ABSTRACT
Objective:To explore the efficacy of fluorescent retroperitoneal lymph node dissection in the comprehensive treatment of lymph node recurrence after radical prostatectomy (RP).Methods:From January 2017 to December 2020, 25 patients with lymph node recurrence diagnosed by 68Ga-PSMA PET/CT after RP in our hospital were enrolled in this study. The patients were 67 (59-77) years old. The median PSA was 7.7 (0.5-12.6) ng/ml at lymph node recurrence, and was treated with androgen deprivation therapy (ADT), suggesting hormone-sensitive prostate cancer. Before recurrence, 4 cases were in T 2 stage, 17 cases in T 3, 4 cases in T 4, 10 cases in N 0, and 15 cases in N 1stage, 25 cases in M 0stage. 2 cases diagnosed as ISUP grade group <3, 9 cases in group 4, and 14 cases in group 5. The median time from radical resection to recurrence was 43 (27-56) months. All 25 cases were diagnosed as lymph node recurrence by 68Ga-PSMA PET/CT examination. Fluorescence retroperitoneal lymph node dissection was performed. Pelvic lymph nodes were detected in the dark field under the fluorescence mode, and positive lymph nodes were found. The white light mode was switched, and the lymph nodes were cleaned, and recorded. For metastatic lymph nodes indicated by preoperative PSMA PET/CT, routine dissection was performed regardless of whether the lymph nodes were fluorescently positive or not. The only routine examination was performed if there were no lymph nodes with fluorescently positive staining in other sites. Perioperative data, biochemical recurrence (BCR) rate, radiological recurrence (RAR) rate, and follow-up data were collected and analyzed. Results:25 patients were pathologically diagnosed with lymph node metastasis. The median lymph node dissection time was 21(15-28) min, estimated blood loss was 30(20-50) ml, hospital days was 4(3-5)d without any severe complications (<Clavien 2). Lymph node dissection and postoperative pathology: 25 cases were pathologically confirmed as lymph node metastasis. 43 lymph nodes of 25 cases were dissected, among which, 37 lymph nodes showed fluorescent positive, 32 lymph nodes were confirmed as metastatic pathologically. The median number of dissected lymph nodes was 2 (1-3). All 25 cases were followed up, with a median follow-up time of 27 (15-57) months. 24 cases achieved complete PSA response (PSA<0.2 ng/ml) in this study, of which 1 case developed BCR 6 months after surgery, and 1 case developed RAR 12 months after complete PSA response (ilium, PSA was 0.33 ng/ml). 1 case did not reach the PSA response and progressed to castration-resistant prostate cancer within 3 months after the operation.Conclusions:For patients diagnosed with lymph node recurrence by 68Ga-PSMA PET/CT examination, fluorescence imaging retroperitoneal lymph node dissection has a relatively small surgical range, few intraoperative complications and a low postoperative recurrence rate.