19F MRI To Monitor Cancer Progression Post-immunotherapy and Radiation Therapy

Motivation: Imaging is often combined with biopsies to diagnose and monitor cancer progression, but biopsies can be invasive and time-consuming. Goal(s): A promising alternative is 19F nanoemulsion as a contrast agent for MRI, which labels systemic macrophages, enabling noninvasive tracking of macrophages and tumor growth after treatment. Approach: This study used a fluorine nanoemulsion and 19F MRI to observe macrophage dynamics in murine cancer models post-radiation therapy or immunotherapy. Results: Our radiation therapy study showed significantly higher fluorine signals and reduced tumor growth in treated mice. Our immunotherapy study achieved a 75% response rate, distinguishing responders from non-responders through tumor size obtained via MRI. Impact: 19F MRI enables noninvasive monitoring of macrophage dynamics during radiation therapy and immunotherapy treatments, as well as anticipate tumor growth. This approach will be invaluable for future research on the role of inflammation in tumor response to therapy and recurrence.