Pd22-03 urinary Function Following High Dose Intensity Modulated Radiotherapy for Clinically Localized Prostate Cancer

Abstract

PSMA PET-imaging prior to SRT to that of a patient cohort which did not have PSMA PET-imaging before SRT.METHODS: We included 610 patients who underwent SRT, of whom 298 underwent a PSMA-PET/CT prior to SRT, and 312 did not. No additional hormonal therapy was prescribed. To compare both cohorts, case-control matching was performed, using the prostatespecific antigen (PSA)-value at initiation of SRT, pathological Grade Group, pathological T-stage, surgical margin status, and biochemical persistence after RARP as matching variables. Outcome variable was biochemical progression at one year after SRT, defined as either a rise of PSA !0.2 ng/mL above the nadir after SRT, or the start of additional treatment.RESULTS: After case-control matching, 216 patients were matched in both cohorts (108 patients per cohort). In the patient cohort without PSMA-PET/CT prior to SRT, 23/108 patients (21%) had biochemical progression of disease at one year after SRT, compared to 9/108 patients (8%) who underwent restaging PSMA-PET/CT prior to SRT (p[0.007).CONCLUSIONS: Patients who underwent restaging PSMA-PET/CT for BCR after RARP had better short-term oncological outcomes after SRT than those who underwent 'blind' SRT. Thus, PSMA-PET/CT is associated with an improved oncological outcome in a selected series of patients.