The energies that make up Magnetic Resonance Imaging are basically a magnetic field and radio waves. In their natural form, neither can be seen by the human eye. Likewise, sonic energy or sound waves are also invisible to the human eye, though at certain frequencies the human ear picks them up and the brain makes sense of them. Together, these three energy forms can be converted into invisible “tools” that can penetrate the body in controlled ways, and permanently alter physical structures within it.

MRI-guided Focused Ultrasound Destroys Prostate Cancer Tumors

The Sperling Prostate Center is one of nine medical centers participating in a clinical study titled “Focal MR-Guided Focused Ultrasound Treatment of Localized Intermediate Risk Prostate Lesions.” We are very excited about the use of non-radioactive focused ultrasound beams, guided by real-time MRI scans, to target focal prostate tumors and instantaneously destroy them.

We are already renowned for our pioneering clinical application of Focal Laser Ablation (FLA), which is accomplished by piercing the core of a prostate tumor with a thin laser optic fiber, inserted under real-time MRI guidance. When the laser is activated, the globe of heat it generates at the tip when it encounters tissue is monitored for temperature and size using special MRI software called thermometry. Afterward, another scan confirms the zone of successful ablation.

Now, it’s even more exciting to think of beams of sound energy achieving the same purpose, guided and monitored by real-time visualization and temperature feedback, without having to physically pierce tissue. MRI-guided Focused Ultrasound (MRgFUS), delivered by means of a transrectal ultrasound wand, is almost like magic! Prostate cancer is not the only disease condition that can be treated using MRgFUS. The Focused Ultrasound Foundation states that as of 2019, there are 136 conditions amenable to MRgFUS, which is used annually all over the world with thousands of patients.^[i]

Canadian study publishes results of MRgFUS study

The results of our study here in the U.S. are not yet published, but a team of Canadian clinicians has just published the early results of their Phase II trial of MRgFUS with 44 prostate cancer patients.^[ii] Among the patients, 36 had Grade Group (GG) 2 while 8 had GG 3 disease. At 6 weeks after treatment, follow-up consisted of standardized questionnaires on urinary and sexual function; at 5 months, the questionnaires were again administered, as well as a targeted biopsy into the zone of ablation.

Findings were as follows:

• There were no major adverse effects
• At 5-month biopsy, 93% of the men treated were free of clinically significant prostate cancer at the treatment site
• Average urinary and sexual function scores were similar at baseline and 5-month follow-up
• Larger ablation zones were linked with decline in urinary and sexual function scores at both follow-up intervals

The authors concluded, “Targeted focal therapy of intermediate-risk prostate cancer performed with MRI-guided focused ultrasound ablation was safe and had encouraging early oncologic and functional outcomes.”^[iii]

Enthusiasm over MRgFUS

We anticipate a wave of enthusiasm on from both doctors and patients as more research results become available. There is no doubt that both prostate MRI and focal therapy have transformed diagnosis and treatment for qualified patients who shy away from the idea of radical surgery or radiation, yet are not sold on Active Surveillance for their own peace of mind. The ability to offer a treatment that does not involve incisions or punctures, and that is guided by an imaging/monitoring method superior to ultrasound, best serves patients who are seeking such an approach, and equally serves doctors who want confidence that the treatment offers excellent cancer control as well as patient quality of life.

The Sperling Prostate Center looks forward to a favorable analysis of data from our own study, and for the day when it is published.

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] 2020 State of the Field Report, Focused Ultrasound Foundation. http://www.fusfoundation.org/images/pdf/Focused_Ultrasound_Foundation_2020_State_of_the_Field_Report.pdf
[ii] i Ghai S, Finelli A, Corr K, Chan R et al. MRI-guided Focused Ultrasound Ablation for Localized Intermediate-Risk Prostate Cancer: Early Results of a Phase II Trial. Radiology. Published online Feb. 2, 2021. https://doi.org/10.1148/radiol.2021202717
[iii] Ibid.