PSMA PET-Guided Progression-Directed Radiotherapy for Oligoprogressive Prostate Cancer

PSMA-OLIGO-PRO is a multicenter ambispective observational real-world registry evaluating outcomes after PSMA PET-guided progression-directed radiotherapy for oligoprogressive prostate cancer. The registry includes retrospectively identified patients treated before June 26, 2026 and prospectively enrolled patients from June 26, 2026 onward. Eligible patients have metastatic hormone-sensitive or castration-resistant prostate cancer, are receiving active systemic therapy, and develop a limited number of new or regrowing lesions while the remaining disease sites are controlled. Oligoprogression is primarily defined by PSMA PET/CT or PSMA PET/MR, with MRI used when clinically appropriate, particularly for intraprostatic, local, or prostate-bed progression. Participants are not assigned to treatment by the registry protocol. All imaging, systemic therapy, radiotherapy modality, dose, fractionation, and follow-up decisions are made by treating physicians as part of routine clinical care. Progression-directed radiotherapy may include stereotactic body radiotherapy for nodal, bone, visceral, or local lesions, moderately hypofractionated external beam radiotherapy when clinically selected, and brachytherapy when appropriate for intraprostatic, prostate-bed, or selected metastatic oligoprogressive lesions. The registry evaluates whether treating all identifiable oligoprogressive lesions can delay escalation to a new systemic therapy line, preserve the oligometastatic state, maintain local control, and provide acceptable safety in contemporary PSMA PET-guided practice.