By literally freezing prostate cancer cells to death, radiologists can effectively treat prostate cancer in some patients while reducing complication rates, preliminary results of a study show. The new procedure, trans- rectal ultrasound-guided cryoablation, also costs less than traditional prostate cancer treatments, the study indicates.
Of the 310 men treated with the technique so far, 90% have had negative biopsies, said Dr. Duke Bahn, chair of the Department of Radiology at Crittenton Hospital in Rochester, Michigan. Follow-up of these patients ranged from 3 months to 2 years, Dr. Bahn told the American Roentgen Ray Society at its annual meeting in Washington, D.C.
Patients with cancer confined to the prostate gland or those whose cancer has spread near the gland are candidates for the freezing procedure, said Dr. Bahn. Probes are inserted through small skin punctures into the prostate gland. Liquid nitrogen is circulated through the probes and the entire prostate is frozen. When the prostate thaws, the cells rupture and die, he said. "The freezing process is carefully monitored by high resolution ultrasound to avoid injuries to adjacent organs," said Dr. Bahn. Patients usually are only in the hospital overnight, and they can return to their normal routine in about 2 weeks.
The cost of cryoablation is about one-third to one-half that of surgery or radiation therapy, Dr. Bahn noted. Complication rates appear to be much lower than rates associated with surgery. For example, incontinence occurs in at least 30% of patients who undergo surgery. "Our incontinence rate is only 1%," said Dr. Bahn.
The cryoablation procedure can be repeated if it fails, said Dr. Bahn. Patients also can choose to undergo radiation therapy or surgery if cryoablation proves ineffective, he added.
"We are very optimistic about this procedure," said Dr. Bahn. However, he cautioned, long-term clinical trials need to be done to determine whether this treatment increases overall survival. Transrectal ultrasound-guided cryoablation is available in about 100 institutions across the United States.