ESTRO 2023 - Abstract Book

S1950

Digital Posters

ESTRO 2023

Results For the described NRA system, the measured HVL is 0.5 mm Al. For the created radiation treatment plan with different dwell positions and times, the obtained 2D dose distribution across the NRA collimator is presented in Fig.2d as a mash map, and in Fig.2e as a dose profile along source motion showing 9% uniformity. Using the same plan, a reference dose measurement with PPIC gave the output at the surface of applicator to be 6.5 Gy/min, compared to 6.9 Gy/min when measured with EBT3 films.

Conclusion We presented Xoft NRA commissioning process. We described method to measure output and 2D dose distribution using the EBT3 based protocol, and the difference with the PPIC measured output was found to be 8%. When compared to the current applicator, NRA does not have flatting filter and source to surface distance is much shorter (11 vs. 20 mm). Consequently, design of NRA provides, besides the live target monitoring, higher output (6.5 vs. ~2 Gy/min) resulting in significantly shorter treatment times, providing better comfort of patient, and less possibility for movement during treatment.

PO-2167 Determining a universal reference plan geometry for high dose rate brachytherapy dosimetry audits

A. Dimitriadis 1 , K. Chelminski 1 , E. Granizo-Roman 1 , R. Abdulrahim 1 , G. Azangwe 1 , J. Swamidas 1