TAM-Sense Offers Painless Imaging of Tumor Inflammation

The National Institutes of Health (NIH) has awarded two new grants totaling $6.7 million to researchers at the University of California San Diego School of Medicine. The grants are intended to be used for the development and clinical testing of technologies that can be used to noninvasively examine and quantify immune cells found in tumors.

These immune cells, known as macrophages, play a major role in solid tumor formation and are involved in the body's normal inflammatory responses. The ability to count macrophages noninvasively may aid medical professionals in determining the most efficacious therapies, as the density of macrophages within a tumor can influence its response to treatment.

The method involves giving macrophages minute amounts of a dye that is detectable through magnetic resonance imaging (MRI). TAM-Sense is the technology that the researchers plan to test on patients who have recurrent head and neck tumors. This new phase I clinical study will be the first patient trial for TAM-Sense. To facilitate whole-body imaging, the team will also modify the technology for use with positron emission tomography (PET).

Visualizing a patient’s inflammatory sites throughout the body will be invaluable for accurate clinical diagnosis and for planning precise therapeutic interventions. Current approaches using biopsies are invasive, and some tumors are inaccessible to biopsy. There is an urgent need for new, whole-body imaging technologies.”

Eric Ahrens Ph.D., Professor, Department of Radiology, School of Medicine, University of California San Diego

The TAM-Sense agent is an injection-based fluid that contains minuscule amounts of fluorocarbon dye that is biologically inert. These drops are released into the bloodstream. Macrophages locate these droplets, swallow them, and gather at the inflammatory sites.

The method enables making use of an MRI scanner that has been specially modified to detect the dye inside the macrophages. The patient’s experience is comparable to that of a typical MRI scan.

Beyond treating cancer, TAM-Sense may find extensive clinical use in treating autoimmune disorders, cardiovascular diseases, and infectious diseases, among other illnesses with significant inflammatory components. Since macrophages are frequently present in anatomically precise locations, imaging techniques that identify these sites will facilitate more accurate pain management.

Apart from testing TAM-Sense, the researchers will integrate it with PET scans to further improve its functionality. While MRI offers high-resolution images over small fields of view, PET is superior for full-body scanning to identify diseases.

The researchers see the PET approach as the next advancement in technology, even though more preclinical testing will be necessary before it is ready for use on patients.

Right now, we’re testing one iteration of the technology in patients but there’s also a bigger story at play in terms of empowering MRI and PET with unprecedented precision, which could have wide-reaching implications for diagnostics as a whole. This is only the first step.”

Eric Ahrens, Ph.D., Professor, Department of Radiology, School of Medicine, University of California San Diego