Colleen,
I have been on thyroid for about a year. I was told about taking it on an empty stomach and waiting one hour to eat. I was also told not to take calcium for atleat 1-2 hours after taking the synthroid.

Cacky

My dad was on synthroid for many years. I remember that they had to "dial in" the correct dose and slight changes can make a big difference. The NCCN guidelines recommend TSH level blood tests every 6 months and, as Eileen stated, they should have done a baseline test prior to starting Tx. Patients receiving XRT are a high risk of thyroid failure because of collateral radiation damage. With IMRT, they can program the beamlets to avoid the thyroid, so thyroid problems are less common for patients recieving IMRT. The location of the tumor in relation to the thyroid would also play a role. It took several years for my thyroid function to return to the low end of normal and it has pretty much stayed there since then.