In the Spotlight

What first attracted you to Madison and Medical Physics?

I came to UW-Madison in the late 80s from Pennsylvania with a background in Nuclear Engineering. I switched fields around the year 2000 to work with Rock Mackie, the inventor of Tomotherapy, and was his right-hand man here for about 10 years. When he retired, I took over some of his classes and research. I’ve transitioned recently from pure physics and radiation therapy into more biophysics.

What is your current research?

I’ve actually made a big discovery with my student, Leonard Che Fru, who will have an article coming out soon. For decades, we’ve noticed that there are a lot of changes in tumors with respect to oxygen and hypoxium (cells experiencing a lack of oxygen). We are looking at slow dynamics, which must be from vascular changes or metabolism changes. We’ve explored those fluctuations since they seemed like very coherent oscillations, and we think we have a mechanism for it. We think it’s the glycolytic oscillator, which is the same mechanism that pulses your insulin. It’s caused by a depletion of glucose coming into the glycolysis chain. But, there’s also random blood flow, which makes the oscillations irregular. It’s a good example of how physicists and biologists can make huge discoveries working together.

What effect will this have on the field of Medical Physics?

Medical Physics is changing to be more coupled with biology. We are moving towards the personalization of radiation therapy in patients; doctors should be able to adapt the treatment per patient, so they can immediately see how the treatment is going to improve it right away. To do this, it’s not just about the location of the tumor in the body, it’s about how is this particular tumor is responding to this particular radiation treatment. We’re also moving to hypofractioning treaments, where patients receive radiation less times over the course of their treatment, but at higher doses. The dose is higher, and you have a more limited opportunity to change it, so it’s more difficult. I have another student working with Keven Eliceiri in his microscopy lab, and they’re noticing that a patient’s metabolism gets kicked within 10 minutes of a radiation dose. My hope is that these oscillations are different from one patient to another, and the doctors can use this to personalize the treatment.

What is your favorite part of your job?

Research, Teaching, and Service, in that order. I love teaching people how to dig into a science problem and come up with something. Much of the research is also teaching, just more one-on-one. The classroom is turning out to be much more enjoyable than I thought it was going to be, and I’m actually hoping to make a book out of my notes. We’re trying to modernize the curriculum, and I’m involved with several campus-wide initiatives that gets me involved with people from other departments.

What is the best piece of advice that you’ve received?

Winston Churchill said when London was being bombed: Never Give Up.

For example, we were using optical technology, which was new to me. We saw lots of changes in the data we were getting, since we weren’t sampling at a high enough rate. We didn’t know if the results were real or if it was our equipment. We went to an MRI device and a photoacoustic device, we called in specialists, and finally determined that our results were real. It took years, but we accomplished it. If you think you’ve got a new idea, keep pursuing it. If it gets clearer and clearer, you still have a long journey convincing everyone else. This new article has taken four years to develop, and we aren’t done yet.

What is your favorite part about being a teacher and mentor to students?

I love the interesting, intellectual conversations. After class, sometimes a couple of students are stuck on a concept and want to know more. They’ll come to my office and we’ll dig into it together, and I find that I also learn something out of the process. Even things that I thought I knew like the back of my hand, there’s nuances that took teaching to bring out.

If you had a million dollar grant, what would you do?

I would pursue these oscillations and fast changes in metabolism to radiation right away. I think we could make very big strides – I just need the money to get some equipment and a team of students. The end result goes beyond radiation therapy. It’s a new observation about what makes tumors aggressive. When metabolism goes through swings like this, there’s a molecule that could lead to calming tumors down so they can be treated more effectively.

If you could pick an entirely new career, what would you do?

That is really hard to say. I feel like my ability to look at these tumor oscillations like nobody else has comes from being in theoretical plasma physics for the first part of my career. Plasmas have a lot of nonlinear oscillation activities, and I learned how to analyze that in a whole different realm. It was the same techniques I applied to this study, and the students took it and ran with it. I don’t know if I would change things at all. I enjoy at this midpoint in my life learning a new type of science in the work I’m doing with biology. I have no biology training besides High School, and there are so many variables that it’s very unlike a physics problem where you build from the ground up with a few key equations. We never did hypothesis testing in physics, since we’re using equations that work 100% of the time. Now, there’s so much going on inside of a single cell that there are so many pathways to choose. If I learn this new way and match it with my old, I think I’ll be really powerful.