Thyroid Imaging: What is the “Gold Standard” for Thyroid Nodules?

[David Goldenberg MD]
Well, the imaging modality of choice for anything thyroid, whether it's in the thyroid or in the neck is the ultrasound, the good old-fashioned, inexpensive, non-radiating ultrasound. And it's an interesting point. If they come in with their MRI, that's wonderful. I don't really like it when they were sent specifically for an MRI for a five-millimeter nodule, but it happens sometimes again, you know, when patients are referred into our practice specifically for this, oftentimes they come in with all kinds of imaging, but ultrasound is the tried, true, tested imaging modality.

[Ashley Agan MD]
Do you do any ultrasound, in your clinic or are most of your ultrasounds done in your radiology department?

[David Goldenberg MD]
I am fully credentialed to do ultrasounds and I'll do them every now and again myself, if I think it will add something. A lot of times the patients are sent to radiology, just because of timing. Just takes a while and sometimes patients will come in with an ultrasound already performed.
So there's really, it's a whole bag of, but certainly in our offices, we'll do an ultrasound if we think that it will add something, yeah. Labs typically TSH, if it hasn't been done, is the only thing you really need. And that's just to rule out a, you know, a toxic nodular goiter, incredibly rare in this day and age.

[Gopi Shah MD]
I assume that usually if there's a concern for a thyroid nodule, and you send them for an ultrasound thyroid you also have them scan the neck, both sides, one side?

[David Goldenberg MD]
Gopi. That's a really interesting point. I teach my residents that a thyroid ultrasound must include both sides of the neck. Because regardless of the nodule size, regardless of how benign it looks, if the patient has abnormal-looking lymphadenopathy that trumps everything. Ultrasound is excellent for looking for abnormal lymph nodes in the lateral neck.

It is not sensitive for looking for lymph nodes in the central compartment while the thyroid gland is in situ. So, you know, if they see something, that's also suspicious, but if they don't see something, it doesn't mean that it's not there. Ultrasounds are so good nowadays that we can get an inkling of the suspicion for malignancy in a thyroid nodule based on findings on ultrasound. So if someone comes in with a cystic lesion, purely cystic, the chances of this being malignant are very, very low. On the other hand, if a patient comes in with a nodule, which has, oh, microcalcifications, a hypoechoic irregular margins, taller rather than wide, mixed cystic solid component. All of these things say to me that the chances that this nodule regardless of size may be malignant. And, we'll probably take that to the next diagnostic level.

[Gopi Shah MD]
And then in terms of like workup for your nodules, you know, for some of the cases that aren't as clear cut, the example that Ash gave was a great one. Do you ever use a PET scan or is there a role for these other imaging modalities and how do you use them?

[David Goldenberg MD]
That's a wonderful question because we see this. So the vast majority of people with PET scans are people who come in with a PET scan for another malignancy and they find a solitary FDG avid nodule, and those are actually considered suspicious and need to be worked up and they are.

So the patients come in with a PET CT scan for another reason, if there's a solitary FDG avid nodule that needs to be worked up, usually they get a fine needle aspiration biopsy on the ultrasonic guidance.
In those cases, they don't need a neck CT because the neck is covered by the PET. And overwhelming, if the thyroid cancer is FDG avid, and it's a cancer, it's usually more aggressive because it means it's probably not iodine avid and the opposite. So I do remember a couple of patients who accidentally came in the young, you know, sometimes a patient will not be sent to us or to even endocrinology by a PCP because they hear the word cancer and they send it to oncology and they do a PET scan probably unnecessarily. And you see it. So this is kind of anecdotal if you will. So no, we don't send for, for our thyroid nodule for a PET scan. if I'm doing surgery on a patient that already has a thyroid cancer. Or if, a thyroid nodule, like if someone comes in with a thyroid nodule and they are complaining of compressive symptoms, my rule is that I have to be convinced that it is the thyroid nodule that is causing their compressive symptoms.

The reason being, there's an old saying, you break it, you buy it. So once you've operated on the patient, they're yours for life. And if you're taking out half their thyroid gland for no good reason, you're not going to make them happier because thyroidectomy doesn't typically cure reflux. So I'll get a CAT scan on someone who is complaining of compressive symptoms.

And I will go over the scan together with the patient, say to them, “You know what, you're right. Your massive thyroid nodule is compressing your esophagus or pushing on your trachea. Let's take out below.” or I'll say to them, “You know, your thyroid is really not that large. We have to look for another reason to explain your compressive symptoms.”

If it's a thyroid cancer, I reserve the right to do a CAT scan with contrast if I think it will help my surgical planning. Usually if there's extensive neck disease, I say I reserve the right, because in certain places, nuclear medicine, gets up in arms over the use of contrast. I think it's unwarranted personally.
We do what's right for the patient. If I think a CAT scan will help, but it's not a routine thing that I'll do for any old thyroid nodule.

[Ashley Agan MD]
And the concern is timing for post-op radioactive iodine. Is that right? They're worried that that's going to delay that treatment if they need it.

[David Goldenberg MD]
Yeah. That's the concern. Yeah, I don't buy it. First of all, it takes awhile to get the nuclear scan or the iodine treatment, at least in our neck of the woods. I'm sure the iodine from the CAT scan has washed out long ago. But in any case, my ability to perform surgery is at that point, the more important thing. It's a surgically treated disease, right?