Post-TUMT symptom improvement persists long term

September 1, 2005

San Antonio--Five-year follow-up data from the original FDA trial cohort demonstrate that transurethral microwave thermotherapy (TUMT) using the TherMatrx TMx-2000 (American Medical Systems, Minnetonka, MN) provides durable, safe treatment for men with symptomatic BPH. Study findings were presented by David M. Albala, MD, at the AUA annual meeting here.

The trial, conducted at seven centers, randomized 200 men with BPH-related cystoscopic bladder outlet obstruction 2:1 to TUMT or sham treatment. After 3 months, the sham patients were crossed over into the treatment arm.

The patients enrolled in the FDA trial had to be off any existing medical therapy for BPH for at least 30 days and fulfill the following criteria: peak flow rate <12 mL/sec, AUA SI >12, postvoid residual urine <250 cc, and no "ball-valve"-type median lobe involvement.

One hundred fifty-six men were evaluable at 1 year. Data from those patients showed approximately 50% improvements from baseline in mean AUA SI (21.4 to 12.4), mean bother score (17.1 to 9.3), and mean quality-of-life score (10.8 to 6.1). Data on peak flow rate were available for 111 men at 1 year and showed nearly 60% improvement from baseline (8.6 to 13.6 mL/sec).

Dr. Albala also observed that the safety in this study cohort has been excellent over time, and that this experience mirrors the safety profile of the TherMatrx TMx-2000 in clinical use.

"More than 40,000 procedures have been done in the U.S. with this device, and there have never been any significant complications, including tissue injury, strictures, fistula formation, or incontinence," he said.

Dr. Albala noted that thermotherapy with the TMx-2000 is dose-optimized and is performed at a lower wattage than other transurethral microwave systems. Therefore, only the periurethral tissue adjacent to the catheter is targeted during the TherMatrx TMx-2000 procedure.

"Other systems operate at higher energy and use a cooled catheter so that the energy is transferred deeper into the prostate," Dr. Albala said. "There have not been any direct comparative studies, but it seems that success rates are similar across all systems, whereas only the TherMatrx TMx-2000 has not been associated with any tissue injury-related complications."

Dr. Albala was an investigator in the FDA clinical trial, but he has no financial interest in the TherMatrx TMx-2000 or American Medical Systems.