Ultrasound Imaging Non-Invasively Tracks Tumor Response to Radiation and Immunotherapy

A major challenge has been predicting and monitoring how individual tumors react to therapy, with the significant heterogeneity observed across patients complicating the process. Researchers have now identified a promising non-invasive method to track how tumors respond to radiation and immunotherapy, using the body’s own immune system to combat cancer. A groundbreaking study, published in Theranostics, shows how ultrafast power Doppler ultrasound (US) can offer valuable insights into the complex vascular interactions within the tumor microenvironment, potentially transforming personalized cancer treatment approaches.

An interdisciplinary research team from Vanderbilt University (Nashville, TN, USA) has developed an innovative method using ultrafast power Doppler ultrasound to monitor tumor vasculature in real-time in two breast cancer models—metastatic and non-metastatic. By tracking changes in blood vessel networks, the researchers can now gain unprecedented insights into how tumors respond to radiation therapy. The ultrasound measurements revealed a consistent decrease in the tumor vascular index following radiation therapy, which correlated with a significant infiltration of CD8+ T cells into the tumors. These T cells are essential for the immune system’s defense against cancerous cells.

The team also observed an early increase in splenic CD8+ T cells after radiation. The spleen plays a crucial role in the activation and proliferation of these cells, which are vital in fighting blood-borne pathogens and cancerous cells. While the research is still in its early stages, it opens exciting possibilities for improving outcomes in the treatment of triple-negative breast cancer. Monitoring vascular changes to predict therapy responses and shifts in the immune landscape of the tumor may help enhance results for patients with limited treatment options.

“What sets this research apart is its ability to non-invasively track tumor changes that would be generally be detectable via biopsy or imaging methods that may not capture the full response. This ultrasound technique provides a window into a patient’s tumor response to treatment that may help inform clinical decisions more quickly,” said Shannon Martello, the paper’s lead author.

“The findings suggest that ultrafast power doppler ultrasound could become a crucial tool in personalizing cancer treatment. By providing accurate indicators of treatment effectiveness, clinicians may be able to tailor therapies more rapidly and precisely,” added Marjan Rafat, assistant professor of chemical and biomolecular engineering.