minutes, which necessitates systems of redundant verification. About 60% of errors reported in radiotherapy are due to a lack of adequate independent secondary verification of the treatment plan (1). The American Association of Physicists in Medicine (AAPM) has emphasized the cardinal importance of performing a second independent verification, in which each dose calculation algorithm is compared with either computer or manual calculations (2). The objective of this work is to present and validate a self-developed computer program whose function is to effectively carry out double calculation of the doses that would be administered at different points of interest for HDR brachytherapy. The results of independent calculations obtained through our program are compared against those produced by the HDRplus™ 3.0 Treatment Planning System (TPS), at a Cobalt-60 HDR brachytherapy center.

Material/Methods:

To perform the double calculation, a script was written in Python language that uses .CSV (comma separated values) format to record the coordinates and dwell times of the source and the coordinates of the points of interest for the calculation of the doses. From these, the program calculates the dose contribution of each stop to each point of interest based on the TG-43 protocol formalism (3).

The calculation steps are detailed below: