# Design of Noninvasive Therapies Utilizing Nonlinear Focused Ultrasound With Shocks

> **NIH NIH R01** · UNIVERSITY OF WASHINGTON · 2020 · $619,430

## Abstract

PROJECT SUMMARY
Renal carcinoma (RCC) and hepatocellular carcinoma (HCC) are two of the most common abdominal solid
organ malignancies in the US, accounting for nearly 100,000 combined new cases and nearly 40,000 deaths in
2015 [Siegel 2015]. With recent imaging advances leading to early diagnosis, medical practice is shifting
toward the use of minimally invasive focal therapies (e.g., radiofrequency ablation, cryotherapy) for treating
tumors. However, these treatments possess limitations: They require invasive deployment and rely on thermal
effects that are poorly controlled, especially near vascular structures that can act as heat sinks. In addition,
real-time treatment monitoring capabilities are minimal because thermal lesions are not easily visualized on
standard imaging techniques. High intensity focused ultrasound (HIFU) offers an alternative focal therapy
that can be delivered noninvasively. At present, clinical HIFU treatments involve thermal ablations that are
subject to these same limitations; however, boiling histotripsy (BH) is a noninvasive HIFU modality recently
invented by our group that can potentially overcome these limitations by delivering high-amplitude shock
waves to mechanically ablate tissue. BH has many potential clinical advantages over existing focal
therapies, including thermal HIFU: 1) generation of precise, controllable lesions with sharp margins while
sparing critical structures; 2) targeting and real-time monitoring of treatments through ultrasound-based
imaging, which utilizes the strong acoustic reflectivity of bubbles; and 3) potentially faster resorption of liquefied
BH lesions. In previous years of NIH support, we have developed metrology tools for characterizing HIFU fields
with shocks, invented the BH method and elucidated its physical mechanisms, identified effective pulse
sequences, implemented real-time B-mode imaging of treatments, and designed a HIFU array optimized for
abdominal BH applications. However, two scientific challenges remain in order to reliably deliver safe and
effective BH treatments in humans: First, the impact of tissue inhomogeneities on shock formation is not yet
quantitatively understood. Second, dose metrics and corresponding treatment strategies have not been
defined and validated for ablating tissue volumes comprising multiple target sites. The first two aims in this
project seek to address these challenges by 1) extending our nonlinear metrology tools to include modeling in
heterogeneous tissues to predict in situ shock formation, and 2) conducting experimental studies in ex vivo
liver and kidney tissue to determine dose metrics for use in designing volumetric BH treatments. The third aim
involves the performance of rigorous pre-clinical studies using a prototype system to treat in pig kidney and
liver in vivo. Successful completion of these aims will aid the design and execution of BH treatments,
providing the framework needed to conduct clinical trials for RCC and HCC. Beyond t...

## Key facts

- **NIH application ID:** 9974517
- **Project number:** 5R01EB007643-12
- **Recipient organization:** UNIVERSITY OF WASHINGTON
- **Principal Investigator:** Vera Khokhlova
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2020
- **Award amount:** $619,430
- **Award type:** 5
- **Project period:** 2008-09-15 → 2022-06-30

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/9974517

## Citation

> US National Institutes of Health, RePORTER application 9974517, Design of Noninvasive Therapies Utilizing Nonlinear Focused Ultrasound With Shocks (5R01EB007643-12). Retrieved via AI Analytics 2026-05-24 from https://api.ai-analytics.org/grant/nih/9974517. Licensed CC0.

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