TSH is 4 three months post RAI for Pap Thyca

[shannon828]

I just had my bloodwork done for my three month post RAI treatment (75 mci) for Stage 1 Papillary Cancer, and while my Tg was suppressed (.096), my TSH is at 4.  Bloodwork done before my treatment (pre-RAI. but post surgical removal of my Thyroid gland) showed my TSH suppressed at under 1.  What is the reason for the elevation in my TSH?  I have been feeling pretty great, but have noticed some tiredness here and there (just thought it was normal fluctuations of energy levels).  My doctor has increased my dose from 125 to 150 of Synthroid.  I am 5'4" and 115 lbs.  Do you think going to 150 is enough of an increase in my dosage to get my levels suppressed again?

[shannon828]

I guess my question was really why would my TSH be elevated?  Is it just a matter of getting my dosage right to sufficiently suppress it or should I be concerned about recurrence?

[Mark Lupo, M.D.]

Check the TSH vs Tg values - I think you may be interchanging them as most labs would not be able to give a .096 Tg level.  Increasing the levothyroxine dose usually decreases TSH and Tg both.  It has only been 3 months since RAI, so may take more time for Tg levels to be undectable.