Comparison of F-18-FDG PET/CT and ultrasound in staging of patients with malignant melanoma

Objective: To evaluate the sensitivity and specificity of 2-18fluoro-2-deoxy-D-glucose positron emission tomography/computed tomography (F-18-FDG PET/CT) and ultrasound (US) for staging patients with malignant melanoma. Methods: In total, 258 patients (112 men and 146 women; mean age, 61 +/- 16years) met the primary inclusion criteria for malignant melanoma without further malignancy proven by histopathology. This was a retrospective study of the diagnostic accuracy. All data were obtained from the hospital's patient and radiology information system. Patients formed a consecutive series and were examined by 18F-FDG PET/CT and 176 additionally by US (US as a whole [wUS], peripheral lymph nodes [pUS], abdomen [aUS]), with a total of 584 F-18-FDG PET/CT and 697 US. F-18-FDG PET/CT and US revealed 824 and 726 lesions, respectively. Per-patient, per-examination, and per-lesion analyses were also performed. The reference standards used were histopathology or resection of lesions, and follow-up controls using other imaging methods. Results: Significant differences (P < .05) were found in the per-examination for the sensitivity of F-18-FDG PET/CT (0.80) compared to wUS (0.63) and pUS (0.61), and the specificity of F-18-FDG PET/CT (0.96) compared to wUS (0.98) and aUS (0.99). In the PLA, there were significant differences in sensitivity and specificity for F-18-FDG PET/CT (0.83, 0.91) compared to wUS (0.61, 0.98), pUS (0.60, 0.98), and aUS (0.61, 0.99). Conclusion: F-18-FDG PET/CT is preferable to US for detecting both lymph node and abdominal metastases.