[PSMA-Radioguided Surgery for Salvage Lymphadenectomy in Recurrent Prostate Cancer]

Recently, the use of ¹¹¹In-labeled PSMA-I&T-based radioguided surgery (¹¹¹In-PSMA^-RGS) for salvage surgery using intraoperative ex-vivo γ-probe measurements has been described by our group as a promising new and individual treatment concept in patients with localised recurrent prostate cancer (PC). ¹¹¹In-PSMA-RGS allowed for the intraoperative identification of metastatic lesions with a sensitivity, specificity and accuracy of 92.3, 93.5 and 93.1%, respectively, compared to histopathology. ¹¹¹In-PSMA-RGS was able to detect 5 additional lymph node metastases in 3 out of 31 patients compared to ⁶⁸Ga-HBED-CC-PSMA PET. A PSA decline >50 and >90% was observed in 24/31 patients and 17/31 patients, respectively. In 19/31 patients even a complete biochemical response was observed. 10/31 patients received further PC-specific treatment after a median of 125 days following ¹¹¹In-PSMA-RGS. Surgery-related complications were observed in 10 patients (Clavien-Dindo classification: grade 1 n=6, grade 3b n=4). ¹¹¹In-PSMA-RGS seems to be highly valuable for the intraoperative detection of small metastatic lesions in PC patients scheduled for salvage lymphadenectomy. It allows for an exact localisation and resection of metastatic tissue during ¹¹¹In-PSMA-RGS and thus is anticipated to have a beneficial influence on further disease progression. However, the identification of suitable patients on the basis of ⁶⁸Ga-PSMA PET imaging and clinical parameters is critical to obtain satisfactory results.