A groundbreaking study introduces a new method using magnetic resonance imaging to track the body’s immune response during cancer treatment, which could change the way we understand tumor development and treatment success. This research, led by Dr. Fanny Chapelin, Harrison Yang and Brock Howerton from the University of Kentucky and the University of California San Diego, shows how magnetic resonance imaging can be used to observe macrophages—immune cells that are crucial in how tumors respond to Radiation therapy. The study, published in the journal Cancer, provides new insights into more effective cancer treatments by providing real-time images of tumor changes during treatment.
“Radiation therapy has long been used to treat cancer, but tracking the body’s immune response during the process has been challenging,” explains Dr. Chapelin. “Our study demonstrates how magnetic resonance imaging can monitor macrophage activity within tumors without the need for invasive procedures, allowing us to gain a clearer understanding of the tumor environment.”
The researchers used a special fluorine-based compound injected into mice with breast or colon cancer to label macrophages so they could be seen on MRI scans. “This allows us to track the movement and behavior of these immune cells immediately after radiation therapy,” Yang shared. The study found that macrophages, which are normally involved in fighting infections, were attracted to the tumors after treatment. However, immune cells respond differently in breast and colon cancer.
Fluorine-based MR imaging offers significant advantages. This method provides a clean, quantifiable signal, unlike traditional MRI, which often uses more complex reagents to make objects visible. This method allows scientists to observe the behavior of macrophages as the immune system responds to treatment.
In the case of colon cancer, tumors treated with radiation showed a significant increase in macrophages, which halted tumor growth in a little over a week. Meanwhile, the untreated tumors continued to grow dramatically. “We noticed a significant increase in the fluoride signal, which indicates that more macrophages are entering the treated tumors,” Dr. Chapelin said. This increase in immune activity appeared to be directly correlated with tumor shrinkage, showing how important the immune system is in fighting cancer after radiation.
In contrast, breast cancer models showed a slower immune cell response, but tumors still shrank significantly after radiation therapy. “Although breast tumors did not stop growing like colon tumors, we did observe a modest increase in macrophage activity and a steady decrease in tumor size over time,” Howerton noted.
These results are particularly important because they suggest that the activity of macrophages on magnetic resonance imaging can be used as a marker of treatment effectiveness. This can help doctors assess the progress of radiation therapy without requiring a biopsy, which can be invasive and uncomfortable for the patient. Dr. Chapelin added: “This approach provides a real-time, non-invasive way to observe the body’s response to cancer treatment, which is an important step toward providing more personalized care to patients.”
This approach has potential applications beyond tracking macrophages. By giving doctors a clearer picture of a tumor’s internal environment, it can help predict whether the cancer is likely to come back, a common problem after treatment. Macrophages within tumors can help fight cancer or, in some cases, promote its growth. Therefore, being able to monitor these immune cells in real time could provide doctors with valuable clues about the likelihood of cancer recurrence.
The research team also noted that this technology could be used in other cancer treatments, including enhancing the immune system’s ability to fight disease. “By understanding how immune cells such as macrophages respond to different therapies, we can ultimately tailor treatments to each patient to make them more effective,” Dr. Chapelin explained.
This breakthrough has the potential to revolutionize cancer treatment by providing a non-invasive way to monitor immune responses, thereby avoiding the need for frequent and uncomfortable surgeries such as biopsies. The researchers plan to continue exploring how this technology can be used in different types of cancer and aim to incorporate it into clinical practice. “Our goal is to move this technology from the laboratory to the clinic, where it can provide physicians with immediate feedback and help improve patient outcomes,” Dr. Chapelin said.
In summary, the use of magnetic resonance imaging to track macrophages during cancer treatment offers a promising new approach to improving the effectiveness of radiotherapy. By providing a non-invasive way to monitor what’s going on inside tumors, the technology can help doctors better understand how tumors respond to treatment, predict whether cancer is likely to return, and tailor treatments to provide patients with the best care result.
Journal reference
Yang, H., Howerton, B., Brown, L., Izumi, T., Cheek, D., Brandon, JA, Marti, F., Gedaly, R., Adatorwovor, R., and Chapelin, F. “Giant Magnetic resonance imaging of phagocyte response to radiotherapy. Cancer, 2023, 15, 5874.
About the author
fannie chapelin is an assistant professor in the Department of Bioengineering and Radiology at the University of California, San Diego. Fanny received her Ph.D. In 2019, she received her PhD in bioengineering from the University of California, San Diego. She has been developing non-invasive imaging techniques to visualize cell therapy and inflammation in cancer and other immune diseases. The impact of her research has been recognized in numerous publications, including the French Scientific Engineer of the Year Award, and the NIH KL2 Award. She is a Fellow of the International Society for Magnetic Resonance in Medicine, a Scialog Fellow and a former UK Research Scholar. Her research aims to provide scientists and clinicians with methods to visualize cell distribution, fate, and efficacy to improve clinical practice and patient care.
Harrison Young is a senior at the University of Kentucky studying biomedical engineering on a Singletary Scholarship. During his undergraduate career, he conducted research in the Cancer Imaging and Immunology Laboratory. The Commonwealth Undergraduate Research Experience and the Markey STRONG Scholars Program funded his research. His work has been recognized at the university level with the Biomedical Engineering Sophomore Trailblazer Award and nationally with the Barry M. Goldwater Scholarship. He plans to continue studying cancer immunology after completing his bachelor’s degree.
Brock Howerton I am a second-year doctoral student. Graduate student in the Department of Bioengineering at the University of California, San Diego. He received his master’s degree in chemistry from the University of Kentucky, where he developed a strong interest in organic/polymer chemistry and drug delivery. Currently, Brock is focused on developing novel immunoimaging contrast agents for cancer detection and T-cell tracking No. 19F/1Magnetic resonance imaging. He is an active member of the International Society for Medical Magnetic Resonance Imaging and the Bioengineering Graduate Student Society at UC San Diego. His work focuses on creating functional synthetic platforms that provide clinically translatable imaging tools. Block’s research aims to bridge the gap between laboratory discoveries and real-world medical applications, providing clinicians with innovative tools to improve the diagnosis and treatment of disease.
