Safety and Efficacy of Radiofrequency Ablation for Hepatic Metastases from Gastrointestinal Stromal Tumor.

ABSTRACT

PURPOSE: To evaluate the safety and efficacy of radiofrequency (RF) ablation for hepatic metastases from gastrointestinal stromal tumor (GIST). MATERIALS AND METHODS: Retrospective review of a prospectively maintained database was performed between February 2002 and November 2010 and identified 29 patients with GISTs (18 male; age range, 35­77 y; median age, 61 y) who had undergone ultrasound-guided RF ablation for metastases detected in the liver. All patients had been treated with imatinib mesylate. Indications for RF ablation were tumor progression during medical therapy or the development of drug resistance after initial tumor control. The average number of target lesions per procedure was 2.3 (range, 1­8), and mean lesion diameter was 1.3 cm (range, 0.4­3.6 cm). RESULTS: For 69 lesions among 86 hepatic metastases, RF ablation was successfully performed according to the protocol currently in use. In 17 hepatic metastases in 13 patients, RF ablation was not performed because of poor lesion visibility or possible thermal damage to adjacent organs. Major complications included bleeding at the ablation site in one patient and peritoneal seeding near the ablation tract in another patient. Technical effectiveness was achieved for 66 of 69 lesions (95.6%). The median follow-up period was 33.1 months (range, 12.3­108.6 mo). Four of 66 lesions (6%) showed local recurrence at 3.2­10.5 months. Four patients died of disease progression. The median overall survival period was 90.2 months (range, 12.3­108.6 mo). CONCLUSIONS: RF ablation appears to be a safe and effective treatment for hepatic metastases of GIST when medical therapy fails.