# Transrectal Histotripsy for Focal Ablation of Prostate Cancer

> **NIH NIH R01** · UNIVERSITY OF WASHINGTON · 2022 · $623,220

## Abstract

PROJECT SUMMARY
First line radical treatments for localized prostate cancer are associated with significant morbidity and side effects
impacting urinary, bowel, and sexual quality of life. As a result, there is strong interest in focal therapy in which
the cancer tissue is eradicated while sparing normal healthy prostate and adjacent structures (such as urinary
sphincter, rectum, and neurovascular bundles) in order to maintain oncologic outcomes while reducing side
effects. To date, clinically available focal therapies rely on thermal ablation (heating or freezing) to induce
coagulative necrosis and cell death. Presently, the most widely used thermal technique for focal therapy of
prostate cancer is transrectal high intensity focused ultrasound (HIFU). While existing data suggest that thermal
HIFU has less morbidity than radical treatments, its ability to effectively control cancer is still uncertain with series
reporting positive biopsies in up to 30-40% of patients within one year of treatment. Limitations of thermal HIFU
systems, including heat diffusion/sinking and minimal real-time treatment feedback, may explain efficacy
concerns. Our team has developed a HIFU-based method termed boiling histotripsy (BH) that uses sequences
of milliseconds long HIFU pulses with shock fronts to mechanically ablate targeted tissue to subcellular debris
without thermal effects and with real-time ultrasound imaging feedback. We have developed the first prototype
of a pre-clinical system and have demonstrated the feasibility of transrectal BH for non-thermal ablation of
prostate tissue in a canine model. The specific aims of this proposal are built upon the previous work to refine
BH technology into a clinically viable format for focal therapy of PCa. In Aim 1, a novel transrectal multi-element
array transducer will be developed and built facilitating efficient volumetric BH prostate ablation using electronic
steering and mechanical translation of the focus. The BH transducer will be combined with an imaging probe
and both will be controlled by a Verasonics Flexible Ultrasound platform. Comprehensive acoustic
characterization of the BH system will be performed, and BH treatment protocols will be designed accordingly
and evaluated in tissue phantoms and ex vivo prostate tissue. In Aim 2, improved ultrasound-based imaging
algorithms will be developed to enable pre-treatment tumor localization using shear wave elastography and
quantitative tissue liquefaction feedback using plane wave Doppler imaging. In Aim 3, the resulting BH array
system, exposure protocols, and imaging algorithms will be evaluated in a series of acute and chronic in vivo
studies in a canine model to demonstrate the safety and efficacy of the device. At the conclusion of the project
period, transrectal BH technology will be ready for submission to FDA for an Investigational Device Exemption
in preparation for future clinical trials.

## Key facts

- **NIH application ID:** 10366109
- **Project number:** 1R01CA258581-01A1
- **Recipient organization:** UNIVERSITY OF WASHINGTON
- **Principal Investigator:** George R Schade
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2022
- **Award amount:** $623,220
- **Award type:** 1
- **Project period:** 2022-09-23 → 2027-08-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10366109

## Citation

> US National Institutes of Health, RePORTER application 10366109, Transrectal Histotripsy for Focal Ablation of Prostate Cancer (1R01CA258581-01A1). Retrieved via AI Analytics 2026-05-21 from https://api.ai-analytics.org/grant/nih/10366109. Licensed CC0.

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