ESTRO 2024 - Abstract Book

S2303

Clinical - Urology

ESTRO 2024

adjuvant/salvage postprostatectomy radiotherapy are 64 – 72 Gy in standard fractionation. But no one knows 72 Gy is better than 64 Gy. We need to consider who might be candidates for this 72 Gy boost threatment.

Material/Methods:

Ninety-four patients were retrospectively analyzed. As can be seen from the table, preoperative characteristics were as follows. Their average age was 65.4 years. The range was 45 to 80 years. Adjuvant radiotherapy was administered at a mean of 40.9 months (range, 2.0 - 200.9 months) postoperatively. Initial prostate-specific antigen (PSA) averaged 15.65 ng/ml (range 2.0 - 200.9 ng/ml). Pathological findings were as follows. The values for Gleason score (GS) 4, 5, 6, 7, and 8 were 3, 3, 5, 45, 16, and 22, respectively. The numbers of pathological T staging T1, T2, T3, and T4 were 1, 48, 40, and 3, and the numbers of low, intermediate, and high risk groups were 5, 13, and 76. Lymph node metastases (N+) 12, lymphovascular invasion (v+ or ly+) 59, perineural invasion (pn+) 67, extraprostatic extension positive (EPE+) 45, surgical margin positive (RM+) 41, seminal vesicle invasion (Sv+) 26. The radiation dose for the 10 patients was 66 Gy/33 fs /7 wks, the other 84 patients received an additional radiation boost of 6 Gy /3 fs according to MRI images and pathological findings.

Median follow-up months were 22.6 months (mean 35.9 months, range 1.0-102.8 months). Failure time was defined as the point at which adjuvant hormonal therapy was initiated after radiation.

Single and multivariate Cox proportional hazards modes were performed by RStudio.

Results:

Table shows the univariate Cox proportional hazard estimates (beta) in 95% intervals. The beta values of vorly, pn, Sv, and boost were highly significant (p-value < 0.05) and well proportional.