CIO 2021-35 Long-term Outcomes in Image-Guided Radiofrequency, Microwave, and Cryoablation of Small Renal Masses

Purpose: The purpose of this study is to examine a 5-year institutional experience of clinical outcomes for percutaneous image-guided ablation for small renal neoplasms utilizing radiofrequency ablation, cryoablation, or microwave ablation at a tertiary academic medical center.

Material and Methods: Between January 2015 and January 2020, 48 consecutive patients underwent image-guided thermal ablation techniques (microwave (MW), radiofrequency (RF), and cryoablation) at a tertiary academic medical center. Patient demographics, patient functional status, and tumor characteristics were categorized. Outcome variables included technical success rates, radiographic response rates, overall survival (OS) from all-cause mortality and progression free survival (PFS). Furthermore, pre- and post-ablation glomerular filtration rates (GFR), creatinine, and hemoglobin were examined.

Results: There were 30 (62.5%) males and 18 (37.5%) females, and the average age was 65.5 ± 13 years. Forty-one patients were Caucasian and 7 were African American. There was a total of 48 treatment executed thermal ablations: MW ablation (n = 30; 62.5%), Cryoablation (n = 15; 31.3%), RF ablation (n = 3; 6.3%). Computed Tomography (CT) and Ultrasound (US) imaging guidance was used in 100% of cases. The technical success rate was 100%. Complete response on follow-up CT imaging was 97.9% for 1- and 3-months (n = 48), and 100% at 6-months (n = 30). The OS at 30-days, 1-year, 3-years, and 5-years were 100%, 93.8%, 89.6%, and 87.5%, respectively. The PFS was 35.1 ± 21.0 months. The mean creatinine value was 1.3 mg/dl pre-ablation and 1.5 mg/dl post-ablation therapy (p > 0.05); the mean GFR was 82.3 ml/min pre-ablation and 79.2 ml/min post-ablation (p > 0.05); and the mean hemoglobin was 13.3 g/dl pre-ablation and 12.6 g/dl post-ablation (p > 0.05).

Conclusions: Percutaneous ablation therapies are safe and effective curative-intent modalities for treatment of small renal masses, with promising long-term outcomes.