Extreme heat effective in treating some kidney cancers

Image-guided radiofrequency ablation — using heat to destroy cancers — can preserve kidney function and avoid kidney dialysis for patients with solid renal tumors who are not surgical candidates, a new study indicates.

“We have been able to successfully destroy 50 out of 51 renal tumors in 32 patients,” says Michael Farrell, MD, consultant radiologist at Mayo Clinic in Rochester, MN, and the lead author of the study.

The easiest tumors to treat with radiofrequency ablation are those that are “growing on the outer surface of the kidney because surrounding fat insulates the tumor and insures the necessary temperatures can be acquired in order to achieve tumor cell destruction,” says Dr. Farrell. Centrally located tumors are more difficult to successfully treat, he says.

“We have followed the patients for between 1 and 27 months, and none of them have had cancer recurrence on imaging,” says Dr. Farrell. “We can potentially re-treat patients with radiofrequency ablation if their cancer returns,” he adds.

“The success rate is encouraging, but our follow-up time is relatively short. “This is not an alternative to definite surgical resection, but is an option for patients with decreased renal function, including those who’ve had a prior nephrectomy,” Dr. Farrell says. “Our aim would be to preserve renal function and avoid dialysis.” It is also an option for patients with coexisting medical morbidities which make them unsuitable for surgery, he says.

There is a low incidence of side effects in treatment, adds Dr. Farrell. Minor complications (in four patients) included pain, development of small fluid collection, and bleeding, all of which resolved themselves, he says. Major complications (in two patients) included damage to a small artery, which in turn destroyed a small area in the kidney, and heat damage to a nerve which has led to chronic, but gradually resolving, pain in the patient.

“We are seeing an increase in the number of renal tumors, especially in elderly patients. New imaging methods are detecting them incidentally, that is, patients are coming in for a radiologic examination for another reason, and the renal tumor is being found,” says Dr. Farrell. Ablation is a treatment option for these patients if they are not surgical candidates or have poor renal function, he says.

Dr. Farrell will present his study on May 8 during the American Roentgen Ray Society Annual Meeting in San Diego.

Contact: Keri J. Sperry (703) 858-4306
Danica Laub (703) 858-4332
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