Percutaneous computed tomography-guided cryoablation for renal tumor: Experience in 30 cases

Background: Percutaneous cryoablation is a minimally invasive alternative for surgical resection of a renal tumor. We report our experience with applying computed tomography-guided cryoablation in renal tumors, focusing on the technique, safety, and treatment response.

Methods: We retrospectively reviewed the medical records of patients who received cryoablation from October 2009 to August 2013 for renal tumor diagnosed by imaging studies performed at Taipei Veterans General Hospital, Taipei, Taiwan. Patient comorbidities and tumor morphology, technical success rate, tumor control rate, renal function change, and complications were recorded.

Results: A total of 30 patients (32 tumors) were treated, comprising 30 renal cell carcinomas and two angiomyolipomas. The mean age of the patients was 73.7 years (range, 34-89 years). The patients were referred for percutaneous cryoablation arising from old age, medical comorbidities, or preexisting malignancy. The mean follow-up period was 15.2 months (range, from 32 days to 47.4 months). According to the Clavien-Dindo classification, surgical complications included one Grade III, four Grade II, and two Grade I complications. The mean decrease in hemoglobin was 0.77 g/dL (range, from +1.1 g/dL to -3 g/dL). The mean hospital stay after cryoablation was 2.2 days (range, 1-10 days). Incomplete ablation was noted in two patients and local tumor recurrence in two patients. One of them received repeated cryoablation and achieved successful local control. Of the 22 renal cell carcinoma patients with follow-up period > 6 months, 19 patients achieved successful local tumor control (86.4%). The percentage change of glomerular filtration rate before and 3-6 months after the procedure was +1.9%, which was statistically nonsignificant (p = 0.94).

Conclusion: Computed tomography-guided percutaneous cryoablation is a safe and effective technique for treating renal tumors with excellent renal function preservation.