Percutaneous renal cryoablation has proven to be a safe and effective alternative technique for patients who cannot undergo surgery and need to preserve their renal function, according to a study published in the December 2013 issue of the American Journal of Roentgenology.

Small renal tumors associated with kidney carcinomas, the third most common type of urologic cancer, are often identified by CT and MRI techniques. “These small renal tumors, smaller than 40 mm in diameter (T1a tumors), have a better prognosis than larger tumors because they are discovered at an earlier stage and subsequent development of metastasis is rare,” wrote Xavier Buy, MD, of the Hospital University of Strasbourg, France, and colleagues.

However, thermal treatments like radiofrequency and cryoablation are also acceptable alternative techniques to treat the small solid tumors in patients. Thus, Buy and colleagues designed a study to assess the efficacy and safety of percutaneous renal cryoablation.

The authors performed a prospective nonrandomized evaluation of 120 renal tumors in 95 patients treated with percutaneous cryoablation because their condition didn’t allow for surgery. The evaluation focused on tumor characteristics, complications, hospital course, treatment success based on MRI follow-up, and effect on renal function.

Results revealed that the mean tumor size was 26 mm, with 20 tumors larger than 40 mm. Of the tumors treated, 91 were addressed with CT and 29 with MRI guidance. Based on the Clavien-Dindo classification, five grade II complications and four grade III-V complications occurred. The technical success rate was 94 percent, with two tumors requiring a second session of cryoablation due to recurrence or residual tumor. The overall survival was 96.7 percent after 12 months of treatment, and the disease-free survival rate was 96.4 percent.

“Improvements in percutaneous thermal protection techniques allow treatment of tumors in an anterior location,” wrote Buy and colleagues. “Percutaneous cryoablation is effective for preserving renal function, even in patients with a single kidney. Moreover, in cases of incomplete treatment, cryoablation can be repeated and does not preclude salvage surgery. However, without larger series with longer follow-up, this technique should still be reserved for patients whose condition does not allow surgery,” they concluded.