Had tyroid cancer twice is it possible to get it back again?

It's possible: Thyroid cancer may recur or spread. It's important to get regular checkups to follow up on your treatment. If you notice any new lumps or enlargement of nodes in your neck, see your doctor immediately.

Thyroid cancer: Did the same cancer come back, or did you have two different kinds of thyroid cancer? The latter is unusual. The combination of surgery, radioactive iodine, careful monitoring and repeat RAI if necessary can usually eradicate thyroid cancer. If the initial treatment were incomplete (eg. surgery alone; inadequate dose of RAI) then it certainly can come back.