Background: To examine the feasibility and safety of the SENSEI® drop-in gamma probe for robot-assisted, prostate-specific membrane antigen (PSMA)-radioguided salvage surgery (RGS) in lymph node or local oligorecurrent prostate cancer (PCa), detected via PSMA positron emission tomography/computed tomography (PET/CT). This evidence concerns the gene FOLH1 and prostate carcinoma.