Novel technology of molecular radio-guidance for lymph node dissection in recurrent prostate cancer by PSMA-ligands

Purpose: Recently, prostate-specific membrane antigen-radioguided surgery (PSMA-RGS) has been introduced as a promising new and individual treatment concept in patients with localised recurrent prostate cancer (PC). In the following, we want to review our experience with PSMA-RGS in patients with localised biochemical recurrent PC. Methods: A non-systematic review of the literature was carried out with focus on technical and logistical aspects of PSMA-RGS. Furthermore, published data on intraoperative detection of metastatic lesions compared to preoperative PSMA-PET and postoperative histopathology, postoperative complications as well as oncological follow-up data are summarized. Finally, relevant aspects on prerequisites for PSMA-RGS, patient selection, and the potential benefit of additional salvage radiotherapy or potential future applications of robotic PSMA-RGS with drop-in γ-probes are discussed. Results: First results show that PSMA-RGS is very sensitive and specific in tracking suspicious lesions intraoperatively. Prerequisite for patient selection and localisation of tumour recurrence is a positive Ga-HBED-CC PSMA positron-emission tomography (PET) scan with preferably only singular soft tissue or lymph node recurrence after primary treatment. Furthermore, PSMA-RGS has the potential to positively influence oncological outcome. Conclusions: PSMA-RGS seems to be of high value in patients with localised PC recurrence for exact localisation and resection of oftentimes small metastatic lesions using intraoperative and ex vivo γ-probe measurements. However, patient identification on the basis of Ga-HBED-CC-PSMA PET imaging as well as clinical parameters is crucial to obtain satisfactory results.