The sentinel node with technetium-99m for prostate cancer. A safe and mature new gold standard?

Background: The objective was to carry out a prospective study to compare the current extended pelvic lymph node dissection (ePLND) to the sentinel node (SN) technique with ^99mTcnanocolloid.

Methods: We conducted a prospective study between January 2013 and May 2020. In the first 74 patients, ^99mTc-nanocolloid was used. Then from June 2017 onwards, in 38 patients we used a combined radiotracer prepared by adding indocyanine green (ICG). A preoperative SPECT/CT was also performed to check on the SNs. We extracted the SNs guided by a laparoscopic gamma-ray detection probe and/or a fluorescence camera.

Results: We included 112 patients with a Briganti nomogram-assessed risk of 5% or more. In 4 out of the total, the radiotracer did not migrate. The mean number of extracted nodes was 21.56 (13.46-29.71) and the mean of extracted SNs was 5.17 (1.83-8.51) (P<0.001). The technique that registered the most nodes with high activity was SPECT/CT, with an average of 4.33 nodes (2.42-6.23) (P<0.001). We found SNs outside the template in 78% of the patients. A total of 46% of the complications were related to ePLND. The SN biopsy showed a sensitivity of 100%, specificity of 97.5%, PVV of 92.86%, and NPV of 100%.

Conclusions: Our results prove that ePLND is a technique with significant morbidity; up to 46% of the complications were related to the ePLND. The SN surgery showed great accuracy in detecting metastases due to the SPECT/CT and a lower rate of complications than ePLND.