Intraoperative radioguidance with a portable gamma camera: a novel technique for laparoscopic sentinel node localisation in urological malignancies.

ABSTRACT

PURPOSE: Our aim was to assess the feasibility of intraoperative radioguidance with a portable gamma camera during laparoscopic sentinel node (SN) procedures in urological malignancies. METHODS: We evaluated the use of the intraoperative portable gamma camera in 20 patients 16 patients with prostate carcinoma (PCC), 2 patients with renal cell carcinoma (RC) and 2 patients with testicular cancer (TC). Intra/peritumoural injection of (99m)Tc-nanocolloid ((99m)Tc) was followed by planar lymphoscintigraphy, SPECT/CT and marking of SN levels. Before laparoscopy a (125)I seed was fixed on the laparoscopic gamma probe as a pointer of SN seeking. The portable gamma camera was set to display the (99m)Tc signal for SN localisation and the (125)I signal for SN seeking. Matching of these signals on screen indicated exact SN localisation, and consequently this SN was removed. RESULTS: The mean injected dose was 218 MBq in PCC, 228 MBq in RC and 88 MBq in TC. Pelvic SN were visualised in all PCC patients, with uncommonly located SN in seven patients. SN metastases were found in seven patients (one in a uncommonly located SN). Both RC patients and TC patients had para-aortic SN, which were all tumour free. A total of 59 SN were removed. The portable gamma camera enabled real-time SN display/identification in 18 patients (90%). CONCLUSION: The use of a portable gamma camera in combination with a laparoscopic gamma probe incorporates intraoperative real-time imaging with improved SN identification in urological malignancies. This procedure might also be useful for SN identification of other deep draining malignancies.