e19062 Background: Sentinel lymph node biopsy (SLNB) is the standard method for staging cutaneous melanoma and involves identifying the first node(s) draining a tumor, by detecting an intradermally-injected radioactive colloid tracer. Intra-operatively the sentinel node(s) are identified with a hand-held gamma probe. Pre-operative lymphoscintigraphy is obtained to identify draining lymph node basins, but requires coordinating schedules between nuclear medicine and the operating room. A pilot study utilizing Mobile Gamma Camera (MGC) devices in conjunction with conventional lymphoscintigraphy for intraoperative sentinel node localization provided clinical benefit in 20% of patients. However, utilizing MGC devices to localize lymph node basins at the time of surgery independent of conventional lymphoscintigraphy with a fixed gamma camera (FGC) has not been adequately studied. Here, we present the results of a clinical trial utilizing MGC devices to localize lymph node basins in a manner blinded to the FGC images in order to compare the modalities directly. Methods: In 2011-12 18 patients underwent Tc99 sulfur colloid lymphoscintigraphy, and MGC survey immediately pre-operative by the study surgeon. The study surgeon established an operative plan using the MGC survey, while blinded to lymphoscintigraphy results. SLNB was then performed with use of a gamma probe and intra-operative MGC imaging. Results: 22 lymph node basins were detected in 18 imaged patients by lymphoscintigraphy. All of these basins were identified by the study surgeon using the MGC device in the pre-operative setting prior to un-blinding. In every case the operative plan established based on pre-operative MGC imaging was confirmed by the FGC images. In two cases, additional information from the MGC images aided surgical decision-making. 5 of 22 lymph node basins were positive for metastasis. All of these basins were identified by pre-operative MGC imaging, and all individual positive nodes were identified by intra-operative MGC imaging. Conclusions: Pre-operative MGC imaging in sentinel lymph node biopsy can provide comparable information for operative planning, compared to standard FGC imaging.
Management of Malignant Melanoma of the Head and Neck Using Dynamic Lymphoscintigraphy and Gamma Probe–Guided Sentinel Lymph Node Biopsy
