Influence of 18F-FDG PET/CT on therapy management in patients with stage III/IV malignant melanoma

Purpose To evaluate the influence of F-18-FDG PET/CT in comparison to CT alone on treatment decisions in patients with advanced melanoma and to analyse the 5-year survival data in comparison to literature data. Methods Therapy management in 64 consecutive patients (primary staging n = 52; surveillance n = 12) with stage III/IV melanoma who underwent F-18-FDG PET/CT between 2004 and 2005 in our department was retrospectively analysed. Treatment decisions were made by two dermatooncologists for each patient twice, first based on the CT results and then based on the PET/CT results. Therapy changes based on the PET/CT results were classified as "major" (e.g. change from metastasectomy to systemic therapy) or "minor" (e.g. change from first to second line chemotherapy). The 5-year survival data of different patient cohorts were calculated. Results In the 52 patients in the primary staging group, the results of F-18-FDG PET/CT led to therapy change in 59 % and a major therapy change in 52 %. F-18-FDG PET/CT led to the avoidance of futile operations in 13 patients with suspicious lesions on CT that were deemed nontumorous on PET/CT. In the 12 patients in the surveillance group, the results of F-18-FDG PET/CT led to therapy change in 33 % and a major change in 17 %. The 5-year survival rates were 30 % in the entire cohort, 34 % in the primary staging group, and 17 % in the surveillance group. A significant overall survival benefit was observed in patients in whom F-18-FDG PET/CT excluded metastases or in whom metastases could be completely removed compared with patients who were not eligible for surgery (41 % vs. 10 %). Conclusion Primary staging of patients with stage III/IV melanoma should be performed with F-18-FDG PET/CT, leading to higher diagnostic accuracy and enabling individualized therapeutic management, especially optimal patient selection for metastasectomy. This strategy may extend long-term survival even in patients with advanced disease.