Medical Research

The Vanquish Water Ablation System

A novel prostate cancer treatment

BY Christopher Dixon, MD

For decades, the primary approaches for treating prostate cancer have been radical prostatectomy or radiation therapy. Recent years, however, have seen a mounting consensus that these aggressive treatments may amount to overtreatment for many men because of the significant risk of life-altering side effects such as urinary incontinence (UI) and erectile dysfunction (ED).

Approximately 90% of prostate cancer diagnoses involve cancer localized to the prostate gland (clinically localized disease). Patients are categorized into one of six risk groups based on prognosis: very low, low, favorable-intermediate, unfavorable-intermediate, high, and very high risk. Radical therapy is typically unnecessary for individuals with “very low” and “low” risk diseases, leaving active surveillance the most commonly recommended management strategy for this demographic. For higher-risk groups, radical therapy remains the preferred treatment.

Men in the middle of the risk spectrum, those with clinically localized “intermediate” risk disease, face the challenging decision of balancing the risk from prostate cancer with the risk to their quality of life. Their cancer is deemed clinically significant but not immediately life threatening. According to 2023 National Comprehensive Cancer Network (NCCN) guidelines, both active surveillance and radical treatment are appropriate options for intermediate-risk disease, leaving these patients grappling with the tough choice between the two extremes of active surveillance and radical treatment.

One in eight men will confront a prostate cancer diagnosis during his lifetime.

A pressing need exists for a therapeutic approach that bridges the gap between these two options by actively managing the disease while minimizing adverse quality-of-life side effects.

A Novel Approach

Minnesota-based Francis Medical has introduced an innovative approach to prostate cancer treatment that capitalizes on the energy released when sterile water vapor (steam) returns to its liquid state. Its water vapor ablation system, Vanquish™, deploys vapor to target cancerous regions within the prostate while safeguarding nerves and other surrounding structures, thereby reducing the likelihood of undesirable treatment side effects.

The process begins when water is heated, with energy added at a rate of 1 calorie per gram for every 1°C increase in temperature. This process continues until the temperature reaches 100°C (when water transitions from liquid to vapor), generating the latent heat of vaporization, which contains more than five times the energy (540 calories) per gram compared to its liquid state. Vanquish uses this energy to kill the cancerous prostate tissue.

During the ablation procedure, sterile water is converted to vapor and delivered through a needle-shaped catheter with a porous distal tip placed within the targeted tissue. Prostate cells are surrounded by interstitial fluid-filled spaces. In 10-second treatments, vapor exits the catheter at a higher pressure than the extracellular environment, moving convectively through prostatic tissue, displacing interstitial fluid, and reaching cell membranes. Rapid phase transformation of water vapor back to its liquid state (condensation) releases the stored latent heat of vaporization directly onto the affected cell membranes, denaturing them and causing cell death.

An essential characteristic of water vapor is its ability to respect the natural boundaries of the prostate. During treatment, vapor pressure is sufficient to expose cell membranes but insufficient to penetrate denser tissues like the prostatic capsule and pseudo-capsule, effectively preserving them as physical barriers. Unlike conductive energy methods, vapor conforms to the prostate’s anatomy, optimizing thermal dose delivery to the targeted tissue and minimizing damage to nerve bundles and surrounding structures. Convective heat transfer uniformly delivers thermal energy throughout the treatment region, unlike conductive ablation modalities that create thermal gradients.

Day of the Procedure

The Vanquish product is in the pre-market approval phase and not yet available commercially. For patients currently being treated in clinical studies, the procedure is conducted on an outpatient basis at a hospital or ambulatory surgery center under general anesthesia. Pretreatment multiparametric MRI (mpMRI) and a prostate biopsy pinpoint the desired ablation location. The primary treatment plane, intersecting the target lesion, is determined using measurements from mpMRI sequences. A comprehensive treatment plan is then devised, allowing for overlapping treatments within the target, distal and proximal planes to encompass the entire lesion plus the desired margin.

The Vanquish water vapor ablation system includes a custom cart housing a generator, a monitor and an extendable arm for positioning the monitor directly over the patient. The monitor displays live ultrasound and cystoscopy images, pertinent treatment data and electromagnetic tracking tools aiding in navigation of the prostate. A proprietary stabilization system supports the ultrasound probe and treatment device, offering full freedom of motion when disengaged and enabling hands-free operation when locked in place.

The procedure involves transurethral delivery of the treatment device into the prostatic urethra, conducted under cystoscopy visualization. The device is subsequently rotated to the desired treatment angle, and a needle-shaped catheter is advanced through the prostatic urethra to the chosen treatment area within the prostate. Advancement of the vapor needle is visualized under transrectal ultrasound (TRUS), aided by an electromagnetic tracking system that overlays visual targeting tools onto live ultrasound images. Additionally, bio-capacitance sensors on the needle tip inform the user as the needle approaches the prostate capsule.

Once the treatment needle is delivered to the target tissue, individual 10-second vapor treatments are administered, generating a clear hyperechoic effect under TRUS. A single treatment creates a 1 ½ to 2 cm diameter ablation volume in unobstructed tissue. However, due to vapor’s constrained movement dictated by the prostate’s natural anatomy, the treatment volume is evenly distributed within the confines of the zone it is delivered to. Individual treatments are spaced approximately 1 cm apart, creating an overlapping effect until the complete ablation of the target lesion plus the desired margin is achieved.

The procedure is conducted on an outpatient basis.

Postprocedure, patients typically go home the same day, report minimal pain and can often resume normal activities as early as the following day. Vanquish clinical study protocols recommend retaining a catheter for at least three days, but earlier removal is possible. Water vapor therapy also allows for retreatment or additional treatments if new cancer is detected later. It also keeps the option open for more radical therapy if needed.

An Accelerated Path to Commercialization

Water vapor has already been proven safe and effective for treating benign prostatic hyperplasia (BPH) and is commercially available as Rezūm, owned by Boston Scientific. Following Boston Scientific’s acquisition of Rezūm technology from NxThera, the founding company, a spinoff company, Francis Medical, was established to explore water vapor’s potential in urological cancer treatments. Initially, the company’s focus lies in addressing prostate cancer followed by bladder and kidney cancer.

Founded in 2018, Francis Medical is privately held and headquartered in Maple Grove, Minnesota, with 35 full-time employees. It is a tribute to and legacy of the inventor’s father, Francis Hoey, who endured prostate cancer treatments that had harsh implications on his everyday living before the disease took his life in 1991. The company embodies a strong, purpose-driven culture centered around a shared mission encapsulated in its tagline, “Tough on cancer. Gentle on patients.”

To date, the company has secured $80 million in funding for the ongoing development and execution of clinical studies to obtain U.S. regulatory approval by late 2025, closely followed by international approvals. The company recently announced receiving Breakthrough Device Designation from the FDA. This designation expedites the review of innovative technologies that promise more effective treatment or diagnosis of life-threatening or irreversibly debilitating diseases or conditions. To qualify for Breakthrough Device Designation, a device must demonstrate the potential for superior treatment compared to existing standards of care.

“Our goal is to become the first-line therapy of choice for patients with prostate cancer,” said Michael Kujak, president and CEO. “We are excited that the FDA has recognized the potential of our technology to be a breakthrough for patients who today face the difficult choice between addressing their cancer and avoiding the debilitating morbidities often associated with current standards of care.”

Francis Medical is currently conducting its VAPOR 2 pivotal U.S. clinical study. VAPOR 2 is a prospective, multicenter, single-arm study designed to treat 235 patients with intermediate-risk, localized prostate cancer in up to 30 U.S. clinical sites. Three Minnesota sites have been chosen for participation: The University of Minnesota (Christopher Warlick, MD), Mayo Clinic (Lance Mynderse, MD), and Minnesota Urology (Aaron Milbank, MD). Researchers anticipate using the one-year follow-up data from the VAPOR 2 study to support an FDA submission for U.S. market clearance. Patients in VAPOR 2 will continue to be monitored for five years to gather long-term cancer outcomes. This pivotal study follows a 15-patient U.S. early feasibility study that demonstrated an excellent safety and efficacy profile, with 14 out of 15 patients being free of clinically significant cancer at the study’s conclusion.

Dr. Naveen Kella, of The Urology Place in San Antonio, Texas, treated the first patient in the VAPOR 2 study. “I am excited to participate in the VAPOR 2 study, and it is a great privilege to treat the first patient,” said Dr. Kella. “Currently, prostate cancer patients find themselves in the difficult position of balancing the oncological risks of the disease with the life-altering side effects that can often accompany traditional treatments. Water vapor therapy shows great promise to provide patients with another option to proactively manage their cancer risk while preserving quality of life.”

Francis Medical is working to establish Vanquish as the primary therapy of choice for treating prostate cancer for patients and their physicians. They are developing this simple water vapor procedure to offer a safe, effective and convenient method for ablating cancerous tissue within the prostate, all while safeguarding nearby nerves and other critical structures. This approach promises to deliver lifesaving cancer control while maintaining a high quality of life.

Although prostate cancer is currently the company’s primary focus, preliminary research shows excellent promise for applying water vapor therapy to bladder and kidney cancer. Francis Medical plans to shift resources to accelerate the development of these additional applications as the Vanquish system for prostate cancer transitions into commercial use.

“The vision that started this company and continues to drive us is to create a better experience for the patient,” said Michael Hoey, founder and chief technology officer. “Everyone in the company shares this vision, and we strive each day toward getting this life-altering therapy into the hands of urologists and their patients.”



Christopher Dixon, MD, is a urologist and chief medical officer at Francis Medical. He has contributed to the VA Cooperative Studies Program and received National Institutes of Health research grants.