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.