Impact of F-FDG-PET/CT on surgical management in patients with advanced melanoma: an outcome based analysis.

PURPOSE

To evaluate the influence of F-FDG-PET/CT on clinical decision making and outcome in advanced melanoma patients planned for radical metastasectomy.

METHODS AND MATERIALS

A cohort of 333 patients with mainly stage III/IV melanoma having a PET/CT for clinical reasons was prospectively enrolled in our oncologic PET/CT registry between 2013 and 2015. Referring physicians completed questionnaires regarding their intended management for each patient before and after PET/CT. Management changes after PET/CT were classified as major and minor changes. A subgroup of 107 patients (stage I, N = 5; stage II, N = 3; stage III, N = 42; stage IV, N = 57) was planned for complete metastasectomy initially, based on conventional imaging. Management changes and outcome were evaluated by linkage with the information obtained from patients' medical records.

RESULTS

In 28 of 107 patients (26%), the surgical treatment plan remained unchanged after PET/CT. In 24 patients (22%), minor changes were performed, such as enlargement or reduction of the surgical field. In 55 patients (51%, 95% CI 42%-61%) major changes of the intended treatment plan occurred; of those, 20 patients (19%) were classified to be tumor-free with PET/CT, 32 patients (30%) were found to have multiple previously unrecognized metastases and had to be treated by systemic therapy, three patients (3%) had to be changed to palliative radiotherapy or isolated extremity perfusion. The 1-year and 2-year overall survival (OS) in patients with complete metastasectomy (N = 52) was 90% and 79%, respectively. Systemically treated patients (N = 32) resulted in 1-year OS of 72% and 2-year OS of 61%. Eleven of 32 patients (34%) with systemic therapy experienced a complete response. Until December 2016, all 20 patients classified as tumor-free by PET/CT were alive.

CONCLUSION

The study confirms the high impact of PET/CT on clinical management in patients with advanced melanoma planned for radical metastasectomy. PET/CT resulted in frequent management changes, preventing futile surgery in half of the patients.