Advances in sentinel node dissection in prostate cancer from a technical perspective.

Abstract

The most important feature of sentinel node biopsy for prostate cancer procedure is that staging can be improved. Sentinel nodes might be found outside the extended pelvic lymph node dissection template what renders the sentinel node additive of extended pelvic lymph node dissection. At the same time, staging within the template can be further refined. We reviewed the literature regarding the sentinel node biopsy procedure for prostate cancer. PubMed and Embase were searched for all English-language publications from January 1999 to September 2014 by using the keywords as "prostate cancer" and "sentinel lymph node" plus "biopsy" "dissection" and/or "procedure." The present review discusses step-by-step sentinel node biopsy for prostate cancer. Topics of discussion are: (i) preoperative sentinel node mapping (tracers and imaging); (ii) intraoperative sentinel node identification (surgical procedure and outcome); and (iii) novelties to improve sentinel node identification (pre- and intraoperative approaches). Conventional sentinel node mapping is carried out after the injection of a (99m) Tc-based tracer and subsequent preoperative imaging; for example, lymphoscintigraphy and single-photon emission computed tomography/computed tomography. This approach allowed the detection of sentinel nodes outside the extended lymph node dissection template in 3.6-36% of men with intermediate- and high-risk prostate cancer. Hereby, an overall false negative rate of sentinel nodes was reported between 0% and 24.4%. To further refine the intraoperative sampling procedure, novel imaging methods such as fluorescence imaging have been introduced. Prospective randomized comparison studies are required to confirm the added benefit of sentinel template directed nodal dissection. A proper and obtainable end-point of such a study could be the number of removed positive nodes for carrying out nodal dissection with or without sentinel template directed dissection. Similarly, the clinical impact of novel imaging technologies requires further investigation.