Stereotactic Percutaneous Cryoablation for Renal Tumors: Initial Clinical Experience

Purpose

Percutaneous imaging guided tumor ablation has an increasingly prominent role as minimally invasive treatment for renal tumors. Precise cryoprobe placement is essential for successful ablation. CT-Nav® is a novel stereotactic surgical navigation system with the potential to achieve precise percutaneous cryoprobe placement while decreasing radiation exposure compared to conventional computerized tomography guided procedures.

Materials and Methods

We performed a prospective pilot study to evaluate the technical feasibility, safety and accuracy of the system during renal cryoablation. Patients with enhancing renal masses amenable to renal cryoablation underwent preoperative computerized tomography with a preplaced tracking sensor taped to the body. Using a stereroscopic infrared camera the tracking sensor was located 3-dimensionally and a tracking handle was used to guide the cryoprobe percutaneously based on preoperative preloaded computerized tomography. Demographic and perioperative data were added prospectively to an institutional review board approved database. Immediately after cryoprobe placement computerized tomography was repeated to confirm placement accuracy.

Results

A total of 13 tumors in 10 patients were successfully cryoablated with the novel navigational system. Mean tumor size was 2.2 cm. Preoperative biopsy revealed renal cell carcinoma in 9 cases. Mean operative time was 155 minutes. No intraoperative or postoperative complications were noted. Mean length of stay was 9.5 hours. Mean targeting registration error was 4.2 mm.

Conclusions

Stereotactic percutaneous cryoablation for renal tumors offers the potential for safe, precise needle placement.

Key Words: kidney, kidney neoplasms, tomography, x-ray computed, stereotaxic techniques, cryosurgery

Abbreviations and Acronyms: 3D, 3-dimensional, CT, computerized tomography, RET, radiation exposure time