Percutaneous renal cryoablation: prospective experience treating 120 consecutive tumors.

OBJECTIVE: The purpose of this study was to evaluate the safety and efficacy of percutaneous renal cryoablation. SUBJECTS AND METHODS: A prospective nonrandomized evaluation of 120 renal tumors in 95 patients treated with percutaneous cryoablation because their condition did not allow surgery focused on tumor characteristics, complications, hospital course, treatment success based on MRI follow-up, and effect on renal function.
RESULTS: The mean follow-up period was 28 months (range, 6-63 months). The mean tumor size was 26 mm (range, 10-68 mm), including 20 tumors larger than 40 mm. Ninety-one tumors were treated with CT and 29 with MRI guidance. Fifty-six tumors were anterior, and thermal protection of adjacent organs with carbodissection or hydrodissection was used in 55 cases. According to the Clavien-Dindo classification, five grade II complications and four grade III-V complications occurred. The technical success rate was 94%. Two tumors required a second session of cryoablation because of recurrence or residual tumor. Twelve months after treatment the overall survival was 96.7%, and the disease-free survival rate was 96.4%, including patients with recurrent genetic tumors. Renal function remained unchanged even in the subgroup of patients with a single kidney.
CONCLUSION: Midterm follow-up shows that percutaneous renal cryoablation is an effective and safe alternative technique for patients whose condition does not allow surgery and that renal function is preserved. Cryoablation combined with percutaneous thermal protection techniques allows treatment of more complex tumors (large central tumors and tumors close to vulnerable structures). However, T1b and central tumors are associated with higher risk of incomplete treatment.