false positives

coach13 Member Posts: 3
edited March 2014 in Thyroid Cancer #1
Has anyone every received a false positive on their I scans. I believe I did 6 years ago. I was diagnosed with papillary cancer had scan which showed mets to lung - had treatment radiation and rescanned showed same mets to lung plus a possible met to abdominal area. Doctor thought it was in my kidney. Went to another doctor and he didn't believe it was a met. 6 months later I was scanned again and all the scans were negative except for that same abdominal area again. Doctor said to drink a lot of water and come back next day - I was scanned again and the spot was entirely gone - Doctor thinks that the Iodine got pooled up somewhere in the intestines.


  • Rustifox
    Rustifox Member Posts: 110
    It is very normal to see false positives with I-131 scans, Coach. There are also many very 'normal' areas of uptake - intestines, esophagus, salivary glands, etc - that can often be mistaken for a positive result.

    I also had to return after taking laxatives - and the area of concern had 'moved on', if you know what I mean. ;- )

    You may find this article interesting about I-131 scans/false positives - even a used kleenex in your pocket can cause a false positive reading on the scan (or drool, etc). This is an excellent document on this exact subject:


    Hope it helps. At the same time, it is always important to be followed up correctly - with stimulated/hypo thyroglobulin levels, ultrasound, and in the meantime, having your TSH maintained in suppression (ie between .10 and .50 TSH) for the rest of our lives. We need to remember that thyroid cancer can be persistant or reoccur at anytime - sometimes 5-10 or even 20 years down the line. Each recurrence is potentially more serious, so dilligence is required. All the best to you.
  • alliesnene
    alliesnene Member Posts: 20
    Hi Coach,
    since you were diagnosed with papillary carcinoma, does your endocrinologist check your throglobulin, since this is the tumor marker for our kind of cancer. Knowing what your tg level is should put your mind at ease ;-)!! My experience was different, having battling papillary, this is my 13th year, I am RAI resistant so no uptake. And since my bro in law is an endocrinologist I am fortunate to have the best care in this field. Best of luck to you!