Inhwan (Jason) Yeo, Ph.D.

Think your job is difficult? Inhwan (Jason) Yeo, Ph.D., is a medical physicist at Wilmot, and among his many challenges is making sure that radiation beams are directed precisely at tumors when a patient is getting treatment. His job gets even harder when those tumors move like they do in the lungs, where they shift with every breath.

“My role is challenging, but it is also rewarding,” Yeo says. “I use technology that changes continuously, and I have the precious opportunity to use my knowledge and skills to help people when they are sick.”

While most people who need radiation therapy at Wilmot Cancer Institute may never meet Yeo, he plays an important role in their care. He leads the team of medical physicists who work behind the scenes at all of Wilmot’s Radiation Oncology sites to make sure that each patient’s radiation therapy is delivered as precisely as possible.

Medical physicists work closely with the radiation oncologists, the doctors who determine what area of the body to treat and how much radiation to deliver.

“Radiation oncologists are in charge of the clinical aspects of treatment, and we are in charge of the technical integrity of treatment,” Yeo explains.

Medical physicists make sure the equipment used in radiation treatments, such as the linear accelerators that deliver radiation, is working properly. They also have an important role in treatment simulation.

Before treatments begin, the radiation oncologist works with dosimetrists and the medical physicist to determine a treatment plan, through computer simulation, to make sure that the radiation can be delivered precisely to the target and with the least exposure to healthy tissue. During this process, Yeo and his team help to develop the treatment plan that will be most effective. They help determine the most precise angles for delivering the radiation beams and their associated radiation doses.

Medical physicists are also involved in delivering brachytherapy, an internal treatment using radioactive seeds that are surgically implanted on tumors. They use computers to plan the treatment and help determine where to place the seeds on the tumor.

“We are technically ensuring that the prescribed radiation is accurately and precisely delivered to the disease site while saving healthy tissues from exposure,” Yeo says.

As technology and treatment techniques change, medical physicists must adapt quickly. They are also looking for ways to improve treatment through research. Yeo, for example, is working on methods to ensure that a consistent dose of radiation is getting to tumors that move, addressing the issue of areas that may get too much or too little radiation.

 For Yeo and his team, these challenges are worth it.

“Radiation that passes through a patient is like a surgical knife, and we make sure that it is delivered accurately,” Yeo says. “Our work as medical physicists affects the treatment of patients every day, and through our efforts, we are raising the standard of care for patients today and in the future.”