ESTRO 2024 - Abstract Book

S2399

Clinical - Urology

ESTRO 2024

This study aimed to evaluate the impact of various treatment-related factors on acute toxicity in patients with prostate cancer (PCa) undergoing salvage radiotherapy (SRT).

Material/Methods:

We extracted data from patients receiving SRT from a multicenter observational study. The analysis focused on the occurrence of Grade ≥ 2 and Grade ≥ 3 gastrointestinal (GI) and genitourinary (GU) acute toxicity. We examined several treatment-related parameters, including prophylactic nodal irradiation (PNI), hypofractionation, lymphadenectomy, radiation doses, techniques, image guidance, previous abdominal-pelvic surgery, adjuvant androgen deprivation therapy (ADT), and the type of ADT. Acute toxicity was assessed using the RTOG scale.

Results:

The study included 454 patients. The overall incidence of Grade ≥ 2 and ≥ 3 acute GI toxicity was 20.9% and 0.9%, respectively. For GU toxicity, the rates were 16.3% for Grade ≥ 2 and 0.7% for Grade ≥ 3. Patients receiving adjuvant ADT showed higher rates of Grade ≥ 2 GI toxicity (24.4% vs. 17.2%, p=0.046). However, no parameter was significantly associated with Grade ≥ 3 GI toxicity. Additionally, the rate of Grade ≥ 2 GU toxicity was higher in patients undergoing PNI (20.0% vs. 12.5%, p=0.024). For GU toxicity as well, no parameter was linked to Grade ≥ 3 toxicity.

Conclusion:

SRT was well-tolerated overall. The increased occurrence of intermediate-grade GU toxicity in patients undergoing PNI can be attributed to the higher bladder radiation dose in these cases. However, the reasons for the higher GI