Wednesday, November 17, 2004

thyroid & thyroid cancer, 101

It was brought to my attention today that I use a lot of terms and abbreviations that are not familiar to anyone who hasn't had thyroid problems, or thyroid cancer.

So I thought I would put together an entry of the most common terms and abbreviations I use.

First, the thyroid is a little gland shaped like a butterfly on the front of your neck. It produces a bunch of different kinds of hormones, but all of them are related, and all of them are used by our bodies to regulate our systems: T4 is made most abundantly, then to a much smaller degree, T3, and then T2 and T1 and some other stuff, too. T4 can be converted in our bodies into all the other thyroid hormones, so a lot of doctors think you only need to take T4.

People who have hypothyroidism, like me, have thyroids that don't make enough T4, etc.

We supplement this with synthetic T4. The two most popular brands are Synthroid and Levoxyl. There are literally millions of people in the US on these drugs, because hypothyroidism is quite common.

I also supplement with T3, with the brand name Cytomel. It works for me.

Many times I'll refer to "hypoT" or "being hypo", which is just shorthand for saying "hypothyroid", which is way too long to type all the time.

Being "hypo" can bring with it a whole bunch of symptoms. Probably the most common, which I do not have, is intractable weight gain. Then again, I am pretty stringent in my diet and try to keep my carbs controlled. Again, that's what works for me.

My thyroid problems stem from Hashimoto's Thyroiditis, which is an autoimmune disease. My body started attacking my thyroid... maybe because of the cancer? Which came first, the Hashi's, or the cancer? It's hard to tell. Hashi's is just short for Hashimoto's Thyroiditis, as I'm sure you've figured out by now. It causes hypothyroidism.

Before my surgery, my only thyroid diagnosis (sometimes I will abbreviate that as dx) was thyroid nodule on the right lobe, consistent with Hashimoto's.

A nodule is just an unusual mass, like a cyst or a tumor. Nodules can be benign or malignant. Up until my surgery, there was no concrete indication that my nodule was malignant. Indeed, my surgery showed that I had malignancy -- cancer -- outside of the nodule, too.

I had significant metastases, that is, the cancer had spread to my lymph nodes and underlying soft tissue around the thyroid. My surgeon worked a long time getting out as much as he could.

The tests I had done before my surgery were ultrasound which I often call u/s. This is painless; the technician smears some gel on the throat and they use sound waves to look at the soft tissues in the neck. They can measure how big the thyroid is, and see if it has any unusual characteristics. It is an excellent diagnostic tool as far as it goes, but it can't be used to diagnose cancer.

My u/s showed a lot of calcifications in the nodule and other structural changes in the thyroid itself which were worrisome to my endo, the doctor who treats my thyroid condition, short for endocrinologist. Endos are specialists not just in thyroid issues, but in the entire endocrine system. It's huge and complex. EndocrineWeb is a great site that can give you a ton of information about the Endocrine System.

The other test I had was an FNA or fine needle aspiration biopsy. This test involves obtaining cell samples from the nodule using a thin needle. The endo sticks the needle into the nodule (using u/s guidance in my case -- she looked with the u/s to be sure it was going where she wanted to collect the sample from). FNAs hurt but not unbearably so.

The biggest problem with FNAs is that they collect very tiny samples, and unless you get lucky, the FNA may miss the real story, as it did with me. There was a "rare pseudonuclear inclusion" on my FNA pathology report, which was supsicious but didn't warrant even a mention of cancer. However, this, combined with the changes my endo observed on the thyroid u/s was enough for her to recommend the thyroidectomy, or surgical removal of the thyroid.

After my surgery, a few new abbreviations come into play:
LID, or Low Iodine Diet
This is a pretty restrictive set of dietary guidelines designed to maximize the effectiveness of RAI (see below). No dairy, nothing from the sea, no iodized salt, and nothing commercially prepared with salt, since there's no way to tell whether they used iodized salt or not... it has been an interesting experience. Particularly the no dairy aspect!

NucMed = Nuclear Medicine, my Dr L. He is the one who administered my dose of RAI (see below) to ablate, or kill off, any remaining thyroid or thyroid cancer cells still around my body.

RAI = Radioactive Iodine
This is the "magic bullet". Since the type of cancer I have is well-differentiated, which means it's cancer of thyroid cells, it can be treated by taking advantage of a unique property of thyroid cells: they are the only cells in the body that will absorb, or uptake, Iodine. If we give them Iodine that is radioactive, the particles emitted from the RAI will disrupt the thyroid cancer cells and kill them.

Of course, the radiation from the RAI that is still circulating in my body is being emitted constantly, and it is collecting in my salivary glands, as well as in liver, kidneys, and bladder -- that's why it's so important to flush out those areas constantly after the dose is administered, to reduce any potential side effects to those organs. I'm swilling lots of water to keep everything moving and wash out the RAI.

It's easy to wash the RAI out of those other systems, but it will stay inside the thyroid cancer cells, and in any hapless remaining normal thyroid cells as well. Hopefully, they'll die off.

The doctors will get a good look for any other metastases when I go for my WBS, or whole body scan. The scan will show where there was uptake, where Iodine was absorbed by thyroid/thyroid cancer cells.

After the scan, we'll have some idea of where we stand with metastases and remaining thyroid/thyroid cancer tissue. Then I will be monitored via blood tests to see what's happening. The main two things that will be looked at are:
Tg, or thyroglobulin, which is a substance produced by thyroid and thyroid cancer cells. Basically, I shouldn't have any. If I have a certain level, or if the level starts to increase, that can indicate a recurrence of the cancer.

TSH or Thyroid stimulating hormone, is produced by the pituitary gland to request the production of thyroid hormones. I will take a dose of T4/T3 (most likely) to suppress the pituitary from ever making any TSH at all -- since we don't need anything around that could stimulate any remaining thyroid cancer.

A few other common abbreviations around here:
DH, DD, DS1, DS2: Dear Husband, Dear Daughter, Dear Son the first, Dear Son the second... even though I use my own name here, I have "a thing" about not using my husband's name, or my kid's names, or anyone else's name in my personal life, actually. You may be reading this and thinking, "I know who she's talking about," and that's fine. I just don't feel I have the right to be putting anyone's business but my own out here, and if I don't name any names, well, then, it's not gossip. OTOH, this is a space for me to work out the insanity in my life, so there will be times when I talk about things that other people do that make me crazy. I just don't talk about them by name.
LC = low carb, my way of eating for about 6 years now
MILC = Make It Low Carb, my monthly column published at LCL,LowCarbLuxury.

Hope this helps! I will update this if anything else occurs to me.

1 Comments:

ChaiTime said...

This has been a very educational post! I, for one, appreciate the definitions. You are very good a putting it in understandble lay terms. Although I'm sure this has got to be a pain, you sound good. I'm very glad that you were able to be online during your isolation. It helps to know how you are doing.

A big, virtual, non-radioactive hug!

12:12 PM  

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