Focal Therapy: Targeting Prostate Cancer with Fewer Risks

Focal Therapy: Targeting Prostate Cancer with Fewer Risks

Leading-edge technologies are fundamental to delivering the highest quality prostate cancer care. Across the board, faculty in the UW Medicine Department of Urology are dedicated to expanding the institution’s cadre of advanced tools.

“Urology is specialty that embraces new technologies that will move the field forward,” says George R.Schade, MD, a UW Medicine board-certified urologist and urologic oncologist. “It’s a great intersection of the scientific and human components of medicine. UW Medicine is an outstanding environment for this type of work.”

For Schade, strengthening that intersection means concentrating on focal therapy — a relatively new approach that minimizes adverse effects, including sexual dysfunction; urinary dysfunction including leakage, urgency, slow stream and nocturia; and changes in bowel function. It targets the diseased portion of the prostate, while sparing uninvolved areas to reduce collateral injury to surrounding structures. He devotes much of his clinical and research attention to improving how this treatment targets prostate cancer.

Improving therapy through research

“We have a vision for how we can treat patients in the future and minimize the impact that prostate cancer treatment will have on their lives,” he says. “We’re developing the next generation of technologies that will change how we deliver care.”  

To build on and improve current focal therapy treatments, Schade collaborates with engineers in the University of Washington Applied Physics Laboratory and the UW Center for Industrial and Medical Ultrasound. He and his team are working on two main projects:

• Improved high-intensity focused ultrasound (HIFU) technique: 

With funds from the National Institutes of Health, the team is developing an updated HIFU approach that delivers more precise treatment without producing heat. The technology uses boiling histotripsy — short, high-intensity energy pulses to produce vapor microbubbles in tumor tissue. The interaction between the microbubbles and the ultrasound waves liquifies and destroys the cancerous tissue.

“One millimeter of precision in prostate cancer treatment can be the difference between avoiding injury and causing incontinence or nerve bundle injury. This technology is more exact than existing focal therapies and, as a result, has the potential to further improve the side effects of focal therapy,” Schade says. “Additionally, boiling histotripsy offers treatment feedback not available with other focal therapies — the bubbles we generate are reflective on ultrasound imaging, so you can see the treatment happening and know exactly where in the prostate you’re treating. Further, this method also gives us real-time feedback on what tissue we’ve destroyed and what tissue we still need to destroy. These capabilities could help improve cancer control outcomes.” 

With NIH support, it’s anticipated that a clinical device will be ready for first-in-human trials within five years.

• Better prostate cancer visualization: 

Schade’s team is working on novel ultrasound imaging methods to be able to see tumors in the prostate at the time of focal therapy — currently treatments use fusion of prior MRI images to help direct treatment, but the tumor is generally not visible during the treatment itself. Enabling real-time tumor visualization at the time of focal treatment could significantly improve the targeting and accuracy of focal therapies. 

Schade says UW Medicine is the ideal environment for developing next-generation ultrasound technologies for prostate cancer care. 

“UW Medicine has always been a world leader in urology care,” he adds. “The hope now is that we’ll leverage our strong clinical background with our continually expanding ultrasound expertise to create more user-friendly, patient-friendly focal therapy systems.”

Additional targeted care that minimizes risks 

Irreversible electroporation (IRE) is another option the team utilizes for patients with localized prostate canceronce their disease progresses beyond active surveillance. IRE uses transrectal ultrasound guidance to place electrodes through the perineum into the prostate. Electric current then runs through the electrodes to create pores in the targeted cell membranes, leading to controlled cell death. The process doesn’t produce heat. But like HIFU, IRE is highly controllable and does not damage surrounding tissue outside the planned treatment area. 

Schade says UW Medicine will soon offer micro-ultrasound in addition to HIFU and IRE to help improve image guidance for prostate biopsies and focal therapy treatments. Micro-ultrasound uses shorter wavelengths to produce higher-resolution ultrasound images that are three times clearer than current ultrasound scans. These pictures can highlight individual prostate ducts and can visualize prostate cancer tumors that are generally not visible on standard ultrasound.

Identifying good focal therapy candidates

Schade says roughly 70% of patients come to him seeking focal therapy because the treatment is less intense with fewer negative impacts. 

“As long as we can get the whole tumor with focal therapy, we should be able to have similar success in eliminating cancer as with surgery and radiation, but clinical data is still early,” he says. “With respect to quality of life, the data is pretty convincing, showing the risk of life-altering sexual, urinary and bowel function changes is lower with focal therapy than with more invasive treatments.”

Schade notes that only 25% to 35% of patients are good focal therapy candidates. Active surveillance is still the appropriate option for patients with slow-growing cancer, while patients with aggressive cancers or those involving the majority of the prostate need more aggressive treatment. 

Individuals respond best to focal therapy when they have intermediate-risk cancer. Specifically, they should have unilateral cancer and a Gleason score — the measurement that grades the severity of their prostate cancer — of 7. 

By delivering advanced focal therapy to this patient population, UW Medicine continues to move the needle toward more effective, individualized prostate cancer care.