Radioisotope guided sentinel lymph node dissection in patients with localized prostate cancer: Results of the first 100 cases

Aims: The purpose of this prospective study was to assess the results and the relevance of radioisotope guided pelvic lymph node dissection (PLND) in loco-regional staging in patients with clinically localized prostate cancer. Methods: A total of 100 patients with prostate cancer underwent radioisotope guided PLND. Eighty-seven patients were candidates for retropubic radical prostatectomy and 13 underwent radiotherapy. The 72 first patients received 2x 0.3 ml of 30 MBq-nanocolloid-Tc-99m and the next 28 patients received 2x 0.3 ml of 100 MBq. Sentinel lymph nodes (SLNs) were detected intraoperatively with a gamma probe. Results: A median number of three SLNs was removed per patient. SLNs were located outside obturator fossa in more than two thirds of patients. Lymph node involvement was observed in 12% of patients. Fifty percent of the LNM were outside obturator fossa;41.6% of lymph node metastases (LNM) were lying at the first centimeters of the hypogastric artery. Eleven of the 13 LNM were detected in the SLN. The two non-SLN (NSLN) involved nodes were found in two patients who failed the sentinel lymph node procedure. Each of 12 patients had pre-operative PSA above 10 ng/ml and Gleason score >7. Conclusions: Limited PLND to obturator fossa is clearly insufficient for accurate lymph node staging in patients with prostate cancer. SLN procedure could be an alternative for pelvic lymph node staging with an excellent sensitivity in patients with unfavorable prognostic factors (PSA >10 ng/ml; biopsy Gleason score >6). (C) 2008 Elsevier Ltd. All rights reserved.