Radioisotope guided pelvic lymph node dissection for prostate cancer staging

Objectives: Pelvic lymph node metastases indicate a poor prognosis in prostate cancer. Despite improvements in modern imaging techniques, pelvic lymph node dissection is still the only reliable staging procedure. Recent data indicate an individual variability of lymphatic drainage of the prostate. Therefore the sentinel lymph node (SLN) concept has been introduced to improve the sensitivity of pelvic lymph node dissection. Methods: For preoperative localization of the SLN, a scintigraphy is performed after intraprostatic injection of a radiocolloid. Intraoperatively the SLN can be detected by means of a gamma probe. In addition to the standard dissection field, all lymph nodes, which have been identified as SLN by preoperative imaging and intraoperative gamma probe application, are dissected. Results: SLN can be identified with preoperative scintigraphy and intraoperative gamma probe detection. About 50% of SLN are found outside the obturator fossa in the region of the internal, external and common iliac artery, as well as presacrally. Limiting the extension of lymphadenectomy to the obturator fossa, a significant number of SLN would have been missed. Conclusions: Published data indicate the suitability of SLN dissection for prostate cancer staging. It can improve the sensitivity of pelvic lymph node dissection and helps to reduce the extent of surgery. (C) 2005 Elsevier B.V. All rights reserved.