I had a mri prior to my surgery that i think told them where and how large the tumor was. I am scheduled for a cat scan with the rad on'gist this friday to map out where he will be rad me. No one has mentioned a pet scan to me. What is the difference between the three different types of scans? I am confused as to the difference between these three different scans. Is one better than another in exposing any remaining cancer? Thanks for your help in advance. Dan

Daniel,
Brian and others know a lot more than I about this subject but I can shed a little bit of light for you. CT scans seem to be the standard follow up for oral cancer. PET scans reflect glucose or sugar buildups in various parts of the body which may show a tumor's presence because they consume inordinate amounts of sucrose.
PET scans are expensive, and therefore not preferred by insurance companies and , to my understanding, can often result in false positives that might cause you anxiety or to undergo invasive procedures to make sure that the tumors are not present.
I know that there are some archived threads here on the subject because I once asked the same question myself.

Danny G.

Daniel, the hospital I deal with uses a combination PET/CT, does both scans at the same time, and the end result is a kind of rotatable 3D image on the computer screen, or printed image on paper.

I think the idea is that they compliment each other, the CT shows the mass, and the PET highlights weather it's cancerous or not.

Problem is, the PET works on glucose uptake, so maybe a sore muscle that's healing could show up as positive, as well as infectous lymph nodes. I dont' think any imaging product can tell for sure if there is cancer, just that there is something unusual going on. The only "for sure" is biopsy, either fine needle or other.

The one other advantage of the PET/CT approach is that if the hospital has the whole system, including the IMRT radiation accelerator, then it all links together by computer for more accurate radiaton treatment.

I'm just coming from the "user" standpoint, others have more supplier side information so might be more helpful.
Bob S.