As you can tell, I feel passionate about PETscans not being appropriate for follow up care on tongue cancer. They are indeed great for initial diagnostics before radiation as well as helping plot radiation. My insurance does cover them anyway for both diagnostic and followup. Sure a CT can help compensate for the fatal flaw in PETscans, but all the MRI's I have had also have a CT scan done.
I was so upset about my false positives that the CCC agreed to let me sit down in front of the monitor that radiologists use in evaluating PETscans and the software lights up the various areas in contrasting colors that indicate the uptake rate of the sugar. Since normal tongue cancer after radiation takes in more sugar while healing than a cancer tumor coming back, the images indicate cancer where there is none, and miss the true cancer. I had to admit that the images of my PETscan done when I first went into radiation in O7 (for diagnostic and radiation settings) and the color intensity matched almost exactly the same false images on the healing tissues of my tongue on the right side of the October 08 one.. It's not the radiologists fault that the "indicator for cancer" in a PETscan lights up for healing tongue tissue. It's because the basic assumption of a PETscan (cancer tumor takes in more sugar than normal or healing tissue) does not hold true for tongue tissue after radiation. My understanding is that this anomaly does not apply to other types of oral cancer, only tongue cancer. (Or should I call it "throat cancer" like the NCI website).
In fairness to NCI, I have not seen anything on their website indicating that tongue cancer patients should have PETscans for followups. I'm not surprised the guidelines don't support PETscans for follow up in light of my experience.

I agree with Gary that the scans have not given me peace of mind, and in fact only needless worry. I'm grateful my tumor board told me to just disregard the results (and the subsequent surgery did show zero cancer where the PETscan had lit up).

If it makes people feel better to have them, that's their choice. But IMO nobody should worry if they don't get one if they have had tongue cancer and radiation.
Charm