they are keeping my meds on 100mlg very low lose and dont want to change it yet
Yes - I meant thyroglobulin. Chalk another one up to brain fog.
In response to the post by Tammyinal, do you mean thyroglobulin level not thyrogen level?
What type of thyroid cancer? Did you have followup radiation (I-131 or RAI)?
The thyrogen level in post-cancer treatment patients should be <.2 and the TSH should be <.1. Those are the levels that help suppress any further cancer growth. Any increase in those levels after being on stable thyroid meds means a recurrence.
PET scans don't pick up thyroid cancers (at least papillary or follicular) well. Those cancers absorb iodine which is why they do RAI (radioactive iodine or I-131) scans. Often those cancers (especially papillary) spread through microcancers which would be too small to visualize on a PET scan. PET scans also use a radiated version of glucose which most active cancers will absorb but, like I said, radioactive iodine is a much better indicator on thyroid cancers.
Talk to your doctor about an I-131 scan. Are you being treated by an oncologist or endocrinologist?