ESTRO 2024 - Abstract Book

S2386

Clinical - Urology

ESTRO 2024

duration and type, SRT fractionation and technique, image- guidance system, CTV to PTV margin, and EQD2α/β=1.5 to the prostate bed and pelvic nodes).

Results:

The analysis included 454 patients, and a summary of univariate findings is presented in Table 1. Five-year bRFS was significantly higher in patients treated with PNI compared to those without (58.3% vs. 35.1%, p<0.001). The multivariate analysis affirmed the favorable impact of PNI on both bRFS (HR: 0.44, 95%CI: 0.32-0.61, p<0.001) and DFS (HR: 0.49, 95%CI: 0.33-0.72, p<0.001). In addition, when compared to patients with ISUP grade 1, those with ISUP 3, 4, and 5 had significantly lower bRFS (HR: 2.37, 2.09, and 3.99, respectively, p<0.001). Similarly, subjects with pN1 stage exhibited lower bRFS compared to pN0 patients (HR: 1.91, p=0.001). Furthermore, among pN0 patients, the benefit of PNI on 5-year bRFS was evident across all ISUP grades: ISUP 1 (81.3% vs. 55.4%), ISUP 2 (66.5% vs. 50.2%), ISUP 3 (60.9% vs. 33.3%), ISUP 4 (71.5% vs. 35.4%), and ISUP 5 (43.0% vs. 9.5%).

Conclusion:

This study has demonstrated a significant benefit in terms of bRFS and DFS in PCa patients with biochemical recurrence treated with SRT, independent of various patient, tumor, and treatment-related factors. The advantages in bRFS were consistent across all ISUP grade groups.

Keywords: prostate cancer, nodal irradiation