Reliability of sentinel node procedure for lymph node staging in prostate cancer patients at high risk for lymph node involvement

Abstract

Aim. To investigate the reliability of a sentinel node (SN) procedure for nodal staging in prostate cancer (PCa) patients at high risk for lymph node (LN) involvement.

Material and methods. Seventy-four patients with localized prostate adenocarcinoma, who were clinically node-negative and had a risk of LN involvement of ≥ 10% (Partin tables), were prospectively enrolled. Upon intraprostatic 99mTc-nanocolloid injection, they underwent planar scintigraphy and SPECT imaging. Surgical removal of the SN, located by means of a gamma probe, was completed with a superextended LN dissection (seLND) as a reference and followed by radical prostatectomy.

Results. In total, 470 SN (median 6, IQR 3–9) were scintigraphically detected of which 371 (median 4, IQR 2–6) were located by gamma probe and selectively removed during surgery (79%). Histopathology confirmed LN metastases in 37 patients (50%) having 106 affected LN in total (median number per patient 2, IQR 1–4). Twenty-eight patients were node positive (N+) based on the analysis of the resected SN. However, the seLND that was performed as a reference revealed nine additional N+ patients resulting in a sensitivity of 76% (28/37). In total, 15 of 37 patients (41%) had metastases in SN only and could have been spared seLND to remove all affected nodes.

Conclusion. We found a relatively low sensitivity when addressing the SN procedure for nodal staging in PCa patients at high risk for LN involvement. Importantly, only less than half of the N+ patients could have been spared a seLND to remove all affected lymphoid tissue.