Local Control and Survival after Image-Guided Percutaneous Ablation of Adrenal Metastases

Purpose: To evaluate local control and survival after image-guided ablation of adrenal gland metastases. Materials and Methods: Image-guided ablations of adrenal metastases measuring < 5 cm performed at 2 academic medical centers between July 2002 and June 2016 were analyzed. There were 51 procedures performed on 46 tumors (mean diameter 2.8 cm +/- 1.1; range, 0.7-4.9 cm) in 38 patients (mean age 66 y; range, 41-80 y) with renal cell carcinoma (n = 17 patients; 45%), non-small cell lung cancer (n = 10 patients; 26%), and other primary malignancies (n = 11 patients; 29%). Treatment modalities included cryoablation (n = 30 procedures; 59%), radiofrequency ablation (n = 12 procedures; 24%) and microwave ablation (n = 9 procedures; 18%). Technical success, primary and secondary efficacy, local progression rate, local progression-free survival, and overall survival were assessed. Mean follow-up was 37 months (range, 2-128 months). Statistical analysis was performed with univariate Cox hazards regression and Kaplan-Meier analyses. Results: Technical success, primary efficacy, and secondary efficacy were 96%, 72%, and 76%. Local progression rate during all follow-up was 25%. Local tumor progression-free survival at 1, 3, and 5 years was 82%, 69%, and 55%. Overall survival at I, 3, and 5 years was 82%, 44%, and 34%. In 16 patients with isolated adrenal metastasis, median disease-free survival was 8 months; 4 patients had no evidence of disease during follow-up. Lung cancer was associated with decreased survival (hazard ratio 4.41, P =.002). Conclusions: Image-guided ablation can achieve local control for adrenal metastases < 5 cm.