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Let's take a look at this lung cancer screening CT exam.

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Here we are looking at the lung windows

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and we see some mild bi apical scar

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and some subpleural apical blobs.

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Pretty common findings in older individuals

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who have the eligibility age for lung cancer screening

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and we see some more subpleural blobs

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or areas of paraseptal emphysema.

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And then right here at the right apex

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we're finding a ground glass nodule.

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We can measure that nodule.

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We're getting just under 10 millimeters, nine,

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10 millimeters in diameter.

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So let's keep looking throughout the lungs

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for any other pulmonary nodules.

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We see a little bit of central lobular emphysema,

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some low density holes with

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that well-defined walls a little bit more paraseptal

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emphysema, these little subpleural lucencies.

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We said that these small airway walls are a little bit

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thickened relative to the size of the airway lumen.

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Pretty common finding individuals who smoke

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and early evidence of small airway disease, a form of COPD.

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Again, we can see centrally here this moderate small

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airway wall thickening.

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We've got some mild dependent atelectasis

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that's a little bit of round glass looking

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slightly reticular abnormality

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that is in the posterior most aspect of the lungs.

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Um, we know that dependent atelectasis is more common in

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individuals who smoke

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and it's also more common with increasing age.

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So we see this very commonly in individuals who come

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for lung cancer screening.

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I like to say that whatever part

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of the lung is up against the CT table,

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which you can see right here, is essentially splinted

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during a chest ct.

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And so when you take a breath in the anterior part

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of the lung that's away from the table moves up

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and down a lot, but the posterior lung is basically

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fixed up against the table.

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So not surprising, you have dependent ectasis

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and as we know for things like prone imaging and HCTs,

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but a lot of this goes away if a patient replaced prone.

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So seeing more of this small airway wall thickening,

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this airway type of COPD

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and then the airways really peter out very quickly

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with almost no little lumen left in them.

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So airway centered COPD

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and then we come back up here to this ground glass nodule.

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So as we mentioned, the size threshold for

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category two versus category three

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for ground glass nodules is 30 millimeters under 30

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millimeter nodules will be considered a category two

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A finding in lung rats.

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And the recommendation is to continue annual screening ct.

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Now let's take a look at

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what happened in this patient over time.

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We have serial CT exams here on the bottom.

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Let's scroll up to that nodule.

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And we have the nodule that we see on this current exam.

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This nine and a half millimeter right apical ground glass

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nodule three years later on the CT

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Screening, it's about the same size, minimally larger,

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another three years later still hasn't changed.

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But as we continue to follow this exam,

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and this is 2023 compared

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to the initial screening exam I showed you from 2015.

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Now we've had a change in the biologic

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behavior of this nodule.

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It's been fairly stable since 20 15, 20 18, 20 21.

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But now it is uh, significantly increased in its size

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and it's also increased in density.

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We're gonna look very closely to see within this nodule.

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Now are there any solid components?

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Does this move from a ground glass

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or nonsolid nodule into the part solid nodule?

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I think most people would call this a pure ground glass

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or nonsolid nodule.

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Next step, um, with this is, is this still a lung RADS two?

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Well, it's still under that 30 millimeter thigh threshold

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but it hasn't crossed that territory.

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So most people would continue to call this a long RADS two

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and the patient would come back

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for their next annual screening in 12 months.

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Now if you're trying to deliver personalized patient

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tailored care, you know pulmonary medicine physician seeing

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this patient may say, you know, it has been stable over time

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but now it's demonstrated a significant growth change in the

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last two years and might get concerned about that

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because it's primarily a nonsolid nodule

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with no solid component.

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There really is no role

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for PET ct And the further assessment of this type

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of a nodule, at most we might consider doing

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a shorter term followup CT

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if there's more concern maybe in six months.

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The problem with a three month followup cts is

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unless you have enough of a solid component,

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it's generally very hard to to identify growth

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with two short of timeframe.

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But this patient is scheduled

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for their next annual lung cancer screening CT this summer

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and we'll be carefully watching this nodule to see

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that hopefully it hasn't changed

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and if it has grown, identify that rate

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of growth which can be used to help understand risk

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for the individual patient.

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So pure ground glass nodule under three centimeters,

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be entire time across its journey even though it is

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most recently increased in size.

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Remains long. RADS two with a recommendation

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for a follow-up annual CT screening in 12 months.

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Ground glass nodules

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that are lung cancer are usually relatively indolent

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adenocarcinomas, but they can demonstrate change in their

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growth and aggressiveness,

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particularly when they develop a solid component.