NONSURGICAL TREATMENTS FOR BPH: MICROWAVE THERAPY
In microwave therapy, energy is delivered by an antenna inside a catheter, which can heat prostate tissue over a period of time, allowing a more normal flow of urine. It is still debatable as an effective treatment for BPH.
There are several types of equipment in use or being developed to deliver heat to the prostate gland in order to slowly shrink the enlarged gland without damaging the surrounding tissue.
A heat-generating microwave machine called the Prostatron has been used extensively in France (where it was developed) and in England. Since 1991, it has been used to treat over 30,000 patients. The machine costs around a quarter of a million dollars and consequently is not something you can expect to find in a urologist's office.
With the Prostatron method, first the size of the patient's prostate gland is evaluated. Then a treatment catheter with a tiny internal antenna is inserted into the urethra and positioned at the center of the prostate with a small ultrasound probe. The Prostatron heats the prostate gland while a cooling system keeps the urethra from being damaged. The unwanted tissue is destroyed by the microwave heat and slowly absorbed by the body over the course of a few weeks.
By this time, the tissue should shrink so that the urine can flow freely. Retrograde ejaculation, a problem associated with surgery and other forms of treatment, is not likely to result.
Physicians at the Prostate Unit in the Department of Urology of Charing Cross Hospital in London, England, recently reported their results using the Prostatron. The average patient was sixty-seven years old and had significant symptoms of prostate enlargement, such as urine retention and obstruction of the urethra. Some of the men were given a fake treatment, while the others received microwave therapy.
Those treated with the Prostatron had a 70 percent decrease in symptoms, a 53 percent increase in urinary flow rate, and a 92 percent decrease in the residual urine in the bladder after urination. For the men in the control group, there was no real improvement.
One complication noted was a 22 percent increase in acute retention of urine in the microwaved group that was limited to the immediate posttreatment period. One patient continued to have posttreatment retention that had not resolved in ten days, and he decided to go for surgery.
A six-month study of 150 men aged forty-three to eighty-three with enlarged prostates at five medical centers in 1991 produced overall favorable results with the Prostatron. Although 36 percent of the patients required urinary catheterization, all were free of the catheters by the six-week follow-up. Researchers concluded that the study demonstrates the safety, effectiveness, patient tolerability, and durability of transurethral microwave thermotherapy. Retrograde ejaculation or sexual dysfunction were rare side effects of the therapy.
Dr. Joseph E. Oesterling of the University of Michigan compared the effectiveness of three methods of increasing urine flow and found the following: drugs increase the urine flow by up to 2 millimeters per second; the Prostatron increases it by 4 millimeters per second, and surgery increases urine flow by 6 millimeters per second. Based on this, Oesterling believes the device may indeed fill that gray zone between drugs and surgery.
Transrectal Microwave Thermal Therapy
This method involves inserting a microwave probe into the rectum to destroy the prostate tissue that is obstructing the flow of urine. The destroyed tissue is then carried off via the urine. A definite advantage of this over the TURP is that it can be performed on an outpatient basis. It requires only a local anesthetic.
One disadvantage is that in order to destroy the targeted prostate tissue without impairing the adjacent structure, it is necessary for the patient to have three to ten low-dosage treatments. This does not appeal to most patients, who generally prefer a one-time procedure. Urologists generally recommend transurethral microwave thermal therapy as a more effective and convenient treatment.