The lymphoscintigraphy is the standard of care for the detection of sentinel lymph nodes (SNs) and early staging of patients with breast cancer (BC) and cutaneous melanoma (CM). The aim of this work is to evaluate the usefulness of a portable gamma camera (Sentinella 102®) intraoperatively in patients undergoing to sentinel node biopsy (SNB).
We enrolled 47 patients (35 with BC and 12 with CM) who undergoing to SNB from October 2013 to January 2014 at the University Hospital of Bari. 35 patients with BC underwent to preoperative lymphoscintigraphy with 99mTc nanocolloid; planar images were acquired 30’ after the radiopharmaceutical injection using a dual-head gamma camera. These patients were submitted also to intraoperative scans, the day after radiopharmaceutical injection. In the surgery room, all the lymph nodes with a radioactive counting greater than 10% compared to the high radioactive SN have been removed. SNs were analyzed by OSNA method. 12 patients with CM underwent preoperative lymphoscintigraphy (the same day of surgery) with traditional gamma camera and SNs were also detected intra-operatively with Sentinella 102®. Sentinella 102® is a compact scintillation gamma-camera (crystal type: continuous CsI), with pinhole collimators.
Intraoperative scans with Sentinella 102® always correlated with traditional gamma camera images. In 4/47 patients, we saw a single hot spot with traditional gamma camera, but two contiguous SNs with Sentinella 102® (high spatial resolution). We identified 52 SNs in 47 patients with the traditional gamma camera, but 58 SNs intra-operatively with Sentinella 102®, therefore 6 additional SNs (10,3%) in 6 patients (4/6 patients with CM, 2/6 with BC). 5/6 of these SNs resulted negative for metastases; 1/6 SNs (patient with CM of the right arm and three axillary SNs) showed micrometastatic involvement. For this reason the patient was submitted to axillary lymphadenectomy but no other positive lymph nodes were found. The average time of intraoperatory device usage was 14 minutes (range: 10-21).
The portable gamma camera is useful in the surgical management of patients with BC and especially with CM, for different reasons: high spatial resolution, improvement of SNs detection and better distinguish them from the administration site, highlight areas of delayed drainage, check the complete excision of SNs, according to the literature data, excision of a greater number of SNs decreases the risk of false negativity. In our experience Sentinella 102® helps us to identify a greater number of SNs and one additional node was metastatic. Despite of the use of a portable gamma camera results in a longer time for the surgery and it is necessary to improve the anatomical orientation of acquired images, this device could be useful to reduce false negative rate.