Dr George on Early Insights and Future Directions for Water Vapor Thermal Therapy in Prostate Cancer

“This study revealed the massive potential of this technology if we can maintain the same results, both in a greater number of patients and with men who are followed for a longer period.”

Arvin K. George, MD, director of Prostate Cancer Programs and an associate professor of clinical urology at Johns Hopkins School of Medicine, discussed the mechanism of water vapor thermal therapy and the clinical implications of findings from the VAPOR 2 study (NCT05683691) presented at the 26th Annual Meeting of the Society of Urologic Oncology.

He explained that although several prostate-directed treatments rely on thermal energy for tissue destruction, water vapor therapy is distinct in the way heat is delivered to cancer cells. George noted that conventional thermal ablation modalities—such as radiofrequency ablation or high-intensity focused ultrasound—primarily rely on conduction, in which heat is transferred gradually through tissue, much like heating a pot of water. In contrast, water vapor thermal therapy relies on convection, which occurs when water transitions from a liquid to a gaseous state and releases a rapid burst of thermal energy, he stated. When vapor is injected into prostate tissue using the Vanquish system, the phase shift releases energy over just a few seconds, resulting in rapid and efficient cellular destruction, he reported. Each ablation cycle lasts approximately 10 seconds, according to George.

Early evidence, including the results of VAPOR 2, has demonstrated that vapor-based thermal ablation can effectively destroy targeted prostate tissue and appears safe within a small cohort of patients over a relatively short follow-up period, George summarized. In this study, water vapor therapy was evaluated in men with Gleason 3 + 4 prostate cancer, showing successful ablation with a favorable safety profile, he continued. George emphasized that these findings reveal the potential for water vapor therapy to serve as a minimally invasive focal treatment option for appropriately selected patients.

The clinical implications of VAPOR 2 extend to several future research directions, George added. He highlighted that, if durable outcomes are sustained in larger populations and with longer follow-up, water vapor therapy could become an alternative focal modality alongside cryotherapy, HIFU, and electroporation. Additionally, the current data enable exploration of broader clinical indications, he noted. Future studies may evaluate whether therapy can be safely extended to men with Gleason 4 + 3 disease, who have higher-risk histologic features, he said. Other potential applications include salvage therapy for patients who have previously received radiation and subsequently developed localized recurrence—an exclusion criterion in the initial study, he spotlighted. George concluded that the VAPOR 2 results establish an early foundation for expanding the use of convection-based thermal ablation.