Current perspectives of sentinel lymph node dissection at the time of radical surgery for prostate cancer

Abstract

The sentinel lymph node dissection (SLND) concept relies on the accurate detection of primary nodal landing sites and could represent a major advancement towards accurate, non-invasive pelvic staging in prostate cancer (PCa). Different iterations of the technique have now been validated and reproduced mostly in large-volume centres. The existing evidence denotes the feasibility and sensitivity of SLND, with encouraging pre- and intraoperative detection rates of 98% and 96%. Yet, current surgical practice mandates a backup template dissection due to a false negative rate, up to 7.1%, of tracer-guided surgery. In practice, SLND failed to achieve nodal detection in up to 20% of pelvic sidewalls. Despite scarce validated evidence, current consensus mainly attributes these false negative cases to altered prostatic drainage secondary to malignant obliteration of lymphovascular structures. In parallel, multiple SLND studies have highlighted the complex and variable drainage pathways from the prostate, furthering the established anatomical atlases. The most promising approach may therefore rely in magnetic nanoparticles and PCa-targeting ligands. However, in the absence of a clear sentinel node or region for the prostate, formal SLND is difficult to integrate in routine surgical practice for now. As such, tracer-guided dissection is only used as a complementary intervention to highlight first- echelon nodes and aberrant lymphatic pathways found beyond the commonly adopted pelvic lymphadenectomy templates.

Current Imaging Techniques for Lymph Node Staging in Prostate Cancer: A Review

“…In a recent systematic review of SLN in PCa, the overall median pre-operative and intraoperative detection rates were 97.8 and 96.1%, respectively, with an overall median false negative rate of 7.1% (57).…”

Staging and tumor biological mechanisms of lymph node metastasis in invasive urinary bladder cancer

“…The mean sensitivity and specificity for detecting LN metastasis in each pelvic lymphatic station were 67% and 90%, respectively. These findings indicate that as UBC metastasis to pelvic LNs is difficult to predict accurately using the SNB technique, it has low clinical value SLNs for prostate cancer (185). In other systemic review, van der Zaag et al, showed that the overall sensitivity rate of SN mapping in patients with colorectal cancer was 70% (186).…”

“…The use of tracer that only delineates lymphatic drainage transforms the procedure into a radio-guided or fluorescence-guided dissection (185). The future of a true SN concept seems to depend on the identification of a cancer-specific targeted ligand which is bound to an intraoperatively detectable tracer…”

Advanced Nanotechnology Leading the Way to Multimodal Imaging‐Guided Precision Surgical Therapy

“…[49][50][51][52][53] SLNs are the first station that receives lymphatic drainage from the primary tumor and reflects the status of other DLNs. [57] The SLN biopsy with the gold standard method is not much in clinical settings due to the use of radiotracer, and novel radioisotope-free methods are expected. Traditional LN mapping techniques in clinical applications include radionuclide, blue dyes, and fluorescence imaging.…”