ESTRO 2025 - Abstract Book

S2668

Physics - Detectors, dose measurement and phantoms

ESTRO 2025

Results: When planning (see Figure 2b), the doses calculated at the positions where the films were located were: 206.33 ± 1.16 cGy (right), 207.00 ± 1.01 cGy (left), and 205.94 ± 0.96 cGy (anterior). Subsequently, measurements with radiochromic films, analyzed using the RIT software, yielded the following results: 214.48 ± 0.74 cGy (anterior), 217.08 ± 0.06 cGy (left), and 215.42 ± 2.34 cGy (right), as shown in Figure 2a. These results indicate that the Radixact effectively irradiates the surface of the Cheese Phantom with photons, without the need for a physical bolus.

Figure 2: a) Average doses with the respective standard deviation obtained from the RIT software. b) Dose-volume histogram obtained for the treatment used on the Cheese Phantom, orange corresponds to PTV and green to the virtual bolus used. Conclusion: Radixact X9 with RayStation is able to deliver the prescribed dose for a target volume located on the surface without physical bolus, which was verified by radiochromic film measurements. References: [1] Niroomand-Rad, A., Chiu-Tsao, S.-T., Grams, M.P., Lewis, D.F., Soares, C.G., Van Battum, L.J., Das, I.J., Trichter, S., Kissick, M.W., Massillon-JL, G., Alvarez, P.E. and Chan, M.F. (2020), Report of AAPM Task Group 235 Radiochromic Film Dosimetry: An Update to TG-55. Med. Phys., 47: 5986-6025. https://doi.org/10.1002/mp.14497 [2] Das, I.J. (Ed.). (2017). Radiochromic Film: Role and Applications in Radiation Dosimetry (1st ed.). CRC Press. https://doi.org/10.1201/9781315154879 [3] Moliner G, Izar F, Ferrand R, Bardies M, Ken S, Simon L. Virtual bolus for total body irradiation treated with helical tomotherapy. J Appl Clin Med Phys. 2015 Nov 8;16(6):164–176. doi: 10.1120/jacmp.v16i6.5580. PMID: 26699568; PMCID: PMC5691005. Keywords: In-vivo-dosimetry, skin irradiation, radixact

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Poster Discussion Towards proton range verification with phase-change nanodroplets and volumetric super-resolution ultrasound imaging Sophie V Heymans 1,2 , Marcus Ingram 1 , Bram Carlier 3,4 , Brecht Vandenborre 2 , Marc Fournelle 5 , Alessandro Ramalli 6 , François Rottenberg 7 , Edmond Sterpin 4 , Koen Van Den Abeele 2 , Jan D'hooge 1 1 Cardiovascular Sciences, KU Leuven, Leuven, Belgium. 2 Physics, KU Leuven, Kortrijk, Belgium. 3 Imaging and Pathology, KU Leuven, Leuven, Belgium. 4 Oncology, KU Leuven, Leuven, Belgium. 5 Imaging, Fraunhofer IBMT, Sankt