Prostate cancer patients are talking about TULSA-PRO, but they don’t mean Tulsa, Oklahoma. TULSA stands for Transurethral ULtraSound Ablation, and PRO refers to its use in the PROstate gland. It is an MRI-guided minimally invasive procedure for the treatment of prostate cancer (PCa).

It works by directing ultrasound energy to ablate (destroy) prostate tissue. It is “transurethral” because the doctor inserts a slender ultrasound applicator into the prostate by passing it through the tube (urethra) that carries urine out of the body. A key factor in the success of the treatment is Magnetic Resonance Imaging, or MRI. In fact, the treatment is performed inside the bore (tunnel) of the MRI magnet. Thus, real-time MRI provides four key elements:

• ✓ Identifying the target tumor
• ✓ Planning treatment tailored to the patient’s tumor and prostate anatomy
• ✓ Monitoring the treatment in real time
• ✓ Confirming the zone of ablation at the end of the treatment.

As described by the Yale School of Medicine, “dynamic temperature feedback control over the intensity of the ultrasound beams and rotation of the Ultrasound Applicator can shape the pattern of thermal coagulation [heat-based tissue destruction] accurately and precisely in the prostate gland.”

How is TULSA-PRO different from HIFU?

Like its cousin High Intensity Focused Ultrasound (HIFU), sonic energy is used to generate lethal heat in the targeted zone. However, the delivery direction is different between the TULSA-PRO and HIFU. With TULSA, the applicator is centrally located within the gland itself, so patients often describe it as an inside-out treatment. This distinguishes it from transrectal HIFU, in which the ultrasound is beamed at the target from behind the gland through the rectal wall.

Is TULSA-PRO FDA approved?

In November, 2019, researchers announced the results of a pivotal trial called TACT, during which 115 men had whole-gland TULSA for localized PCa and were followed for one year. Based on favorable results (safety and effectiveness) the FDA cleared the device for the thermal ablation of prostate tissue, and the procedure became available to U.S. patients.

What does the research say about the treatment since then?

Although we don’t yet have long-term data, TULSA-PRO results are promising and likely to improve even more.

• The original TACT study demonstrated mentioned had a primary endpoint of PSA reduced by at least 75% after treatment, and 96% of patients achieved that goal. At 12 months, 75% of patients who were potent at baseline had regained potency—but it’s important to keep in mind that whole-gland ablation results in less post-treatment potency than focal treatment which can avoid damage to the neurovascular bundles.
• In 2022, Dora et al. reviewed data on 224 cases (10 studies of whole-gland or focal TULSA-PRO, up to 5 years followup). Salvage rates for PCa recurrence after one treatment ranged from 7- 17%. Continence rates were 92-100%, and potency rates were 75-98%.^[i]
• Longer-term results presented at the 2023 Annual Meeting of the American Urological Association reinforced the promise of TULSA-PRO. According to a press release, “Presentations reinforce the safety, efficacy and durability of the TULSA procedure, further supporting its potential as a mainstream, whole gland or focal treatment for prostate disease.” One particular presentation gave 4-year followup of the TACT study: a) 84% had needed no additional treatment for PCa, b) 87% of previously potent patients reported potency, and c) 94% had pad free urinary continence.

MRI-guided ultrasound procedures tend to have higher rates of cancer control than ultrasound-guided procedures like TRUS-guided HIFU due to the advantages of MRI as a superior guidance method, and that better cancer outcomes “may justify the additional costs associated with MRI guidance.”^[ii]

Perhaps one researcher summed it up best. At the 2023 AUA meeting, Dr. Rolf Muschter of Bielefeld, Germany’s ALTA Klinik presented his institution’s TULSA-PRO experience with 180 patients. Their patients were mixed, with primary or recurrent PCa, and a small group of them also had urinary problems due to BPH in addition to PCa. At the time of follow-up, 88% had no sign of recurrence, and of the men with BPH, 85% had relief from their urinary symptoms. 98% reported pad-free continence, while 100% of potent patients preserved their sexual function. Dr. Muschter remarked, “This real-world outcome study is the largest single cohort presented to date. The compelling results demonstrate that lesion-targeted TULSA is associated with promising mid-term oncological outcomes and a minimal functional side-effect profile, with the flexibility to treat localized prostate cancer in a primary, salvage, or concurrent setting of BPH through a patient-tailored whole-gland or lesion-targeted approach.”^[iii]

At the Sperling Prostate Center where we offer MRI-guided TULSA-PRO, we share Dr. Muschter’s enthusiasm. It’s no wonder that TULSA-PRO is promising, with more good results to come.

NOTE: This content is solely for purposes of information and does not substitute for diagnostic or medical advice. Talk to your doctor if you are experiencing pelvic pain, or have any other health concerns or questions of a personal medical nature.

References

[i] Dora C, Clarke GM, Frey G, Sella D. Magnetic Resonance Imaging-Guided Transurethral Ultrasound Ablation of Prostate Cancer: A Systematic Review. J Endourol. 2022 Jun;36(6):841-854.
[ii] Alabousi M, Ghai S. Magnetic resonance imaging-guided ultrasound ablation for prostate cancer – A contemporary review of performance. Front Oncol. 2023 Jan 4;12:1069518.
[iii] Profound Medical Group. “TULSA Procedure Featured in the Scientific Program at the American Urological Association 2023 Annual Meeting.” Press release issued May 1, 2023.