Nephron-sparing techniques offer multiple advantages for small tumors

Advances in nephron-sparing procedures have given them clear advantages over radical nephrectomy for most small renal masses, according to Stephen E. Strup, MD, of the University of Kentucky, Lexington.

Partial nephrectomy, radiofrequency (RF) ablation, and cryoablation are all showing good results, with even more treatments under development, Dr. Strup said at the Urology Congress here.

The diagnosis of small renal masses-those less than 4 cm-is increasing, in part because of improved imaging techniques. Most renal cell carcinomas grow slowly-just 0.28 cm per year-and only 1% are metastatic, so observation is an option. But patients often won't accept their cancer passively.

Dr. Strup acknowledged that the gold standard remains radical nephrectomy. But, Dr. Strup said, "We now know partial nephrectomy is just as good an operation for the small mass as nephrectomy."

And partial nephrectomy offers clear advantages when a patient has only one kidney, bilateral renal lesions, contralateral renal disease, or a systemic disease such as diabetes, he said.

In RF ablation, a high-frequency alternating current in the radiowave spectrum is transmitted to tissues through an array needle, generating heat. RF ablation is most suited for use in renal masses of less than 3 cm and in high-risk patients such as the elderly or those with a co-morbidity or renal insufficiency, bilateral and/or multiple turmors, or a solitary kidney. The tumor should be exophytic and not next to the bowel, ureter, or central collecting system.

In cryoablation, small probes circulate liquid nitrogen or argon gas to freeze the mass and 0.5 cm beyond it. Cryoablation is suited to approximately the same patients as RF ablation, with small masses less than 3 cm.

Given this array of options, urologists are faced with this decision: "Cut it out, freeze it, or boil it away?" The answer depends on the patient and the mass, but overall, Dr. Strup's favorite is cryoablation.

"Cryo is my first choice," he said. "I like freezing because I can see what I freeze."