Dramze

Back to your situation:
Here is a tip that everybody agrees with (at least so far):
next blood test, ask your doctor to order a TSH or Thyroid hormone test. Understand that you are asking the doctor to do nothing more than check two more boxes on blood test form:
866X (T4 Free) and 899X (TSH). It's extremely important to get the actual TSH number that you have now before Radiation.
Again, my tip is from my personal experience, not a clinical trial but IMO just as valid
While my CCC doctors were top notch on Cancer, for related issues like Thyroid - "not so much". I was not only extremely tired but also froze for two years, even in summer, and kept a winter coat on in air conditioned places yet I was constantly told: "Your TSH levels are normal" and I did not ask for the actual numbers or test results. Turns out however there is controversy over what is the right TSH level with labs having a 5.5 or a 4.5 as okay even though endocrinologists who went to Medical school the 21st Century conbsider 3.0 as the highest acceptable level. Before TX, I had a TSH of 1.6 and after TX it shot up to 4.3. Now that I am "on the pill" (levoxyl), I am finally warm again. Plus my energy is back.
Even better if post radiation, your blood test shows you have the same or very close TSH level. But without a pre radiation test, then it's just wild guesses on even the best doctors' part.
Charm