PSMA-Guided Surgery and Tissue-Resident T-Cell Profiling in Node-Positive Prostate Cancer

TACTIC-P is a single-center, prospective, single-arm study in 12 men with biopsy-proven prostate cancer and pelvic lymph-node uptake on preoperative PSMA PET, without bone or visceral metastases, who are scheduled for robot-assisted radical prostatectomy and extended pelvic lymph-node dissection. On the day of surgery, participants receive intravenous gallium-68 PSMA-11 followed by PET/CT and PSMA-radioguided surgery using a drop-in gamma probe. Resected prostate tumor, metastatic lymph-node tissue, and matched blood samples are used for high-dimensional immune profiling. The main goal is to determine whether functional pathogen-specific bystander tissue-resident T cells can be identified and quantitatively characterized in the primary tumor and/or metastatic lymph nodes. The study also evaluates immune features relevant to future personalized immunotherapy, the ability of PSMA-radioguided surgery to detect pathologically positive lymph nodes, and perioperative safety through 12 weeks after surgery.