In the latest approach, which is performed with the patient under epidural anesthesia, two laser fibres are introduced transurethrally on either side of the prostate inside a stiff tube. A catheter with circulating cold water is inserted into the urethra to keep it cool. Then the patient is put in a standard MRI scanner, and the surgeon powers up the lasers and carefully watches the heat ball grow on a colour-coded display, making adjustments to ensure it encompasses the prostate but doesn't expand into surrounding tissue. No one really knows what the lethal dose is but we're working on the assumption that we have to get between 55 C and 60 C probably for one to two minutes. At the end of the procedure, the prostate is a shrunken mass of dead, coagulated tissue.
Patients can go home the next day, and are then followed up for evidence of tumour regrowth.
In contrast, the typical hospital stay after radical prostatectomy is about a week. They're looking for five men with prostate cancer who have failed conventional therapy and whose prostates aren't so large that they partly fall outside the range of the laser fibres. So far, recruitment is going slowly. Dr. Trachtenberg believes thermal ablation is more promising than cryosurgery for prostate cancer, which he said many surgeons have abandoned because of excessive complication rates. So I thought if we're going to do something, we might as well try to go for the gold.