The kidneys are each filled with tiny tubules that clean and filter the blood; this process removes waste and makes urine. Renal cell cancer (RCC) is a malignancy involving these tubules of the kidney. Surgery is the mainstay of treatment for kidney cancer, as the cancer is typically resistant to radiation and chemotherapy. Historically, surgical treatment of RCC consisted of a radical nephrectomy, which involves removal of the entire kidney, local lymph nodes, and any cancer in the area surrounding the kidney. The trend in the surgical management of RCC, however, is to perform less aggressive surgery when possible.
Cryoablation is a minimally invasive technique that uses extremely cold temperatures to “freeze” small cancers. In patients with cancer that is less than or equal to 5.0 cm in diameter, cryoablation appears to be a promising approach for removing the cancer. Two recent studies evaluated two different methods of cryoablation.
Researchers from the Cleveland Clinic evaluated CT-Nav®, a stereotactic surgical navigation system that delivers cryoablation and radiation to a tumor via a cryoprobe. This reduces the radiation exposure compared with conventional radiation treatment. This was a prospective pilot study designed to evaluate the feasibility, safety, and accuracy of the system. The system was used to cryoablate 13 tumors in 10 patients. The mean tumor size was 2.2 cm; mean operation time was 155 minutes; and mean length of hospital stay was 9.5 hours. There were no complications. The researchers concluded that this method offers potential for patients with kidney cancer.
Researchers from the University of Southern California evaluated laparoscopic renal cryoablation in 80 patients with renal tumors; the mean tumor size was 2.3 cm. All patients were treated by a single surgeon and then followed for a minimum of five years. At five years overall survival was 84%, and progression-free survival was 81%. At ten years overall survival was 51%, and progression-free survival was 78%. The researchers concluded that this as an effective treatment for select patients.
The results of these two studies indicate that cryoablation may start to play a larger role in the surgical treatment of kidney cancer.