Laparoscopic sentinel lymph node (SLN) versus extensive pelvic dissection for clinically localized prostate carcinoma.

Purpose: Lymph node metastasis is an important prognostic factor in prostate cancer (PC). The aim of this prospective study was to evaluate the accuracy of sentinel lymph node (SLN) biopsy by laparoscopy in staging locoregional patients with clinically localized PC.
Methods: A transrectal ultrasound-guided injection of 0.3 ml/100 MBq (99m)Tc-sulphur rhenium colloid in each prostatic lobe was performed the day before surgery. Detection was performed intraoperatively with a laparoscopic probe (Gamma Sup CLERAD) followed by extensive resection. SLN counts were performed in vivo and confirmed ex vivo. Histological analysis was performed by haematoxylin-phloxine-saffron staining, followed by immunohistochemistry (IHC) if the SLN was free of metastasis.
Results: The study included 93 patients with PC at intermediate or high risk of lymph node metastases. The intraoperative detection rate was 93.5% (87/93). Nineteen patients had lymph node metastases, nine only in SLN. The false-negative rate was 10.5% (2/19). The internal iliac region was the primary metastatic site (43.3%). Metastatic sentinel nodes in the common iliac region beyond the ureteral junction were present in 13.3%. Limited or standard lymph node resection would have ignored 73.2 and 56.6% of lymph node metastases, respectively.
Conclusion: Laparoscopy is suitable for broad identification of SLN metastasis, and targeted resection of these lymph nodes significantly limits the risk of extended surgical resection whilst maintaining the accuracy of the information.