Magnetic resonance imaging of macrophage response to radiation therapy

Motivation: Cellular response to cancer treatment is difficult to track in real time. Standard practice involves immunostaining of a biopsied tumor, but this is severely limited by a number of factors. Goal(s): Non-invasive imaging methods such as MRI could obviate the need for biopsies and serve as a biomarker of radiation therapy efficacy. Approach: This study aimed to observe macrophage response in a mouse model by use of a fluorine nanoemulsion and 19F MRI. Results: It was shown that macrophage recruitment can be quantified through MRI. Moreover, the findings suggest that macrophage response to radiation therapy is dependent on several factors including tumor origin. Impact: Our results demonstrate the potential of 19F MRI to non-invasively track macrophages during radiation therapy and its prognostic value with regards to tumor growth. This technique will be extremely beneficial in future analysis of inflammation’s role in tumor recurrence.