Thyroid cancer

A place for people affected by thyroid cancer to support one another, ask questions, and share their experiences.

Thyroglobulin levels 3 weeks after RAI too high? Too soon?

Posted by

Hey guys, thank you for being here. I had my thyroid removed and 82 lymph nodes, 3 months later I had RAI, following up with a follow body scan and a CT, the CT found multiple nodules in my lungs 8mm and smaller that the whole body scan didn't. I just got my blood test results for Thyroglobulin online that I took 3 weeks after RAI and my Thyroglobulin was at 22.5 ng/mL. 

I know I am suppose to be under 2 ng/mL as a good sign of cancer free. The doctor told me it takes RAI 2-3 weeks to kill thyroid tissue, is this a sign it didn't work too well or too early of a blood test and the Thyroglobulin hasn't exited my blood yet?

Thank you guys!

Posted by

Hey there

Welcome to the forum, though I'm sorry you need to be here.

Ok, so, this is a bit of a complicated one.

First off, are you saying you got your results off an online system, or are you saying that you took an online blood test and got the results back? I'm hoping it's the first! lol

RAI works on the body for 6 months, so I'm not sure what your doctor was talking about with the 2 - 3 weeks. Wherever it has been absorbed, it wil be working away for 6 months, killing things off which is why if someone needs a second dose then they generally have to wait 6 months after the first before getting the second. Did your WBS show uptake in your neck, or anywhere else?

So over the next 6 months, your TG level should decrease as the RAI works wherever it was taken up, and kills off what it was absorbed into.

Now comes the complicated bit. These things in your lungs didn't show up on the WBS, which means the RAI wasn't taken up by them. This could mean a few things: They aren't thyroid cancer and are something else, they are thyroid cancer but weren't 'active' so didn't absorb the RAI, they are thyroid cancer and they are iodine resistant. So your doctors are going to have to have chats amongst themselves to try and work out how to move forwards and work out what these things are, or if they are just going to leave them be if they are all 8mm and smaller, watching them to see what happens.

So for now, it's too early to guess if the 22.5 result means those lumps in your lungs are thyroid cancer, but another blood test in a few months time will help them with their educated guessing, as they see how that result has changed.

Sorry I couldn't give you anything definitive or 'good', but I hoped it's helped a bit?

Anything else, please do feel free to shout!



Hope is important because it can make the present moment less difficult to bear. If we believe that tomorrow will be better, we can bear a hardship today. - Thich Nhat Hanh

Posted by

Hey @Lass,

Thank you for always being here for everyone, bless you and I hope your long journey only gets better. I took a blood test at the hospital 3 weeks after my RAI. I am not sure if the endo did this because she wanted to check if my calcium levels got better or for my thyroid levels. Regardless the endo gave up and said my guess was too complicated and referred me over to another endo. She works in the diabetes section of the hospital so my guess is she specials in diabetes. One thing that @PhoenixRising noticed in my other post was that they said the lung nodules might be too small to be picked up by their equipment. Here is the attached report after WBS 5 days after RAI.

X-Ray Dose: CTDIvol: 8.31 mGy; DLP: 342 mGy*cm
CLINICAL HISTORY: 36-year-old male with history of multifocal metastatic papillary thyroid cancer status post thyroidectomy and radioactive iodine
The uptake in the thyroid bed is 0.1% of the administered dose. Multiple foci of iodine uptake are noted in the neck in the region of the left thyroid bed and anterior to the thyroid cartilage, without definite CT correlate, most likely representing residual thyroid tissue in the thyroid bed and thyroglossal duct.
Additional mild iodine uptake is seen in the region of the thymus, without definite CT correlate, which may represent physiologic thymic uptake.
Multiple bilateral pulmonary nodules are noted, most prominently seen where they measure up to 8 mm (3-253,270), suspicious for pulmonary metastatic disease. No definite uptake is seen associated with the pulmonary nodules, possibly due to the small nodule size below the resolution of SPECT.
The normal excretory pathways of iodine in the body are seen, with physiologic uptake in the salivary glands, naso- and oropharynx, GI tract and urinary bladder.
1. Foci of iodine uptake in the neck, compatible with residual thyroid tissue status post thyroidectomy.
2. Mild iodine uptake in the region of the thymus, nonspecific, but may represent physiologic thymic iodine uptake.
3. Multiple bilateral pulmonary nodules measuring up to 8 mm in the right lower lobe, suspicious for pulmonary metastatic disease. No definite iodine uptake is seen in the region of the pulmonary nodules, as the small nodule size may be below the
resolution threshold of SPECT. Attention on follow up examinations recommended.  
Posted by

Heya Alex,

Yeh, so looking at that report it's mostly backing up what I said. So right now, no idea exactly what the lumps in your lungs are, and will need further investigation.

So bloods in a few months time will help with that, and I wouldn't be surprised if you get another scan in 6 months to see if any have shrunk or vanished, or what they've done. Fingers crossed they're just too small for their glowing to be detected, as that's probably one of the best case scenarios I think.

As I said in another post earlier today, dealing with thyroids and thyroid cancer will certainly teach you patience! lol. Might be a while before they work out what these are, and they'll need time between everything for things to happen and change.

But yeh, December was stupidly busy for me, and then I have been quite unwell. So went MIA from the forum for a bit there. Just trying to catch up now! lol



Hope is important because it can make the present moment less difficult to bear. If we believe that tomorrow will be better, we can bear a hardship today. - Thich Nhat Hanh

Posted by

Thank you Lass for everything