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An important part of interpreting lung cancer screening CT

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are incidental findings, things that are not related

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to finding lung cancer but may be significant for a patient.

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We're gonna talk about an approach

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to incidental findings on lung cancer screening cts,

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how often we see them,

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the most common management recommendations,

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and the ACRs quick reference guide

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to incidental findings on lung cancer screening CT exams.

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We have been doing chest cts

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for much longer than lung cancer screening has been about,

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and we find findings on chest cts in almost any organ system

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on the examinations, so it's not surprising.

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This is an important topic in lung cancer screening.

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cts also, patients coming

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for lung cancer screening CT are supposed to be asymptomatic

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for purposes of lung cancer,

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but their risk factor of cigarette smoking

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increases the findings of other entities

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that may be impactful on their health.

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The goal of incidental finding detection is to reduce risk

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to patients from additional unnecessary exams,

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including the risk of radiation

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and associate interventional procedures.

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In other words, when do you need to do something

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and when don't you need to do something limiting the cost

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of management to patients in the healthcare system

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by only recommending follow up for things that are important

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to do so we achieve greater consistency when we apply common

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standards for reporting and managing incidental findings is

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an important component of the quality

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of our radiology practice.

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Incidental findings, recommendations help provide guidance

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to radiologists concerned about the risk of litigation

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for missing incidental findings that later prove

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to be clinically important.

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In other words, when should a radiologist

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recommend follow-up or testing or additional diagnostics

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and when not to is an important concern.

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We see many incidental findings on chest cts, particularly

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as the resolution is improved over time

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by having classifications for incidental findings.

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It also helps us look at the evidence and try

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and improve the evidence over time.

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So have we seen with many

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of the ACRs sent findings white papers

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as people have applied some

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of the recommendations they've learned?

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They may work in some circumstances but not in others,

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and that's led to improvements in the incidental findings.

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Recommendations through studying?

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Well, what is an incidental finding?

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Some people call it an incidental oma,

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and it's defined as an incidental abnormality detected on

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imaging that was not due

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to the reason the exam was performed.

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The increase in the use

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of cross-section imaging examination has led

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to a marked increase in the numbers of these

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that we've detected in addition

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to the improvements in the imaging technology

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and their sensitivity for abnormalities.

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Now, the A CR has a committee that's specifically focused on

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incidental findings and has representation from all

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of the different subspecialties in radiology,

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and they have published over a dozen white papers

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on incidental findings.

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Some of these are relevant to lung cancer screening,

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including managing incidental findings on thoracic ct.

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That covers the media signum

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and cardiovascular findings that came out in 2018,

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and we followed with a paper on findings

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that are in the lungs that are incidental,

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and it's from these two that we draw some

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of the recommendations

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for incidental findings management on lung cancer screening

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cts, the first one on managing mediastinal

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and cardiovascular findings is important specifically

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for things like mediastinal masses

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and aortic aneurysms, coronary trail calcification

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and pulmonary arterial abnormalities.

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The second paper looks at both diffuse interstitial

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and obstructive lung disease, including lung cysts.

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Now, how often do we see

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S modifier findings on lung cancer screening CTE exams,

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these findings that are significant

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or potentially significant and where we add this S modifier?

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Well, we looked at the first 1.75 million screening exams

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entered into the a's lung cancer screening registry,

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and 19% of patients had one or more S category.

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Incidental finding, 15.6% of screening exams had one such,

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finding 2.2% had two findings,

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and about half a percent had three or more significant

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or potentially significant in central findings.

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If we look at what the most common findings are,

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looking at the screens,

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coronary artery calcification was the most

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common incidental finding.

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We recommend that in lung RADS reporting schema

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that moderate or severe coronary artery calcification be

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codified as an S.

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Finding masses were the second most common finding found in

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2.8% of all the screening cts

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and then interstitial lung disease

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or pulmonary fibrosis,

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which were just under 3% emphysema.

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There's controversy about is it

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or is it not an S finding patients who smoke cigarette C

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or increased risk of emphysema?

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So many people have considered mild emphysema

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and mild small airway disease

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or wall thickening, not something

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that they would consider an S finding

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because it's expected in that truly incidental,

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and some people would consider

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that we should only report emphysema

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as an S finding if it's moderate or severe.

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Now, I think the management of COPD

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and early detection diagnosis is changing,

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just like lung cancer screening is changing.

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And now some of the recommendations are coming out

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of large trials such as COPD gene

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and working with pulmonary medicine where

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milder findings are recommended to be coded as zest findings

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and to suggest patients have pulmonary function testing

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as patients often don't report symptoms

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or think of their symptoms as being related to COPD.

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So emphysema is a rapidly changing space,

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and I think this 1.2% represents the old caveat

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of only reported as an S finding if it's moderate

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or severe aortic aneurysms occurring in about

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1% of patients.

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If we look at all of the studies that had an S modifier,

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62% of the S modifier cases were coronary calcium

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and 15% masses.