Evaluation of diagnostic value of FDG-PET/CT study in detection of metastases in malignant melanoma patients

Aim: Positron emission tomography is showing utility in the detection of metastatic tumors from multiple primary sites. Malignant melanoma is a kind of neoplasm which highly metabolized fluorodeoxyglucose (FDG). The purpose of the study was to determine sensitivity and specificity of FDG-PET/CT scanning for the detection of metastases in patients with malignant melanoma.
Material and methods: We performed a retrospective study of FDG-PET/CT images in 39 melanoma patients. FDG-PET/CT examinations were conducted in the Department of Nuclear Medicine in Bydgoszcz between 2003 and 2005. FDG-PET/CT studies were performed to evaluate the actual clinical staging particularly in patients with suspected metastases in conventional radiological studies. Lymph node metastases were diagnosed in 8 patients. PET/CT images were performed on the integrated Biograph SL scanner (Siemens).
Results: Positron emission tomography confirmed distant metastases identified in conventional imaging in 14 (36%) patients. In 19 (49%) patients FDG-PET/CT and conventional images both excluded distant metastases. Divergent results of standard radiological examinations and PET/CT scanning were obtained in 6 (15%) patients. FDG-PET/CT scanning had a sensitivity of 85% and specificity of 90%.
Conclusions: FDG-PET/CT scanning is an extremely sensitive and specific diagnostic method allowing the proper staging in patients with suspicion of distant melanoma metastases.