Biophysics vs Medical Physics

I recently attended the APS March Meeting where I attended the Physics Of Cancer Tutorial and spoke in 1 of the 3 "Physics of Cancer" scientific sessions. I knew that there wasn't much "medical physics" in APS, so I was interested in seeing what research on cancer there was.

I think I finally understand the difference between biophysics and medical physics. Many of the talks in the Physics of Cancer session focused on physical properties of cancer cells. What are their elastic properties? Do metastatic cells show different physical properties (size, squishyness) from non-metastatic cancer cells? How much force can cancer cells exert on eachother? One of the talks argued that metastatic vs non-metastatic cancer cells do have different physical properties even if there aren't clear genetic differences.


These were all biophysics talks. They had very little to do with what goes on in the clinic. They were physicists studying the physics of a biological system. I'm not going to argue that this work shouldn't be done... but it is hard for me to imagine it translating into a clinical difference. If there are physical differences between metastatic and non-metastatic cancer cells, I can't imagine a clinical procedure to measure the elastic modulus of a biopsy to give a patient a prognosis. I can imagine that research could lead to understanding the biological pathways (genes, proteins, epigenetics) that lead to the physical differences. This could then have clinical significance due to the biological understanding.

In medical physics, translation is very important. The research is fundamentally applied: what are better image reconstruction algorithms, what are better ways to predict dose in organs, etc. It may take a long time for some of it to get into the clinic, but the research is clearly on the road to the clinic.

The argument in favor of biophysics is that there can be fundamental breakthroughs. By approaching the whole problem in a completely different way, research may lead to a "eureka" moment. In medical physics, research is usually trying to find a better solution to a (clinical) problem that has already been solved. It may make a difference in someone's life in the near future, but it will not be revolutionary.

So here is the definition I think I can use from now on:
"If this work is successful, would it make a difference to cancer patients in the near (on FDA timescales) future?"

Yes: Medical Physics, Bioengineering

No: Biophysics, Physical Biology