Whole-Body Imaging for the Primary Staging of Melanomas-A Single-Center Retrospective Study

Background: Melanoma staging at diagnosis predominantly depends on the tumor thickness. Sentinel lymph node biopsy (SLNB) is a common tool for primary staging. However, for tumors of >4 mm with ulceration, 3D whole-body imaging and, in particular, Fluor-18-Deoxyglucose positron emission tomography combined with computed tomography (F-18-FDG-PET/CT), is recommended beforehand. This study aimed to investigate the real-world data of whole-body imaging for initial melanoma staging and its impact on the subsequent diagnostic and therapeutic procedures. Methods: In this retrospective single-center study, 94 patients receiving F-18-FDG-PET/CT and six patients with whole-body computed tomography (CT) scans were included. The clinical characteristics, imaging results, and histologic parameters of the primary tumors and metastases were analyzed. Results: Besides the patients with primary tumors characterized as pT4b (63%), the patients with pT4a tumors and pT3 tumors close to 4 mm in tumor thickness also received initial whole-body imaging. In 42.6% of the patients undergoing F-18-FDG-PET/CT, the imaging results led to a change in the diagnostic or therapeutic procedure following on from this. In 29% of cases, sentinel lymph node biopsy was no longer necessary. The sensitivity and specificity of F-18-FDG-PET/CT were 66.0% and 93.0%, respectively. Conclusion: Whole-body imaging as a primary diagnostic tool is highly valuable and influences the subsequent diagnostic and therapeutic procedures in a considerable number of patients with a relatively high tumor thickness. It can help avoid the costs and invasiveness of redundant SLNB and simultaneously hasten the staging of patients at the time of diagnosis.