Utility of Preoperative 18F-FDG PET/CT and Brain MRI in Melanoma Patients with Palpable Lymph Node Metastases

Abstract

The aims of this prospective study were to determine the diagnostic value of (18)F-fluorodeoxyglucose positron emission tomography/computed tomography (FDG PET/CT) and brain MRI in melanoma patients with palpable lymph node metastases and to assess the impact of these imaging modalities on their management. Between October 2006 and March 2009, PET/CT and brain MRI were performed in 70 melanoma patients with palpable nodal lymph node metastases and without evidence of systemic dissemination after physical examination. Hypermetabolic PET/CT lesions were examined by histology or cytology or were imaged further and followed if no pathology confirmation could be obtained. PET/CT findings changed the intended regional node dissection in 26 patients (37%). PET/CT was false negative in 4 patients (6%) and false positive in 1 (1%). This resulted in a sensitivity of 87%, specificity of 98%, accuracy of 93%, positive predictive value of 96%, and negative predictive value of 91%. MRI revealed brain metastases in 5 patients (7%). The overall survival of patients without additional lesions on PET/CT was 84% after 2years, which was better than the 56% in patients with additional metastases (P<.001). PET/CT has an 87% sensitivity and 98% specificity in the detection of other metastases in melanoma patients with palpable lymph node involvement. PET/CT leads to a change in the planned regional node dissection in 37% of the patients in this study. MRI revealed brain metastases in 5 patients (7%). PET/CT findings correlate with survival.