Portable Gamma Camera Guidance in Sentinel Lymph Node Biopsy: Prospective Observational Study of Consecutive Cases

Abstract

Background: Sentinel lymph node biopsy is the most important tool available for node staging in patients with melanoma. Objectives: To analyze sentinel lymph node detection and dissection with radio guidance from a portable gamma camera. To assess the number of complications attributable to this biopsy technique. Methods: Prospective observational study of a consecutive series of patients undergoing radioguided sentinel lymph node biopsy. We analyzed agreement between nodes detected by presurgical lymphography, those detected by the gamma camera, and those finally dissected. Results: A total of 29 patients (17 women [62.5%] and 12 men [37.5%]) were enrolled. The mean age was 52.6 years (range, 26-82 years). The sentinel node was dissected from all patients; secondary nodes were dissected from some. In 16 cases (55.2%), there was agreement between the number of nodes detected by lymphography, those detected by the gamma camera, and those finally dissected. The only complications observed were seromas (3.64%). No cases of wound dehiscence, infection, hematoma, or hemorrhage were observed. Conclusions: Portable gamma-camera radio guidance may be of use in improving the detection and dissection of sentinel lymph nodes and may also reduce complications. These goals are essential in a procedure whose purpose is melanoma staging.

Evaluation of sentinel lymph node localization in malignant melanoma by preoperative semiconductor gamma camera and planar lymphoscintigraphy

“…SPECT/CT also detect nodes close to the injection site, accurately localize axillary and extra‐axillary nodes, exclude non‐nodal false positive sites of uptake and contamination sites which are very essential in overweight patients for whom the identification of draining nodes by planar scintigraphy has failed 5–8 . Conventional gamma cameras are not readily available in some SLN centers or the need to free up time on gamma camera time in a nuclear medicine department, coupled with the desire to have a direct imaging device in the operating theatre; thus, providing more information for the surgeon at the time of operation, has led to the development of high‐resolution portable handheld gamma cameras utilizing either scintillation crystals or semiconductors detectors 9,10 …”

“…[5][6][7][8] Conventional gamma cameras are not readily available in some SLN centers or the need to free up time on gamma camera time in a nuclear medicine department, coupled with the desire to have a direct imaging device in the operating theatre; thus, providing more information for the surgeon at the time of operation, has led to the development of high-resolution portable handheld gamma cameras utilizing either scintillation crystals or semiconductors detectors. 9,10 This study evaluates the effectiveness of a small fieldof -view, handheld preoperative semiconductor-based gamma camera device CrystalCam (Crystal Photonics GmbH, Berlin, Germany) in localizing SLN in malignant melanoma patients compared to both conventional planar lymphoscintigraphy and hybrid SPECT/CT; where hybrid SPECT/CT was considered the gold standard. Although the physical performance evaluation of Crys-talCam in accordance with NEMA standard have been reported by Knoll et al,11 this work includes phantom studies aimed at evaluating the camera's sensitivity and resolution for a range of very low activity uptakes (0.034 to 4.432 MBq) at limited counting interval of 3 s only.…”