ESTRO 2025 - Abstract Book

S322

Brachytherapy - Physics

ESTRO 2025

Results: In Fig. you can get feeling graphically the value of dwell-positions fluctuations corresponding to 3 examined treatment afterloader setups. In the table you can see the measured dwell-positions of the radiation source in channel 2 of the Venezia26 brachytherapy applicators for different configurations and compare them with each other (Diff). The average fluctuation in the dwell-position was about ~0.35 mm, which is quite insignificant in comparison with 2 mm level. The maximum jump in the dwell-position was about ~1 mm.

Table. The coordinates (X,Y) and the mismatching (Diff) of measured dwell-positions of radiation source in Channel2 of Venezia22 brachytherapy applicator for different setups in all combinations (Direct-Right, Direct-Left, Right-Left). Conclusion: Using an accurate and fast 2D matrix method, it was found that different arrangements of afterloader relatively to the patient couch could cause source dwell-position variations of order ~0.35 mm, which is small, compared to the reference tolerance level of 2 mm.

Keywords: Applicator commissioning, 2D-array, dwell-position

References: V.Stserbakov. PTW OCTAVIUS Detector 1600 SRS is virtuous tool in commissioning of brachytherapy applicator. - Radiotherapy and Oncology Vol.194 S327 (2024). Poster 263, ESTRO in Glasgow (2024). https://www.youtube.com/watch?v=Msy9iLnA-JI&t=300s Russian version: https://www.youtube.com/watch?v=LRwCIfVYq9A&t=283s