Intraoperative Fluorescence Imaging for Sentinel Lymph Node Detection: Prospective Clinical Trial to Compare the Usefulness of Indocyanine Green vs Technetium Tc 99m for Identification of Sentinel Lymph Nodes.

IMPORTANCE: The metastatic status of regional lymph nodes is the most relevant prognostic factor in breast cancer, melanoma, and other solid organ tumors with a lymphatic spread. The current gold standard for detection and targeted excision of the sentinel lymph node is preoperative lymphoscintigraphy with technetium Tc 99m. Because of the worldwide shortage of technetium Tc 99m, physicians are looking for nonradioactive dyes for sentinel lymph node labeling. Based on several retrospective studies, the fluorescent dye indocyanine green is considered a possible alternative to technetium Tc 99m.

OBJECTIVE: To analyze the feasibility and clinical benefit of intraoperative near infrared fluorescence sentinel lymph node excision (SLNE) compared with standard technetium Tc 99m-guided SLNE using malignant melanoma in which SLNE is firmly established.

DESIGN, SETTING, AND PARTICIPANTS: Analysis of a prospective clinical trial at the Skin Cancer Center, University Hospital Essen. Eighty patients with malignant melanoma on the trunk or extremities (upper and lower) who were scheduled to undergo SLNE were included in this study from January 1, 2013, to June 27, 2014.

MAIN OUTCOMES AND MEASURES: Concordance of preoperative and intraoperative sentinel lymph node detection rates.

RESULTS: During the study period, 80 patients were operated on with an additional intraoperative application of a near infrared fluorescent dye. In these 80 surgical procedures, 147 SLNs were excised. Detection of a technetium Tc 99m-marked SLN before surgery was possible in all cases. Intraoperative visualization of the SLN by indocyanine green before skin incision was successful in only 17 of 80 patients (21%). The number of SLNs identified using the near infrared fluorescence technique in the operative site after skin incision and initial tissue preparation was 141 of 147 (96%).

CONCLUSIONS AND RELEVANCE: Among patients in whom the lymph node basin cannot be predicted correctly (eg, in cutaneous melanoma on the trunk), the use of indocyanine green for SLN detection is severely limited compared with SLNE using standard technique guided by technetium Tc 99m. Therefore, SLNE with the use of radiocolloid, followed if possible by single-photon emission computed tomography, remains the gold standard.

TRIAL REGISTRATION: German Clinical Trials Register identifier DRKS00004619.