Clinical application of¹⁸F-FDG PET/CT in malignant melanoma patients

Background: Positron Emission Tomography (PET) is a sensitive and specific functional imaging tool that allows metabolic mapping of the disease process in humans. One of the disadvantages of ¹⁸F-FDG PET is poor anatomical discrimination in spite of several merits. In contrast, CT achieves excellent anatomical resolution, tissue differentiation and high imaging speed but offers little functional information. Combining PET and CT has the potential to improve local discrimination, increase specificity and reduce interpretative errors. Objective: The aim of Oris study was to evaluate the usefulness of PET/CT as a diagnosis or therapeutic response assessment tool in malignant melanoma patients. Methods: We performed whole body ¹⁸F-FDG PET/CT for evaluation of malignant melanoma in 20 patients. PET/CT scans were carried out before operations and/or after the chemotherapy period. Results: The patients had stages of T1N0MO in 5 cases, T2N0M0 in 7 cases, T3N0M0 in 2 cases, T4N0M0 in 3 cases, and T3N0M1, T4N3M1, and T4N2M0 in each of these cases. It was thought that PET/CT was significant in detecting regional lymph node metastasis and distant metastasis of malignant melanoma. In addition, FDG uptake in primary skin tumors tended to increase in proportion to depth of the primary skin tumors. Conclusion: Further prospective clinical trials will help clarify the optimal protocols for different clinical indications and therefore ¹⁸F-FDG PET/CT is a useful diagnostic and prognostic tool in the management of malignant melanoma.