LAUSR

Metastatic disease at baseline was identified in 6/26 patients (5 in lymph nodes and bone, 1 in LN only) using standard conventional imaging. Neoadjuvant therapy was well-tolerated with 24/26 completing all 3 docetaxel cycles. All patients had multi-focal primary PC detected on pretreatment PSMA pelvic PET/MRI. All patients had a decline in SUVmax after treatment in at least one lesion, but resistant tumor foci on histopathology were noted in a subset of patients. All patients underwent planned surgery (24 robotic and 2 open RP). Mean OR time was 169 minutes and mean blood loss was 226 mL. Mean length of stay was 1.6 days (range 1-7). Grade 3-4 postoperative complications are seen in 7% (2/26). On final pathology, 10 patients had node positive disease, the rate of negative surgical margins was 73%, and 80% had pT3. No patient achieved a complete pathologic response. After follow-up of 9 months, the rate of BCR was 33.3%. CONCLUSIONS: Definitive surgery for high risk localized and/ or oligometastatic PC following neoadjuvant chemohormonal therapy generates a high rate of local tumor control. PSMA-based PET/MRI imaging showed a heterogeneity of tumor response which can potentially be used to monitor response and resistance during neoadjuvant treatment.