Re: Can thermography identify cancer cells from normal cells?

Dear Michael, You've asked a complex question! I think the answer to your question is probably no, for the following reasons.

Yes, it's true, cancer cells do grow faster than normal cells, and this may generate more heat, but it can't be a lot more heat. Human cells are happiest at 98.6F (body temperature), and begin to become very unhappy at higher temperatures. For instance, if you get heat stroke, and your body temperature goes up to 106F, you fry your brain and organs and die. So basically cells cannot tolerate a big deviation from 98F for too long.

Let's assume that your cancer cell/tumor is a whole degree warmer than surrounding tissue. Most of that excess heat is going to be dissipated by the blood that supplies the tumor, so you're not going to see that big a difference in temperature. And even small tumors have to have a good blood supply. Furthermore, the machine would have to be able to distinguish rapidly metabolizing tissue (say skeletal muscle or heart or regrowing bone if you've recently broken a bone) from the tumor. It might be easy to mistake a tumor for normal regions of rapid growth or vice versa.

A final thing to consider is the depth within the body. If you model the body as a cylinder with a radius of 9 inches for a relatively fit person, your IR detector would have to be able to measure temperature fluctuations at that depth too. That might be tough to do.

There are groups out there who are researaching non-conventional tumor imaging strategies. The National Cancer Institute even funds them. If you want to look more at what sorts of research is being funded, the following website tells you about it.
http://otir.cancer.go v/tech/uip_awards.html
Your thoughts on this topic are very clever! Keep up the good work!

Finally I have to acknowledge my friends from college for their help in answering this question. We are a bunch of science and engineering nerds, and they helped me out with the engineering aspects of your question.

Please feel free to contact me at tegen@alum.mit.edu if you have any further questions!
Cheers, Sarah