I would think that normal for us would be the same as anyone else, cancer treatment or no cancer treatment.

I have Graves' disease so my thyroid levels have been monitored for several years and I was treated in 2005 with radioactive iodine. My old endocrinologist was very particular that my thyroid levels stayed right in the middle of the range - not on the high end or the low end, but smack dab in the middle. She also felt that the TSH number was not enough and always ran a T3 and T4 level as well.

Stage IV SCC lt lateral tongue, surgery 5/19/08 (partial gloss/upper neck dissection left side/radial free flap reconstruction) IMRT w/weekly Cisplatin & Erbitux 6/30/08, PEG 1 6/12/08 - out 7/14 (in abdominal wall, not stomach), PEG 2 7/23/08 - out 11/20/08, Tx done 8/18/08
Second SCC tumor, Stage 1, rt mobile tongue, removed 10/18/2016, right neck dissection 12/9/2016
Third SCC tumor, diagnosed, 4/19/2108, rt submandibular mass, HPV-, IMRT w/ weekly Cisplatin, 5/9 - 6/25/2018, PEG 3 5/31/2018