ESTRO 2024 - Abstract Book

S2366

Clinical - Urology

ESTRO 2024

Results:

50 consecutive PSMA-PET diagnosed metastatic PC patients underwent 1.5T MRgRT, among whom 31 synchronous OMPC patients were finally included. Patient characteristics are shown in Table. 1. All patients completed their planned MRgSBRT fractions (N=31x5=155) without interruption. The median fraction duration was 54 minutes (range: 27-100 minutes). Adapt-to-position (ATP) and adapt-to-shape (ATS) were conducted in 115 (74%) and 40 (26%) fractions. Besides 31 prostates, 64 metastatic LNs and 22 metastatic bones were also irradiated. The median follow-up duration was 22.8 months (range: 7.1-39.2 months). During the follow-up, all patients remained alive. Regarding toxicities, seven G2 adverse events were reported in 4 patients (4/31, 12.9%), among whom a sub-acute G3 neutropenia (at 4-month) was also scored in one patient. PSA was well controlled in 29 patients and progressed in only 2 patients (at 9-month and 15-month after MRgSBRT). PSMA-PET showed that irradiated targets were all resolved but new metastases were identified in these two PSA-progressed patients. The estimated OS, bPFS, and rPFS at 3-year (Figure. 1) were 100% (95%CI: 100%-100%), 92.2% (95%CI: 82.4%-100%), and 92.2% (95%CI: 82.4%- 100%), respectively.