ESTRO 2025 - Abstract Book

S390

Brachytherapy - Urology

ESTRO 2025

Overall median PTV D90 and GTV D90 (range) were 113,63% (80,6-170,57) and 136,45% (94,6-221,63) of prescription dose, respectively. Median urethra D10% revealed 103% (25,15-148,4). In LDR patients, median rectum D2cc was 70,16 Gy (25,89-111,4). In HDR patients, median rectum D10% was 64,9% (27,32-73,14). No acute toxicity grade >3 was observed. GI toxicity was absent in 82% of patients, while 16.4% and 1.6% experienced acute grade 1 and 2 GI toxicity, respectively. For acute GU toxicity, these percentages were 36.1%, 44.3% and 19.7%, respectively. 48 patients were evaluated for late toxicity. Amongst them, 81.3% had no late GI toxicity, while 12.5% and 6.3% experienced late grade 1 and 2 GI toxicity, respectively. For late GU toxicity, these percentages were 39.6%, 39.6% and 18.8%, respectively. One patient (2.1%) experienced late grade 3 GU toxicity, requiring TURP. 55 patients were included for PSA analysis. 74,5% of these remained biochemical recurrence-free, while 25.5% recurred (nadir +2 ng/ml) after a median time of 14 months.

Conclusion: Based on the presented data, focal salvage BT is deemed safe and effective in previously irradiated patients with locally recurrent PC. Longer follow-up is needed to confirm these results.

Keywords: Salvage brachytherapy, prostate cancer, toxicity

References: 1. Vanneste BG et al. Biomed Res Int . 2016; doi:10.1155/2016/6829875 2. Liu W et al. International journal of radiation oncology, biology, physics . Mar 1 2020; doi:10.1016/j.ijrobp.2019.11.001 3. Raman S et al. International journal of radiation oncology, biology, physics . Apr 1 2022; doi:10.1016/j.ijrobp.2021.12.164

4. Rousseau E et al. J Nucl Med . Nov 2019; doi:10.2967/jnumed.119.226381 5. Tran H, et al. Urol Oncol . Jul 2014; doi:10.1016/j.urolonc.2013.12.014 6. Tisseverasinghe SA et al. Transl Androl Urol . Jun 2018; doi:10.21037/tau.2018.05.09 7. Opbroek T et al. J Contemp Brachytherapy . Apr 2023; doi:10.5114/jcb.2023.126051 8. Cornford P et al. Eur Urol . Feb 2021; doi:10.1016/j.eururo.2020.09.046

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Digital Poster Brachytherapy as monotherapy in prostate cancer. Long term outcomes and predictive value of nadir PSA. The role of artificial intelligence. SILVIA RODRIGUEZ VILLALBA 1 , Jose Domingo Lago Martin 1,2 , Diana Guevara Barrera 1 , Jose Pérez-Calatayud 1,3 , Manuel Santos Ortega 1