Transurethral Microwave Thermotherapy, Transurethral Needle Ablation and Interstitial Laser Coagulation
TUMT to Treat BPH
In transurethral microwave thermotherapy (TUMT), a catheter inserted through the urethra delivers microwave energy that heats prostate tissue to temperatures above 113° F, causing death (coagulative necrosis) of prostate tissue. At the same time, a cooling system prevents damage to the surrounding tissue, particularly the urethra. TUMT requires only a local anesthetic, which is placed within the urethra.
TUMT is most appropriate for men with moderately sized prostates (30 to 100 g, approximately 1 to 3 oz) and moderate to severe symptoms (International Prostate Symptom Score of 12 or higher). Research shows that TUMT typically results in a 40 to 70 percent reduction in symptom scores.
In a five-year study comparing TUMT and TURP, researchers found no significant differences between the two techniques regarding improvements in symptoms, quality of life, peak urinary flow rate, residual urine volume, or prostate volume. However, more men treated with TUMT required additional treatment10 percent versus 4 percent of those who underwent TURP.
Side effects from TUMT are usually minor and generally disappear with time. TUMT is less likely than TURP to cause bleeding or sexual dysfunction, but it is associated with a higher risk of urinary tract infection. These infections usually result from catheterization, and the longer the catheter is in place, the higher the risk. Men undergoing TUMT usually have a catheter in place for two to 14 days. Antibiotics are often prescribed either after the procedure or after catheter removal to reduce the risk of infection. Other side effects of TUMT include short-term incontinence and urinary retention.
Transurethral needle ablation (TUNA) and interstitial laser coagulation (ILC)
With TUNA and ILC, tiny needles are advanced through the urethra to deliver radiofrequency energy (TUNA) or laser energy (ILC) to the prostate tissue. Men with larger prostates may require several needle punctures.
One advantage of these two approaches is that the surgeon can target specific areas of the prostate; other minimally invasive therapies deliver heat to the entire gland. However, both TUNA and ILC usually require intravenous sedation in addition to local anesthesia.
In a randomized trial reported in The Journal of Urology, investigators compared TUNA with TURP. They found that the treatment benefits of both procedures were maintained at five years. TUNA, however, was associated with fewer complications. For example, ED occurred in 3 percent of TUNA patients compared with 21 percent of TURP patients. In addition, none of the TUNA patients experienced retrograde ejaculation compared with 41 percent of the men who underwent TURP. TUNA patients were also less likely to experience incontinence or to develop urethral strictures.
The American Urological Association describes the ideal candidate for TUNA as a man with obstructive BPH, a prostate volume of 60 g (about 2 oz) or less, and prostate enlargement predominantly in the lateral lobes (the main lobes on either side of the urethra).
Concerning ILC, one multi-center trial demonstrated a 60 percent improvement in symptom scores with the procedure and a major complication rate of less than 2 percent. Catheterization was required for an average of five days after the procedure. In a review of randomized trials comparing ILC and TURP, improvement in symptom scores ranged from 59 to 68 percent with laser procedures and 63 to 77 percent with TURP. Men who underwent a laser procedure had shorter hospital stays and were less likely to require transfusions or to develop urethral strictures, but they were more likely to require a second procedure. The American Urological Association maintains that studies to date have shown limited long-term benefits for ILC.