Comparative study of fluorescence vs. high-definition laparoscopy in extended pelvic lymph node dissection plus radical prostatectomy for patients with locally advanced prostate cancer

Abstract

Objective To compare the efficacy of extended pelvic lymph node dissection (ePLND) and oncological outcome by fluorescence laparoscopic radical prostatectomy(FLRP) versus high-definition laparoscopic radical prostatectomy (HD-LRP) for men with locally advanced prostate cancer(LAPCa). Methods In a prospective trial, we recruited 51 patients with T3a-bNxM0 prostate cancer from July 2015 to April 2018. Patients were assigned to study group or control group according to random number method, and were underwent either FLRP+ ePLND or HD-LRP+ ePLND. 21 in the study group were injected with 5 mg of indocyanine green (ICG) into the bilateral lobes of the prostate transperineally guiled by transrectal ultrasound 30 min before surgery for lymphography. During the surgical procedure a fluorescence laparoscope, optimized for detection in the near infrared range, was used to visualize the lymph nodes (green fluorescent) in the dissection region in the study group while a common laparoscopy introduced in control one. Lymph nodes were removed in the external iliac vessiles, internal iliac artery, obturator fossa regions, common iliac regions and presacral regions in both groups. Radical prostatectomy was completed in the both groups by similar steps. The operation time, blood loss, number of removed lymph nodes and positive lymph nodes, complication rate, biochemical recurrence (BCR) and metastasis free survival rates in 2 years were recorded and compared in the two groups. Results 51 eligible patients were selected, including 21 in the study group and 30 in the control group. The mean age of biopsy of study group and control one were (66.4±7.7)and (66.8±7.4), the mean age PSA(23.5±16.8)ng/ml and (26.0±20.1)ng/ml, the mean Gleason score of biopsy(8.1±1.0) and (7.9±0.9) respectively, and there was no statistical significant difference between two groups. The mean operation time of study group and control one were (45.9±4.6)min and (56.4±3.2)min, the mean removed lymph nodes were (27.7±5.6) and (22.1±5.6) respectively, and there was statistical significant difference between two groups(all P<0.05). Lymph nodes invasion in pathology were reported in 8 cases(38.1%)in the study groups while 9 (30.0 %) in the control one; the proportion of positive lymph node (metastasis) were 3.2%(19/583) and 3.4%(23/663) in the two groups respectively and no statistically significant difference was noted between the two groups. Lymphorrhagia occurred in 4 cases in the control group, and there was no serious complications in both groups. The median follow-up time was 20(7-33) month and during this time, BCR observed of 1(4.7%) in the study group and 8(26.7%) in the control; meanwhile, the MFSR was recorded of 100.0%(0)in the study group and 86.7%(4)in the control one, showing a statistically significant difference between the two groups(P=0.04). Conclusions Comparing with LRP, FLRP achieved better results of LN dissection, which will improve oncological outcomes. Key words: Prostate cancer; Extended pelvic lymph node dissection; Fluorescence laparoscopy; Indocyanine Green