How Molecular Imaging and Nuclear Radiology Arm Scientists to Fight Cancer

Immunotherapy research propels scientific progress and helps patients live longer, healthier lives using the human immune system to cleanse the body of cancer. Like with any scientific discipline, immunotherapy contains many different investigative areas of interest for scientists looking to drive future progress. Some scientists, like Mark Sellmyer, MD, PhD, assistant professor of radiology at the University of Pennsylvania and a new CRI Lloyd J. Old STAR, seek to enhance clinical cancer care by taking a unique interdisciplinary approach to their research. 

“It is accelerating to have foundational support from CRI. We are expanding our operations and frankly taking risks that are part of the goals of the STARs program.” 

Mark Sellmyer, MD, PhD, 2024 CRI Lloyd J. Old STAR

Specifically, Dr. Sellmyer’s multipronged approach to immunotherapy fuses two areas of research — utilizing positron emission tomography (PET) scans to locate immune cells in cancer and nuclear radiology. His novel approach involves rigorous research that combines methods which have been historically used to detect cancer and conduct radiotherapy:

1. Molecular imaging – a medical and biological research field focused on the production and practice of approaches to visualize, define, and quantify biological processes. This occurs on several levels: within molecules, cells, and tissue. The difference between molecular imaging and traditional scans is that the former grants real-time insight into the function and actions of specific molecules.

2. Nuclear radiology – a clinical field that harnesses radioactive molecules that emit signals which can be recorded. Some of these molecules, or radiotracers, such as radiolabeled glucose and radioactive iodine, have been critical assets in cancer care for years. 

His multi-discipline research practice is unique in immunotherapy and involves developing PET radiotracers that track the location and quantity of immune cells while also deciphering immune cell dynamics in tumors. Dr. Sellmyer’s lab is heavily invested in creating molecular tools that can highlight live immune cells as they function.

“Our approach creates a reporter gene that tells us where the cells are,” he explained. “This is similar to how green fluorescent protein can be used to track cells or proteins using a microscope and how luciferase from the firefly can be used to track cells in small animals like mice.” 

Making the leap from basic or animal-centric biochemical tools to ones that could have human applications for cancer immunotherapy has led Dr. Sellmyer to collaborate with scientists at the University of Pennsylvania in various research fields. This includes researchers in labs that focus on cancer biology, immunology, cellular immunotherapies, and RNA innovations. This organized web of science demonstrates how a multi-layered approach can serve ambitious goals in immuno-oncology. His research areas inform precision medicine, which tailors healthcare strategies based on an individual’s specific treatment needs. 

“Molecular imaging now provides you and your clinician detailed information about the type of tumor you have and your clinical stage, which guides the choice of therapy,” Dr. Sellmyer said. “The future is very bright for the integration of imaging and chemical biology tools in the journey of a patient through clinical cancer care.”