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All right. Hello and welcome to Noon Conferences hosted by MRI online in

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response to the changes happening around the world right now in the shutting

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down of in person events. We've decided to provide free Noon Conferences

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to all radiologists worldwide. Today we are joined by Dr. Deborah Baumgarten.

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She is an abdominal radiologist focusing on ultrasound CT of benign and

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malignant GU and GI conditions. She is active in service and education,

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mentoring trainees and junior faculty, active in radiology societies and

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reviews for multiple journals. Reminder that there will be a Q&A session

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at the end of this lecture. So please use that Q&A feature to

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ask all of your questions and we'll get to as many as we

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can before our time is up. That being said, thanks for joining us

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today, Dr. Baumgarten. I'll let you take it from here.

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Hi, good afternoon. And hopefully as soon as I hit share,

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you're seeing the right screen here. Thank you for that introduction.

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I've also got the Q&A box open, so if there are questions that

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come up during the talk and I happen to see them,

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I will try to answer questions as we go along as well.

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So I'm going to be speaking to you about ultrasound to monitor thyroid

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cancer patients for recurrence after surgery. I have no disclosures.

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So my learning objectives are that by the end of the session,

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you should be able to differentiate normal reactive and malignant nodes,

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at least malignant nodes from thyroid cancer. Keep in mind that the features

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that I'm sharing with you today are pretty specific for thyroid cancer.

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So other head and neck malignancies may look a little bit different.

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I want you to be familiar with the patterns of node spread so

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that you know where to look for recurrences.

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I want you to be able to recognize the normal postoperative thyroid fossa

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in contrast to a patient who's had a local recurrence.

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And then we'll talk really briefly about the 2015 American Thyroid Association

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or ATA guidelines as they relate to the postoperative patient so that we

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can apply them in a thoughtful and consistent manner.

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So what does the ATA recommend in postoperative patients?

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So they say that the thyroid bed, the central and lateral cervical nodal

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compartments should be imaged by ultrasound every 6 12 months.

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And you should really spend a lot of time looking

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where anybody has had a previous malignant node. So if you know preoperatively

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that they had nodes at level 6 and say level 2, those are

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the areas that you tend to have recurrences again.

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The risk of nodal recurrence increases with the number of nodes that are

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involved at the initial surgery. So the larger the number involved,

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the more likely they are to have a nodal recurrence.

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If there's extra nodal extension at the time of that initial surgery,

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if they have macroscopic, described macroscopic involvement, not microscopic

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in a node, and if you have a patient who has an elevated

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thyroglobulin, those are things that should make you look really hard for

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a recurrence. And if it's going to change management, knowing whether a

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node is positive or negative, then ultrasound guided fine needle aspiration

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is recommended by the ATA for any suspicious nodes that are greater than

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about 8 10 millimeters. Smaller than that and they get harder to get

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a good sample. Although we have been asked to and have biopsy nodes

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as small as 5 millimeters if it's really going to change management.

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If they're just going to treat somebody with radioactive iodine or chemotherapy,

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or if they have widespread metastatic disease otherwise, and it's not going

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to make a difference whether a particular node is positive or negative,

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we don't need to do this. So where do we look for metastatic

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lymph nodes? So this is a schematic of the neck and we've exposed

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the musculature here, which is easier to see on CT than it is

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on ultrasound, but we can divide the neck into various compartments.

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So we have the central compartment, which is level 6, which includes the

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thyroid fossa and central lymph nodes that may be a little bit below

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the thyroid fossa. The levels 2, 3, and 4 are along the jugular

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chain and it's hard to see the landmarks that differentiate levels 2, 3,

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and 4. So I just think about it as dividing the neck into

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thirds with level 2 at the top, level 3 in the middle,

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and level 4 as you come down toward the clavicle.

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Level 1, submandibular, and level 5, which is more posterior, we tend to

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ignore those when we're doing our postoperative checks, unless the patient

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complains of something palpable or unless you know they've had a recurrence

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there before, because these areas tend to be involved less frequently.

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So what features do we look for to differentiate normal from abnormal lymph

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nodes? So normal or benign nodes, that's a start there.

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They're generally oval or elongated in shape. And you can see here,

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this is an elongated node. When we turn on it, it's not round.

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It's about 12 x 4 x 5 millimeters.

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The only exception to this nice oval shape is in the submandibular and

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submental spaces, level 1. But again, we're not going to routinely look

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there unless the patient's complaining about something. Those nodes tend

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to be a little more lobulated and a little more bizarre looking.

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The cortex is relatively hypoechoic to the surrounding soft tissues.

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We have an echogenic hilum. And if there is flow that we can

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detect, it's going to be vascularity that comes in at the hilum. Here's

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another benign node, kind of an oval, again, a hypoechoic cortex. We have

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hilar flow. We don't actually see the hilum all that well.

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The flow is going to imply where that hilum is.

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And another benign node here. We have sort of a nice trilaminar appearance

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here where we have that hypoechoic cortex and then the hilum here.

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And again, it has that oval shape and flow that is coming in

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and branching from the hilum. Reactive nodes are a brand or kind of

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benign node that are just a little bit in a hyperdrive there.

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They may be a little bit larger than regular benign nodes, but they

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remain oval or elongated. And again, that's except in the level 1, but

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again, we're not routinely looking there. The cortex remains hypoechoic.

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The hilum remains echogenic. And they tend to have increased flow.

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And now sometimes you have to be careful if your gain settings are

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really high, you may get a lot of flow in a node that

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may not be real. So if your gain settings are appropriate,

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they should have increased flow compared to a normal node. Now,

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if you see a patient who has a lot of nodes that look

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benign...