Original ArticleHealth Services Resarch and PolicyManaging Incidental Findings on Thoracic CT: Lung Findings. A White Paper of the ACR Incidental Findings Committee
Section snippets
Overview of the ACR Incidental Findings Project
The core objectives of the Incidental Findings Project are to (1) develop consensus on patient characteristics and imaging features that are required to characterize an incidental finding; (2) provide guidance to manage such findings in ways that balance the risks and benefits to patients; (3) recommend reporting terms that reflect the level of confidence regarding a finding; and (4) focus future research by proposing a generalizable management framework across practice settings.
The Consensus Process: Management of Incidental Lung Findings
This article presents the recommendations from the Incidental Findings Committee (IFC) regarding incidental lung findings detected on thoracic CT. The publication is divided into two parts: (1) lung nodules and (2) other lung findings. The process of developing these recommendations included naming an overall Chest Subcommittee chair, who appointed Subcommittee members that are recognized experts in thoracic imaging. The scope of incidental thoracic findings was recognized to be large.
Elements of the Flowcharts: Color Coding
Algorithms for managing incidental findings are depicted in multiple flowcharts (Fig. 1, Fig. 2, Fig. 3, Fig. 4, Fig. 5, Fig. 6). Within each flowchart, yellow boxes indicate using or acquiring clinical data (eg, lesion size), green boxes describe recommendations for action (eg, follow-up imaging), and red boxes indicate that workup or followup may be terminated (eg, if the finding is presumed to be benign). To minimize complexity, each algorithm addresses most—but not all—imaging appearances
Inclusion and Exclusion Criteria
Patients for whom our recommendations are applicable include adults (≥35 years) who are asymptomatic and have undergone imaging for a reason unrelated to the incidental finding. The algorithm should not be applied if the patient has signs or symptoms related to the incidental finding. Radiologists should use discretion when considering patients with limited life expectancy and substantial comorbidities; further downstream care should not be pursued if patients are unable to tolerate therapy or
Imaging Protocol Optimization
In the discussion of the lung findings addressed in this article, comments apply to standard and low-dose examinations, whether performed with or without intravenous contrast. If relevant, those findings potentially affected by low-dose examinations are noted. All thoracic CT should be reconstructed into contiguous thin sections for viewing lung detail (eg, 1.0-1.5 mm) and thicker sections for overview of the lungs and soft tissues (eg, 2.0-3.0 mm).
Relevant Patient Populations
When considering management of incidental lung nodules, additional guidance concerning exclusion criteria is warranted, as detailed in the following four points. Importantly, the ACR’s IFC recommendations for incidental nodules closely follow those of Fleischner Society guidelines [3], providing clarification in specific domains.
Populations for which the IFC’s recommendations should not be used include the following:
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Recommendations do not apply for patients in a lung cancer screening program
Nature and Scope of the Problem
A pulmonary cyst is a region of low attenuation within the lung parenchyma with a wall that creates a well-defined interface with normal lung on thoracic CT [11]. Pulmonary cysts are common and likely related to aging. In one study, asymptomatic cysts were reported in 25% of patients older than 75 years and none in patients younger than 55 years [22]. Winter et al reported pulmonary cysts in 13% of patients older than 65 years but none in those 30 to 50 years old [23]. In the Framingham Heart
Take-Home Points
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We propose algorithms for managing incidental pulmonary findings, including lung nodules, pulmonary cysts, ground glass opacities, and interlobular septal thickening and reticular opacities.
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Pulmonary nodule(s) management centers on the risk of malignancy, which is primarily related to size, density, morphology, and patient risk factors.
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Pulmonary cysts are common and mostly benign but evaluation depends upon wall thickness and distribution within the lungs.
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Ground glass opacities are secondary to
References (50)
- et al.
Micronodules detected on CT during the NLST: prevalence and relation to positive studies and lung cancer
J Thorac Oncol
(2019) - et al.
Managing incidental findings on abdominal CT: white paper of the ACR incidental findings committee
J Am C Radiol
(2010) - et al.
Follow-up of small (4 mm or less) incidentally detected nodules by computed tomography in oncology patients: a retrospective review
J Thorac Oncol
(2010) - et al.
A clinical model to estimate the pretest probability of lung cancer in patients with solitary pulmonary nodules
Chest
(2007) - et al.
Evaluation of individuals with pulmonary nodules: when is it lung cancer? Diagnosis and management of lung cancer, 3rd ed: American College of Chest Physicians evidence-based clinical practice guidelines
Chest
(2013) - et al.
Limited utility of pulmonary nodule risk calculators for managing large nodules
Curr Probl Diagn Radiol
(2018) - et al.
Diagnostic criteria for idiopathic pulmonary fibrosis: a Fleischner Society White Paper
Lancet Respir Med
(2018) - et al.
Stereotactic body radiotherapy for lung tumors in patients with subclinical interstitial lung disease: the potential risk of extensive radiation pneumonitis
Lung Cancer
(2013) - et al.
Pre-existing interstitial lung abnormalities are risk factors for immune checkpoint inhibitor-induced interstitial lung disease in non-small cell lung cancer
Respir Investig
(2019) - et al.
Guidelines for management of incidental pulmonary nodules detected on CT images: from the Fleischner Society 2017
Radiology
(2017)
Decision memo for screening for lung cancer with low dose computed tomography (LDCT)
Small pulmonary lesions detected at CT: clinical importance
Radiology
The probability of malignancy in solitary pulmonary nodules. Application to small radiologically indeterminate nodules
Arch Intern Med
Probability of cancer in pulmonary nodules detected on first screening CT
N Engl J Med
Guidelines for management of small pulmonary nodules detected on CT scans: a statement from the Fleischner Society
Radiology
Recommendations for the management of subsolid pulmonary nodules detected at CT: a statement from the Fleischner Society
Radiology
Fleischner Society: glossary of terms for thoracic imaging
Radiology
Recommendations for measuring pulmonary nodules at CT: a statement from the Fleischner Society
Radiology
Evaluating variability in tumor measurements from same-day repeat CT scans of patients with non-small cell lung cancer
Radiology
CT reconstruction algorithm selection in the evaluation of solitary pulmonary nodules
J Comput Assist Tomogr
Solitary and multiple pulmonary nodules
Pulmonary hamartoma: CT findings
Radiology
Pulmonary perifissural nodules on CT scans: rapid growth is not a predictor of malignancy
Radiology
Smooth or attached solid indeterminate nodules detected at baseline CT screening in the NELSON study: cancer risk during 1 year of follow-up
Radiology
Lung morphology in the elderly: comparative CT study of subjects over 75 years old versus those under 55 years old
Radiology
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2022, Annals of Emergency MedicineCitation Excerpt :This is particularly true for radiographic findings that may not be pertinent to the current visit. The timely communication of these incidental findings to patients is important, and medical associations have provided guidelines surrounding this practice.20-22 However, there have been few examples of comprehensive systematic processes for the management of incidental findings.2,17,23
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Dr Munden reports other from Optellum, other from TheraBionics, outside the submitted work. Dr MacMahon reports personal fees from Riverain Technology, other from Hologic, grants from Bioclinica, grants from Philips Healthcare, outside the submitted work. Dr Ko reports grants from Siemens Healthineers, outside the submitted work. Dr Naidich reports personal fees from PM-Google Radiology Consulting—CLST, personal fees from IC-Radiologist Board Certified by Vituity, Inc, outside the submitted work. Dr Rossi reports speaker: Boehringer Ingelheim. Dr McAdams reports personal fees from Novartis, nonfinancial support from Pfizer, nonfinancial support from Gilead Sciences, nonfinancial support from Abbott Labs, nonfinancial support from Amgen, nonfinancial support from Johnson & Johnson, nonfinancial support from Bristol-Myers-Squibb, outside the submitted work. Dr Berland reports personal fees from Nuance, Inc; personal fees from iMedis AI, Inc; personal fees from DeepSight Technologies, Inc; and personal fees from American Medical Foundation, outside the submitted work. Dr Pandharipande reports grants from Medical Imaging and Technology Alliance, outside the submitted work. The other authors state that they have no conflict of interest related to the material discussed in this article. Dr Rossi is a partner. Dr McAdams is a partner. Dr Berland is retired from practice. Dr Munden, Dr Black, Dr Hartman, Dr MacMahon, Dr Ko, Dr Dyer, Dr Naidich, Dr Goodman, Dr Brown, Dr Kent, Dr Carter, Dr Chiles, Dr Leung, Dr Boiselle, Dr Kazerooni, and Dr Pandharipande are faculty.