Technique and Outcomes of Radiofrequency Ablation of Biopsy-Proven 3–4 cm T1a Renal Cell Carcinoma

<b>Objective:</b> The American Urological Association recommends ablation as an alternative treatment option for T1a RCC smaller than 3 cm. Our objective is to describe our technique and evaluate the outcomes of radiofrequency ablation (RFA) for biopsy-proven T1a RCC measuring 3-4 cm, compared to outcomes for tumors <3 cm. <b>Materials and Methods:</b> A single-center, retrospective review included patients with solitary, de novo, biopsy-proven T1a RCC who underwent RFA between January 2001 and December 2020. Using propensity score matching, patients with 3-4 cm lesions (Group A) were matched with patients with lesions less than 3 cm (Group B) based on the pathology, grade, duration of follow-up, another primary malignancy, age, and sex. Survival outcomes were estimated using the Kaplan and Meier product-limit estimator, and both groups were compared. <b>Results:</b> A total of 122 patients were included in the matched analyses. Eight patients were missing data on disease recurrence, leaving 114 patients with data on RFS and DFS (55 patients in Group A and 59 patients in Group B). The median tumor size in groups A and B was 3.3 cm and 2.2 cm, respectively. There was no statistically significant difference in the complication rate (<i>p</i> = 0.11) and local recurrence at the ablation site (<i>p</i> = 0.15). There was no statistically significant difference in overall survival (<i>p</i> = 0.93), recurrence-free survival (<i>p</i> = 0.45), or disease-free survival (<i>p</i> = 0.37). The metastasis-free survival and cancer-specific survival were 100% in both groups. <b>Conclusions:</b> RFA is a highly effective modality for the treatment of 3-4 cm T1a RCC, with long-term favorable oncologic and survival outcomes.