MRI-Guided Transurethral Ultrasound Ablation to Treat Prostate Cancer Studied in 5-Year Follow-Up Data

March 20, 2024—Transurethral ultrasound ablation (TULSA) guided by MRI was shown to be an effective alternative to surgery or radiation in treating prostate cancer in 5-year follow-up data from a study conducted by Steven S. Raman, MD, et al.

Surgery or radiation, the traditional treatment options, have a risk of side effects (including urinary incontinence and erectile dysfunction) that cause significant morbidity and adverse lifestyle effects. The investigators stated that for some patients, TULSA is a durable, whole-gland treatment that does not preclude future treatment with surgery or radiation.

The Society of Interventional Radiology (SIR) announced that the findings will be presented as Abstract #135 at SIR 2024, the society’s annual scientific meeting held March 23-28 in Salt Lake City, Utah.

“The success of TULSA represents a revolution in whole-gland treatment for prostate cancer,” commented Dr. Raman in the SIR press releases. “Prostate cancer is the most common form of cancer in men, affecting one in eight men in their lifetimes. We have more research to do, but if validated, TULSA has the potential to change the standard of care for thousands of men.” Dr. Raman is Professor of Radiology, Urology, and Surgery at the David Geffen School of Medicine at UCLA in Los Angeles, California.

According to Dr. Raman in the SIR press release, the study affirms that interventional radiologists now have a meaningful role in detection and management of prostate cancer care as they already had in other types of cancer, such as lung, kidney, and liver cancers. He said interventional radiologists’ expertise in imaging and image-guided procedures and experience with ablation make them a critical part of the prostate cancer care team.

As summarized in SIR’s press release, the TULSA procedure involves a small, catheter-like device inserted through the urethra into the prostate. MRI is then used to guide precise positioning of 10 therapeutic ultrasound elements into the prostate. MR thermometry is used to monitor the tissue while heating to > 55° within the prostate and limiting heat to the sensitive nerves surrounding the prostate as the device rotates around the entire gland. The procedure can be performed in an outpatient or inpatient facility under general or spinal anesthesia in 2 to 3 hours.

Dr. Raman explained in the SIR press release, “This image-guided therapy maximizes our ability to kill cancer cells while minimizing collateral damage to the prostate to achieve the ultimate trifecta in prostate cancer treatment: full local cancer control while maintaining urinary continence and potency. The latter are the complications of most prostate cancer therapies that patients hate and often result from a lack of precision in treatment monitoring.”

According to the SIR press release, patients in the prospective observational study showed improvement in the reduction of presence of cancer, prostate size, and prostate-specific antigen levels (PSA).

Cancer was undetectable on follow-up biopsy by 76% at 1 year after TULSA, with a decrease in median prostate volume by 92% within 1 year and a decrease in PSA from 6.3 to 0.63 ng/mL at 5 years.

Additionally, TULSA had a very favorable side-effect profile compared to alternative surgical, radiation, and thermal therapies (ultrasound-guided high-intensity focused ultrasound, cryotherapy), showing that 92% of patients recovered continence and 87% preserved erectile function by 5 years.

Investigators in the study enrolled 115 men at 13 sites in five countries. Of those treated patients, 25 men received follow-up conventional treatment with surgery or radiation because of residual or new tumors. Through this process, the investigators discovered early predictors of TULSA failure related to calcifications between the urethra and the target prostate cancer and learned better monitoring of prostate swelling, targeting, and misalignment, leading to improved detection and management of these preventable errors during the procedure, reported SIR in the press release.

The research into TULSA’s effectiveness continues with the CAPTAIN randomized controlled trial comparing TULSA with radical prostatectomy, noted the SIR press release.