Introduction

To validate the technique of selective sentinel node biopsy for staging intermediate to high-risk prostate cancer by comparing the technique with conventional extended lymphadenectomy (eLFD) in a prospective, longitudinal comparative study.

Methods

This study included 58 patients. With a Briganti score > 5% the procedure was performed in 54 patients at the time of laparoscopic radical and in 4 patients with biochemical relapse after radiotherapy as primary treatment. Multidisciplinary team consists of urologists and physicians of the nuclear medicine department. The day before surgery, all patients underwent trans-rectal ultrasound guided intraprostatic injection with the radioactive 99mTc nanocolloid under tracking of a portable gammacamara (Sentinella®) to avoid extraprostatic injection. Single-photon emission computed tomography (SPECT/CT) was performed one hour later. The next day we removed laparoscopically 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

Patients. SPECT/CT showed radiotracer deposits outside the eLFD territory in 72%(42/58) of the patients and the laparoscopic gamma probe in 60% (35/58). The mean number of active foci per patient was 4.3 in the SPECT/CT and 3.2 in the laparoscopic gamma probe. The lymph nodes were metastatic in 15 patients (25%), 15% (11/54) when the prostatectomy was the primary treatment and in 100% (4/4) of the radiotherapy group. In all cases with metastatic lymph nodes, there was at least one positive sentinel node (NPV 100%). The sentinel nodes were the unique nodes affected in 53% (8/15) Metastatic sentinel lymph nodes were found outside the eLFD territory in 3/15 patients (20%). The sensitivity was 100%, the specificity was 94.73%, the positive predictive value was 81.81%, and the negative predictive value was 100%._x000D_ _x000D_ Nodes. Total number of removed nodes was1289, total of removed sentinel nodes 295 and total of positive nodes 51. The mean number of removed nodes was 22 (9-41) and the mean number of sentinel lymph nodes was 5 (0-14). _x000D_

Conclusions

Sentinel node biopsy is superior to eLFD for diagnosing lymph node involvement during radical prostatectomy in intermediate and high risk prostate cancer patients. This technique can avoid eLFD when metastatic sentinel lymph nodes are not found (15 - 75% of patients), with the consequent functional advantages and cost saving properties.

Funding

NONE