Radiofrequency Ablation of T1a Renal Cell Carcinomas within Renal Transplant Allografts: Oncologic Outcomes and Graft Viability.

ABSTRACT

PURPOSE: To evaluate oncologic outcomes and graft viability after percutaneous radiofrequency (RF) ablation of renal cell carcinoma (RCC) developing within renal transplant allografts. MATERIALS AND METHODS: A single-institution, retrospective study reviewed all patients treated with RF ablation for RCC between February 2004 and May 2016. Ten patients were identified (age 49.6 y ± 12.6; 9 men, 1 woman) with 12 biopsy-confirmed RCC tumors within the allograft (all T1a, mean diameter 2.0 cm ± 0.7). Mean time from transplant to RCC diagnosis was 13.2 years ± 6.3. RF ablation was performed on an outpatient basis using conscious sedation. Procedural efficacy, complications, oncologic outcomes, and allograft function were evaluated. Statistical analysis with t tests and Pearson correlation compared allograft function before and after RF ablation and impact of proportional ablation size to allograft volume on function after ablation. RESULTS: Technical success rate and primary technique efficacy were 100% (12/12). No local or distant RCC progression was seen at mean follow-up of 54.3 months ± 38.7 (range, 9-136 months). Graft failure requiring hemodialysis or repeat transplantation occurred in 3 patients (26, 354, and 750 d after RF ablation), all of whom had glomerular filtration rate (GFR) < 30 mL/min/1.73 m2 before ablation. For all patients, mean GFR 6 months after RF ablation (35.8 mL/min/1.73 m2 ± 17.7) was not significantly different (P = .8) from preprocedure GFR (36.2 mL/min/1.73 m2 ± 14.3). Proportional volume of allograft that was ablated did not correlate with immediate or long-term GFR changes. One patient died of unrelated comorbidities 52 months after ablation. No major complications occurred. CONCLUSIONS: RF ablation of renal allograft RCC provided effective oncologic control without adverse impact on graft viability.