Beyond the Briganti nomogram: Individualisation of lymphadenectomy using selective sentinel node biopsy during radical prostatectomy for prostate cancer.

Abstract Objective To validate the technique of selective sentinel node biopsy for diagnosing and staging intermediate to high-risk prostate cancer by comparing the technique with conventional extended lymphadenectomy (eLFD) in a prospective, longitudinal comparative study. Methods We applied the technique to 45 patients. After an intraprostatic injection of 99m Tc-nanocolloid and preoperative single-photon emission computed tomography (SPECT/CT), we extracted the sentinel lymph nodes, guided by a portable Sentinella® gamma camera and a laparoscopic gamma-ray detection probe. The eLFD was completed to establish the negative predictive value of the technique. Results SPECT/CT showed radiotracer deposits outside the eLFD territory in 73% of the patients and the laparoscopic gamma probe in 60%. The mean number of active foci per patient was 4.3 in the SPECT/CT and 3.2 in the laparoscopic gamma probe. The mean number of extracted sentinel lymph nodes was 4.3 (0–14), with 26% outside the eLFD territory. The lymph nodes were metastatic in 10 patients (22%), 6/40 (15%) when the prostatectomy was the primary treatment. In all cases with metastatic lymph nodes, there was at least one positive sentinel node. Metastatic sentinel lymph nodes were found outside the eLFD territory in 3/10 patients (30%). The sensitivity was 100%, the specificity was 94.73%, the positive predictive value was 81.81%, and the negative predictive value was 100%. Conclusion Selective sentinel node biopsy is superior to eLFD for diagnosing lymph node involvement and can avoid eLFD when metastatic sentinel lymph nodes are not found (85%), with the consequent functional advantages.