ESTRO 2025 - Abstract Book

S1919

Clinical - Urology

ESTRO 2025

parameters in the Table 2. Almost all patients recieved preventive antiinflamatory and alpha-1 adrenergic receptor antagonist during treatment.

Results: With median follow up of 8,2 months (range from 0,23 to 16,2) the incidence of Grade 1, 2 and 3 acute GU toxicity was 55,6%, 7,4% and 3,7% respectively and Grade 1 and 2 acute GI toxicity was 9,3% and 3,7%. The main GU toxicity was dysuria, increase in frequency and nocturia. There was no Grade ≥ 4 toxicity. We didn’t find any dosimetry parameter or patient’s risk factor significantly associated with toxicity development. The only patient with G3 acute urinary retention at 6 months after SBRT has prostate volume more than 80 cm 3 and obstructive symptoms before treatment (Moderate IPSS score of 11). Conclusion: In our series prostate Eco guided Clarity© System SBRT without rectal spacer and urethral protection is associated with low incidence of acute GU and GI toxicity, comparable to the published data. Future investigation with more patients and longer follow up are needed..

Keywords: prostate cancer, SBRT, acute toxicity