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How do we categorize the nonsolid lung nodules found

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on lung cancer screening?

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These are often called ground glass nodules, ggn,

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or ground glass opacities gls.

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So we're gonna talk about what is a nonsolid nodule,

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and we're gonna talk about the lung rads categories

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for these nonsolid nodules

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with the attendant management recommendations in long rads,

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there are really only two categories in which nonsolid

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or ground glass nodules can be found.

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Categories two and categories three.

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The size threshold difference between category two

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and category three is essential 30 millimeters.

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The first time you find a pure ground glass

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or nonsolid nodule on a baseline ct,

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or if it's new or growing.

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But under 30 millimeters, we consider

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that a category two negative screen.

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And if the nodule reaches the 30 millimeter size threshold

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on a baseline or new finding, we would consider

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that a category three.

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Once a 30 millimeter

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or greater nonsolid nodule has been shown to be

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not growing over time.

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It gets downgraded to category two.

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Why do we do this for pure nonsolid or ground glass nodules?

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Compared to the part solid and solid categories?

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We're not saying that these nodules are not cancer.

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In fact, many of these nodules are cancer.

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If you were to put them under a microscope, they represent

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adenocarcinomas with a very indolent growth pattern.

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What we're looking for in ground glass nodules

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to elevate them to a higher degree

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of recommendation like a category four X would be if their

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growth rate is accelerating,

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or if they develop a new solid component within them

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indicating that there has been a conversion from a

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relatively indolent adenocarcinoma to one

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that has an invasive solid component.

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So whenever you're looking at ground glass nodules,

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it's very important to look

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and see is there any new solid component on the CT

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that you're reading, which would be a trigger

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to indicate there's been some conversion in the way this

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adenocarcinomas behaving.

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And in that case, part solid nodules usually undergo either

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shorter term interval follow-up,

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or may proceed to surgical resection

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or other treatments such as SBRT.