ESTRO 2024 - Abstract Book

S375

Beachytherapy - Physics

ESTRO 2024

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Average Standard

value

=

0.06% 0.28%

deviation

=

Registered 4 — Registered values greater than 2% = 0 (not considering a single record in this category prior to the correction of a plan) — 95% confidence interval = [0.048% - 0.065%] — 99% confidence interval = [0.045% - 0.067%] — 99.9% confidence interval = [0.042% - 0.070%] Based on obtained confidence intervals, a bias of 0.06% can be established. This may be due to truncation carried out by the TPS when reporting the dose values with two digits after the comma. In any case, this value is well below the 15% tolerance limit established by the International Atomic Energy Agency (IAEA) and the 2% tolerance accepted at our center. In the case of one patient, it was possible to detect an error in the planning carried out by the TPS in a timely manner, and to amend it prior to treatment. This calculation was discarded from the plan since the error was corrected, and the new calculation was reported. values greater than 1% =

Conclusion:

The present work introduces and evaluates the preclinical efficacy of a double calculation tool designed for 2D HDR brachytherapy, which, being efficient and inexpensive, allows for the independent calculation of treatment doses determined by the TPS readily. Since the results obtained are significantly more reliable than international recommendations, this independent verification by the developed program provides a solid and simple basis for application in brachytherapy planning, and can feasibly be adopted by other radiotherapy centers.

Keywords: Planning, Independent calculation

References:

(1) Van Dyk, Jacob & Rosenwald, J.-C & Fraass, Benedick & Cramb, Jenna & Ionescu-Farca, F. & Sharpe, Michael. (2006). IAEA Technical Reports Series No. 430: Commissioning And Quality Assurance Of Computerized Planning Systems For Radiation Treatment Of Cancer. Medical Physics - MED PHYS. 33. 10.1118/1.2167371. (2) Fraass, B., Doppke, K., Hunt, M., Kutcher, G., Starkschall, G., Stern, R. and Van Dyke, J. (1998), American Association of Physicists in Medicine Radiation Therapy Committee Task Group 53: Quality assurance for clinical radiotherapy treatment planning. Med. Phys., 25: 1773-1829. https://doi.org/10.1118/1.598373 (3) Rivard, M.J., Coursey, B.M., DeWerd, L.A., Hanson, W.F., Saiful Huq, M., Ibbott, G.S., Mitch, M.G., Nath, R. and Williamson, J.F. (2004), Update of AAPM Task Group No. 43 Report: A revised AAPM protocol for brachytherapy dose calculations. Med. Phys., 31: 633-674. https://doi.org/10.1118/1.1646040 (4) Alfonso, R., Andreo, P., Brunetto, M., Castellanos, E., Jimenez, E., Venencia, D., & Silvestre, I. (2010). Physical aspects of radiotherapy quality assurance: quality control protocol - Update of IAEA TECDOC-1151 (IAEA-CN--182). International Atomic Energy Agency (IAEA)

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