Percutaneous thermal ablation: A new treatment line in the multidisciplinary management of metastatic leiomyosarcoma?

BACKGROUND: The role of percutaneous thermal ablation (PTA) in the multidisciplinary management of metastatic leiomyosarcoma (LMS) has not been thoroughly evaluated. MATERIALS AND METHODS: Single institution retrospective review of all patients with LMS metastases treated with PTA from June 2004 to December 2014. Iterative PTAs were performed as a multifocal treatment for all recurrent or residual macroscopic metastases discovered on imaging after completion of systemic treatment, or alternatively as a targeted treatment of selective metastases found to be progressive on systemic treatment. The primary endpoint was the time to untreatable progression (TTUP), recorded as the time elapsed between the first PTA and the re-initiation of systemic chemotherapy to treat disease progression. Secondary endpoints were overall survival, the 1, 3 and 5-year survival rates, and local control rate. RESULTS: A total of 93 LMS metastases (average diameter 18.2 mm, range 3-45 mm) were successfully treated in 30 patients over 50 treatment sessions with a median follow-up of 34.6 months. The median TTUP was 14.2 months (range 2.4-122.8). The median overall survival after PTA was 48.3 months and the 1, 3 and 5-year overall survival rates were 96.7% (95%CI 84.3-100.0%), 62.0% (95%CI 45.8-84.0%), and 28.3% (95%CI 13.5-59.1%) respectively. Local control rate at 1 year was 95.2% and at 3 years was 89.4%. CONCLUSION: Iterative PTA is an effective treatment line option for appropriately selected patients with metastatic LMS that can delay re-initiation of systemic chemotherapy.