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

Abstract

Abbreviations & Acronyms ePLND = extended pelvic lymph node dissection FN = false negative ICG = indocyanine green LN = lymph node MRI = magnetic resonance imaging NIR = near-infrared NR = not reported PCa = prostate cancer PET = positron emission tomography PLND = pelvic lymph node dissection SN = sentinel node SPECT-CT = single-photon emission computed tomography combined with computed tomography TRUS = transrectal ultrasound 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 Englishlanguage 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 singlephoton 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.

Lymph node staging in prostate cancer: perspective for the pathologist

“…Since then a number of studies have investigated the utility of SLN mapping to guide PLND in prostate cancer and potentially reduce the extent of dissection, although the procedure is regarded as experimental at this stage 1 24. A recent review of the literature reported that SLNs were identified outside of the dissection template for an extended PLND in 4.1–25% of cases, and of patients with positive LNs 3.5–17% had SLN metastases outside of the extended PLND field 25. These findings highlight the potential for SLN mapping to improve nodal staging.…”

New technologies in radioguided surgery in complex anatomic areas

“…The median overall detection rate (C1 SLN in a patient) was 98.6 % for SPECT/CT and 85.3 % for planar scintigraphic imaging [28]. The role of preoperative 3D imaging in the most common cancer in men, prostate cancer, was recently summarized by Acar et al [29]. The detection rate of SPECT/CT ranged from 95.6 to 100 %, with the advantages of 3D imaging being most prominent in obese patients [29].…”

“…The role of preoperative 3D imaging in the most common cancer in men, prostate cancer, was recently summarized by Acar et al [29]. The detection rate of SPECT/CT ranged from 95.6 to 100 %, with the advantages of 3D imaging being most prominent in obese patients [29]. In a cohort of 46 patients with prostate cancer, Vermeeren et al reported that 44 % of metastatic SLNs were detected only by SPECT/CT, and not by planar imaging [30].…”

“…Govers et al demonstrated in a meta-analysis that a combination of blue dye and radiocolloids does not improve the sensitivity in OSCC [74]. Blue dye may also blur the surgical field and hinder the resection of urogenital cancers [29,45]. As an alternative for optical imaging, the near-infrared (NIR) fluorescence tracer indocyanine green (ICG) was introduced by Motomura et al in 1999 [75].…”

Laparoscopic sentinel lymph node dissection in prostate cancer patients: the additional value depends on preoperative data

“…Is it possible to reduce further the percentage of LNI missing patients? The sentinel lymph node (SLN) technique, which assumes that the pathologic status of the SLN reflects the status of other pathologic regional lymph nodes, appears to be clinically robust in PC patients [10]. Nevertheless, the potential role of this technique in the decision tree to support prostate cancer patients is not yet well defined.…”