According to Onik, the 3-D transperineal biopsy complements the focal cryoablation approach because earlier detection of smaller tumors increases the likelihood that a small tumor can be treated using cryoablation. In his study, Onik restaged 180 patients who had previously undergone TRUS mapping biopsies who were considering conservative management for their cancer. The results showed that 70 percent of the men would have their management changed by the new information provided by mapping. Through mapping, more than 50 percent of men who were diagnosed with cancer on one side of the prostate gland with traditional TRUS biopsy had undetected cancer on the other side as well, he said. Management of prostate cancer is in great part determined by the Gleason score, a cancer ranking method indicating tumor grade and stage and the extent and location of a patient's disease. "When we restaged the men, we found that 22 percent of them experienced an increase in their Gleason score - meaning that they had a more aggressive cancer than was originally thought from their original biopsy. The 3-D mapping biopsy provided life-saving information," said Onik. "This biopsy technique allows us to map the location of the tumor with tremendous precision and has the potential to greatly affect the decisions we make about treating prostate cancer," Onik said. "The data are unequivocal. If you're doing 'watchful waiting,' get mapped. If you're having radiation or hormone therapy or thinking about getting a 'nerve-sparing' radical prostatectomy, get mapped. If TRUS doesn't show all the cancer that's present, you're not going to have the proper treatment," said Onik.

With 3-D transperineal mapping, a grid placed over the perineum (the area of skin between the rectum and the scrotum) allows an interventional radiologist to accurately map the location of each biopsy core removed. The cores are taken through the skin rather than through the rectum, allowing many more cores to be removed - about 50 compared to 10-12 in a TRUS biopsy. The mapping grid also allows the location of the tumor to be known much more precisely, allowing an interventional radiologist to cryoablate (freeze) only the tumor and not the whole prostate gland.

Controversy surrounds the treatment of prostate cancer, which usually grows slowly and initially remains confined to the prostate gland, said Onik. Growing evidence of overdetection and overtreatment in many men with low-risk tumors has led to a concept in the medical community of "watchful waiting" or observing a man's disease progression prior to initiating treatment. Many patients, however, feel uncomfortable with this strategy and may proceed to radical or aggressive treatment, said Onik. "When men must choose between 'watchful waiting' and high-morbidity whole-gland treatments (like surgery and radiotherapy), a lumpectomy-type treatment, which has so markedly changed the management of breast cancer for women, is a welcome 'middle ground' addition for those with prostate cancer," said Onik.

"Interventional cryoablation for prostate cancer is not experimental. This is a treatment option that doctors should discuss with their patients early on," emphasized Onik. Most people don't realize that you can surgically remove the whole prostate and, in 20 percent of the cases, the cancer can be left (called a positive margin), said Onik, who works in consultation with urologists. Doctors should discuss cryoablation with patients early on, he advised, noting that recently the American Urological Association issued a best practice statement that indicated that cryotherapy is an option for men who have clinically organ-confined prostate cancer of any grade with negative metastatic evaluation. Since this interventional treatment is not widely known to doctors and patients, individuals will need to pursue it on their own, he added.

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