does radioactive iodine affect pregnancy?

[maliyu]

hi, i just had a thyroidectomy 2 weeks ago and the pathology report came back saying that there are microscopic cancers in my lymph nodes. next week i'm supposed to discuss my options. my doctor mentions my prognosis is good and positive, based on my age and the size of the cancer in thyroid being small, she says i'm at stage 1.  now, i'm just worried if i do radioactive iodine therapy, there will be side effects such as damage to the ovaries.  i'm still of child-bearing age and never had children before. i'm just confused because my family doctor and another endocrinologist both said i can still have a family and not to worry, while my endocrinologist mentions there might be a risk. i'm just wondering if anyone had any problems getting pregnant after radioactive iodine therapy.  she says microscopic cancer is harmless and i shouldn't be worried about it right now and that there's a 1% chance it might come back.  maybe it won't come back at all and will it be safe to wait  years later to do radioactive iodine therapy after i have kids?  i'm confused, any advice appreciated!

[maliyu]

Thanks for responding Dr. Lupo. I don't have a copy of the pathology report right now so I don't know all the details. I'll make sure I'll ask those questions you've suggested.

What I can tell you now is that I had a 7mm nodule, did a FNA and was diagnosed with papillary cancer. so, I had a total thyroidectomy and now my doctor said that the pathology report indicated no signs of cancer spreading to the other lobe, but found microscopic cancer in the lymph nodes.  she didn't mention any other tumors. Is it necessary to treat microscopic cancer at all? what would happen if i don't? will it be foolish of me to postpone the I-131 until it becomes larger than microscopic?

[Mark Lupo, M.D.]

If the lymph nodes showed evidence of cancer involvement, there may be benefit from I-131 treatment.  It really depends on careful review of the pathology report -- ie was there extension beyond the thyroid? How many lymph nodes?  How may tumors in the thyroid? What was the size?  Was there an aggressive subtype? Was there vascular invasion?  These are the questions we ask when deciding if one needs I-131.  It is not urgent to get I-131 in most of these Stage I cases (but remember, Stage I may be due to age alone and not a low risk for recurrence - so ask your doctor to clarify this).

I-131 should not alter your ability to conceive and have a successful pregnancy.  Would need to wait at least 6 months after I-131 to start trying for pregnancy.

Now - if this was all microscopic classic papillary cancer confined to the thyroid w/o lymph node involvement -- then NO I-131 is necessary.