Recurrence and Survival Outcomes after Percutaneous Thermal Ablation of Oligometastatic Melanoma

Objectives To evaluate focal treatment of melanoma metastases and to explore whether any potential extended survival benefit exists in a select patient population. Patients and Methods All patients who underwent image-guided local thermal ablation of metastatic melanoma over an 11-year period (January 1, 2002, to December 31, 2013) were retrospectively identified using an internally maintained clinical registry. Only patients with oligometastatic stage IV disease amenable to complete ablation of all clinical disease at the time of ablation were included in the analysis. Overall survival and median progression-free survival periods were calculated. Results Thirty-three patients with primary ocular or nonocular melanoma had 66 metastases treated in the lungs, liver, bones, or soft tissues. Eleven (33%) patients were on systemic medical therapy at the time of the procedure. The median survival time was 3.8 years (range, 0.5-10.5 years), with a 4-year estimated survival of 44.1% (95% CI, 28%-68%). Local recurrence at the ablation site developed in 15.1% (5 of 33) of the patients and 13.6% of the tumors (9 of 66). The median progression-free survival time was 4.4 months (95% CI, 1.4 months to 10.5 years), with an estimated 1-year progression-free survival of 30.3% (95% CI, 18%-51%). A subgroup analysis identified 11 patients with primary ocular melanoma and 22 with nonocular melanoma, with a median survival time of 3.9 years (range, 0.9-4.7 years) and 3.8 years (range, 0.5-10.5 years), respectively (P=.58). There were no major complications and no deaths within 30 days of the procedure. Conclusion Selective use of image-guided thermal ablation of oligometastatic melanoma may provide results similar to surgical resection in terms of technical effectiveness and oncologic outcomes with minimal risk.