[Mtngrl]

I get a combined PET/CT. The PET shows areas that are "glucose avid." The CT gives a picture of the shape and size of the thing, but, as Tiffany says, can't detect whether it's metabolically active or not. But if you've got a known cancerous tumor and it's smaller (or gone) on the CT scan you know you have a therapeutic response.

The PET detects inflammation. Cancer is an inflammatory process, and since they know I have cancer it's pretty safe to assume that areas of increased FDG uptake on a PET scan are cancerous. But other things also cause inflammation. I've had pneumonia, bronchitis, and radiation pneumonitis recently. All those areas would be FDG avid too, as would sore muscles from doing strenuous exercise.

I was taught that it's not accurate to make comparisons of readings between scans. You might be on a different machine. Your base metabolic level might be different on the two dates.

The data you get from any kind of scan need to be interpreted in an educated manner, in context and in light of other data. It's part art and part science.

Amy