Long-Term Survival after Percutaneous Image-Guided Microwave Ablation of Pathologically Proven Renal Cell Carcinoma

To determine the technical success (TS), long-term overall survival (OS), cancer-specific survival (CSS), and local tumor progression-free survival (LTPFS) of patients who underwent percutaneous microwave ablation (MWA) of renal cell carcinoma (RCC).

This IRB-approved, HIPAA-compliant study cohort included patients who underwent CT and contrast-enhanced ultrasound (CEUS) guided percutaneous MWA between 2013 and 2017 of biopsy-proven RCC. Patient demographics, tumor characteristics, and technical outcomes were compiled, and the OS, CSS, and LTPFS were derived with Kaplan-Meier analysis and log-rank test to evaluate differences. Complications were classified per the Clavien-Dindo system. Logistic regression was used for categorical outcomes, the chi-square test was used for categorical outcomes excluding repeated measures at the patient level, and the paired t-test was used for evaluating differences in pre- and post-ablation eGFR.

The study cohort comprised 86 biopsy-proven RCCs from 81 patients (mean age: 67.6 ± 16.9) with a median follow-up of 76.8 months. Overall, primary, and secondary TS were 100% (86/86), 98% (84/86), and 100% (10/10), respectively. The 10-year OS, CSS, and LTPFS rates were 76%, 85%, and 83%, respectively. The T1b subcohort 8-year LTPFS rate was lower compared to the T1a subcohort (p=0.003). The pre-ablation and 2 - 3 year post-ablation eGFR (58.5 vs 58.4 mL/min/1.73m²) were stable (p=0.932). There was a 2% overall incidence of complications, all grade I.

Percutaneous image-guided MWA of T1 RCC was associated with excellent long-term OS, CSS, and LTPFS, supporting MWA as an effective treatment option.