Immune-Boosting Effects of Histotripsy Extend to Cancer Cells Outside the Liver

The non-invasive liver tumor treatment known as histotripsy, which was approved by the FDA in late 2023, has been in use at University of Michigan Health beginning in early 2024. As histotripsy gains wider adoption across Michigan and neighboring states, U-M researchers are closely monitoring how the body’s immune system responds to the treatment.

Anutosh Ganguly, Ph.D., an assistant research scientist at U-M Health, is leading a team focused on advancing the understanding of immune responses triggered by histotripsy in liver cancer. Their goal is to explore how these responses might apply to other tumor types, including pancreatic cancer and melanoma.

Developed by biomedical engineers at U-M, the histotripsy technology uses ultrasound waves to destroy liver tumors without the severe side effects typically associated with chemotherapy or radiation.

According to Ganguly’s team, the immune-stimulating effects of histotripsy appear to be linked to a reduction in tumor hypoxia—a condition of extremely low oxygen levels within the tumor. After histotripsy treatment, these low oxygen levels are no longer present. The relief from hypoxia after histotripsy treatment facilitates a rise in anti-tumor CD8+ T cells that move to the site of the procedure but also to the distant tumors within other parts of the body to oppose their growth. In addition to physically destroying tumor cells, histotripsy stimulates the patient’s immune system to fight cancer more effectively throughout the body.”

Understanding that histotripsy treatment can alter how the body reacts to cancer cells located outside the liver gives better insight into how metastases in other areas of the body may respond to direct histotripsy treatment.

“The additional effect of activating the patient’s own immune system against cancer cells by histotripsy can help the patient’s body respond better to other types of cancer treatment they may be receiving in addition to the histotripsy, such as radiation and chemotherapy,” said Ganguly.

“Our work to continue understanding the ways that histotripsy impacts the whole body can open doors for new and potentially more effective ways to treat cancer that have fewer patient side effects.”

Ganguly and his team plan to continue their research to better understand how histotripsy affects cancer cells throughout the body, influences the patient’s immune system, and what additional therapies might improve its effectiveness.