Extrapulmonary Findings and Malignancies in Participants Screened With Chest CT in the National Lung Screening Trial

Pros and cons of reporting incidental findings in lung cancer screening

Incidental findings (IFs) are common in lung cancer screening (LCS). While the detection of some of these findings can lead to early diagnosis and treatment of clinically significant conditions, it also carries the risks of overdiagnosis and overtreatment, causing anxiety for patients and increased economic costs for health systems. Effective management of IFs requires a balanced approach guided by clear guidelines, standardized reporting, and participants-centered communication. As the field of LCS evolves, continued research and innovation will be essential in refining the strategies for managing IFs, ensuring that the benefits of screening are maximized while minimizing potential harm. Evidence-based guidelines on reporting and management of IFs, however, are still lacking. This narrative review explores the pros and cons of reporting IFs in LCS, focusing on key controversies. KEY POINTS: Reporting and managing incidental findings in lung cancer screening is largely debated. The detection of incidental findings can lead to early diagnosis of clinically significant conditions but carries the risks of overdiagnosis and overtreatment. A balance must be found to have a positive impact on the population while not placing a burden on healthcare systems.

Clinicians' Agreement on Extrapulmonary Radiographic Findings in Chest X-Rays Using a Diagnostic Labelling Scheme

Objective: Reliable reading and annotation of chest X-ray (CXR) images are essential for both clinical decision-making and AI model development. While most of the literature emphasizes pulmonary findings, this study evaluates the consistency and reliability of annotations for extrapulmonary findings, using a labelling scheme. Methods: Six clinicians with varying experience levels (novice, intermediate, and experienced) annotated 100 CXR images using a diagnostic labelling scheme, in two rounds, separated by a three-week washout period. Annotation consistency was assessed using Randolph's free-marginal kappa (RK), prevalence- and bias-adjusted kappa (PABAK), proportion positive agreement (PPA), and proportion negative agreement (PNA). Pairwise comparisons and the McNemar's test were conducted to assess inter-reader and intra-reader agreement. Results: PABAK values indicated high overall grouped labelling agreement (novice: 0.86, intermediate: 0.90, experienced: 0.91). PNA values demonstrated strong agreement on negative findings, while PPA values showed moderate-to-low consistency in positive findings. Significant differences in specific agreement emerged between novice and experienced clinicians for eight labels, but there were no significant variations in RK across experience levels. The McNemar's test confirmed annotation stability between rounds. Conclusions: This study demonstrates that clinician annotations of extrapulmonary findings in CXR are consistent and reliable across different experience levels using a pre-defined diagnostic labelling scheme. These insights aid in optimizing training strategies for both clinicians and AI models.

Lung Cancer Screening and Incidental Findings: A Research Agenda: An Official American Thoracic Society Research Statement

Background: Lung cancer screening with low-dose computed tomography (LDCT) may uncover incidental findings (IFs) unrelated to lung cancer. There may be potential benefits from identifying clinically significant IFs that warrant intervention and potential harms related to identifying IFs that are not clinically significant but may result in additional evaluation, clinician effort, patient anxiety, complications, and excess cost. Objectives: To identify knowledge and research gaps and develop and prioritize research questions to address the approach to and management of IFs. Methods: We convened a multidisciplinary panel to review the available literature on IFs detected in lung cancer screening LDCT examinations, focusing on variability and standardizing reporting, management of IFs, and evaluation of the benefits and harms of IFs, particularly cardiovascular-related IFs. We used a three-round modified Delphi process to prioritize research questions. Results: This statement identifies knowledge gaps in 1) reporting of IFs, 2) management of IFs, and 3) identifying and reporting coronary artery calcification found on lung cancer screening LDCT. Finally, we present the panel's initial 36 research questions and the final 20 prioritized questions. Conclusions: This statement provides a prioritized research agenda to further efforts focused on evaluating, managing, and increasing awareness of IFs in lung cancer screening.

The pros and cons of lung cancer screening

Several trials have shown that low-dose computed tomography-based lung cancer screening (LCS) allows a substantial reduction in lung cancer-related mortality, carrying the potential for other clinical benefits. There are, however, some uncertainties to be clarified and several aspects to be implemented to optimize advantages and minimize the potential harms of LCS. This review summarizes current evidence on LCS, discussing some of the well-established and potential benefits, including lung cancer (LC)-related mortality reduction and opportunity for smoking cessation interventions, as well as the disadvantages of LCS, such as overdiagnosis and overtreatment. CLINICAL RELEVANCE STATEMENT: Different perspectives are provided on LCS based on the updated literature. KEY POINTS: Lung cancer is a leading cancer-related cause of death and screening should reduce associated mortality. This review summarizes current evidence related to LCS. Several aspects need to be implemented to optimize benefits and minimize potential drawbacks of LCS.

The American Cancer Society National Lung Cancer Roundtable strategic plan: Implementation of high-quality lung cancer screening

More than a decade has passed since researchers in the Early Lung Cancer Action Project and the National Lung Screening Trial demonstrated the ability to save lives of high-risk individuals from lung cancer through regular screening by low dose computed tomography scan. The emergence of the most recent findings in the Dutch-Belgian lung-cancer screening trial (Nederlands-Leuvens Longkanker Screenings Onderzoek [NELSON]) further strengthens and expands on this evidence. These studies demonstrate the benefit of integrating lung cancer screening into clinical practice, yet lung cancer continues to lead cancer mortality rates in the United States. Fewer than 20% of screen eligible individuals are enrolled in lung cancer screening, leaving millions of qualified individuals without the standard of care and benefit they deserve. This article, part of the American Cancer Society National Lung Cancer Roundtable (ACS NLCRT) strategic plan, examines the impediments to successful adoption, dissemination, and implementation of lung cancer screening. Proposed solutions identified by the ACS NLCRT Implementation Strategies Task Group and work currently underway to address these challenges to improve uptake of lung cancer screening are discussed. PLAIN LANGUAGE SUMMARY: The evidence supporting the benefit of lung cancer screening in adults who previously or currently smoke has led to widespread endorsement and coverage by health plans. Lung cancer screening programs should be designed to promote high uptake rates of screening among eligible adults, and to deliver high-quality screening and follow-up care.

AI for Multistructure Incidental Findings and Mortality Prediction at Chest CT in Lung Cancer Screening

Background Incidental extrapulmonary findings are commonly detected on chest CT scans and can be clinically important. Purpose To integrate artificial intelligence (AI)-based segmentation for multiple structures, coronary artery calcium (CAC), and epicardial adipose tissue with automated feature extraction methods and machine learning to detect extrapulmonary abnormalities and predict all-cause mortality (ACM) in a large multicenter cohort. Materials and Methods In this post hoc analysis, baseline chest CT scans in patients enrolled in the National Lung Screening Trial (NLST) from August 2002 to September 2007 were included from 33 participating sites. Per scan, 32 structures were segmented with a multistructure model. For each structure, 15 clinically interpretable radiomic features were quantified. Four general codes describing abnormalities reported by NLST radiologists were applied to identify extrapulmonary significant incidental findings on the CT scans. Death at 2-year and 10-year follow-up and the presence of extrapulmonary significant incidental findings were predicted with ensemble AI models, and individualized structure risk scores were evaluated. Area under the receiver operating characteristic curve (AUC) analysis was used to evaluate the performance of the models for prediction of ACM and extrapulmonary significant incidental findings. The Pearson χ2 test and Kruskal-Wallis rank sum test were used for statistical analyses. Results A total of 24 401 participants (median age, 61 years [IQR, 57-65 years]; 14 468 male) were included. In 3880 of 24 401 participants (16%), 4283 extrapulmonary significant incidental findings were reported. During the 10-year follow-up, 3389 of 24 401 participants (14%) died. CAC had the highest feature importance for predicting the three study end points. The 10-year ACM model demonstrated the best AUC performance (0.72; per-year mortality of 2.6% above and 0.8% below the risk threshold), followed by 2-year ACM (0.71; per-year mortality of 1.13% above and 0.3% below the risk threshold) and prediction of extrapulmonary significant incidental findings (0.70; probability of occurrence of 25.4% above and 9.6% below the threshold). Conclusion A fully automated AI model indicated extrapulmonary structures at risk on chest CT scans and predicted ACM with explanations. ClinicalTrials.gov Identifier: NCT00047385 © RSNA, 2024 Supplemental material is available for this article. See also the editorial by Yanagawa and Hata in this issue.

WFUMB Review Paper. Incidental Findings in Otherwise Healthy Subjects, How to Manage: Liver

An incidental focal liver lesion (IFLL) is defined as a hepatic lesion identified in a patient imaged for an unrelated reason. They are frequently encountered in daily practice, sometimes leading to unnecessary, invasive and potentially harmful follow-up investigations. The clinical presentation and the imaging aspects play an important role in deciding if, and what further evaluation, is needed. In low-risk patients (i.e., without a history of malignant or chronic liver disease or related symptoms), especially in those younger than 40 years old, more than 95% of IFLLs are likely benign. Shear Wave liver Elastography (SWE) of the surrounding liver parenchyma should be considered to exclude liver cirrhosis and for further risk stratification. If an IFLL in a low-risk patient has a typical appearance on B-mode ultrasound of a benign lesion (e.g., simple cyst, calcification, focal fatty change, typical hemangioma), no further imaging is needed. Contrast-Enhanced Ultrasound (CEUS) should be considered as the first-line contrast imaging modality to differentiate benign from malignant IFLLs, since it has a similar accuracy to contrast-enhanced (CE)-MRI. On CEUS, hypoenhancement of a lesion in the late vascular phase is characteristic for malignancy. CE-CT should be avoided for characterizing probable benign FLL and reserved for staging once a lesion is proven malignant. In high-risk patients (i.e., with chronic liver disease or an oncological history), each IFLL should initially be considered as potentially malignant, and every effort should be made to confirm or exclude malignancy. US-guided biopsy should be considered in those with unresectable malignant lesions, particularly if the diagnosis remains unclear, or when a specific tissue diagnosis is needed.

Incidence and Management of Cardiothoracic Relevant Extrapulmonary Findings Found on Low-Dose Computed Tomography

BACKGROUND

We aimed to investigate the incidence of extrapulmonary findings identified on low-dose computed tomography (CT) that may warrant evaluation by cardiothoracic surgeons and describe their management and referral patterns at our institution.

METHODS

We conducted a retrospective cohort study of patients who underwent low-dose CT through a centralized Lung Cancer Screening Program at Thomas Jefferson University Hospital between January 2018 and December 2022. An electronic medical record review was performed for patients with incidental findings. Demographic, workup, referral, and management data were collected.

RESULTS

Of 2285 patients who underwent low-dose CT, 368 (16%) had an extrapulmonary finding that may have an indication for clinical evaluation by a cardiothoracic surgeon. The most common incidental finding was a hiatal hernia, with a prevalence of 6.3% (144 of 2285), followed by ascending thoracic aneurysms, with a prevalence of 3.6% (82 of 2285), and small pericardial effusions, with a prevalence of 1.2% (28 of 2285). Of the patients with symptomatic hiatal hernias, 29% (14 of 48) were referred to a cardiothoracic surgeon compared with only 6.25% (6 of 96) in the asymptomatic group. Of the patients with thoracic aneurysms, 48% (39 of 82) had aneurysms ≥4.2 cm. Of the ≥4.2 cm group, 18% (7 of 39) were monitored by a cardiothoracic surgeon compared with 11.6% (5 of 43) in patients with aneurysms <4.2 cm.

CONCLUSIONS

Hiatal hernias and ascending thoracic aneurysms were the 2 most prevalent incidental findings identified on low-dose CT during lung cancer screening. We demonstrated potential gaps in hiatal hernia referral patterns. Referring patients with thoracic aneurysms to cardiothoracic surgeons may not be initially warranted.

Thyroid abnormalities identified on CT screening for lung cancer

PURPOSE

Because incidental thyroid nodules (ITNs) are common extrapulmonary findings in low-dose computed tomography (LDCT) scans for lung cancer screening, we aimed to investigate the frequency of ITNs on LDCT scans separately on baseline and annual repeat scans, the frequency of malignancy among the ITNs, and any association with demographic, clinical, CT characteristics.

METHODS

Retrospective case series of all 2309 participants having baseline and annual repeat screening in an Early Lung and Cardiac Action Program (MS-ELCAP) LDCT lung screening program from January 2010 to December 2016 was performed. Frequency of ITNs in baseline and annual repeat rounds were determined. Multivariable regression analysis was performed to identify significant predictors.

RESULTS

Dominant ITNs were seen in 2.5 % of 2309 participants on baseline and in 0.15 % of participants among 4792 annual repeat LDCTs. The low incidence of new ITNs suggests slow growth as it would take approximately an average of 16.8 years for a new ITN to be detected on annual rounds of screening. Newly detected ITNs on annual repeat LDCT were all smaller than 15 mm. Regression analysis showed that the increasing of age, coronary artery calcifications score and breast density grade were significant predictors for females having an ITN. No significant predictors were found for ITNs in males.

CONCLUSION

ITNs are detected at LDCT however, no malignancy was found. Certain predictors for ITNs in females have been identified including breast density, which may point towards a common causal pathway.

ACR Lung-RADS v2022: Assessment Categories and Management Recommendations

The ACR created the Lung CT Screening Reporting and Data System (Lung-RADS) in 2014 to standardize the reporting and management of screen-detected pulmonary nodules. Lung-RADS was updated to version 1.1 in 2019 and revised size thresholds for nonsolid nodules, added classification criteria for perifissural nodules, and allowed for short-interval follow-up of rapidly enlarging nodules that may be infectious in etiology. Lung-RADS v2022, released in November 2022, provides several updates including guidance on the classification and management of atypical pulmonary cysts, juxtapleural nodules, airway-centered nodules, and potentially infectious findings. This new release also provides clarification for determining nodule growth and introduces stepped management for nodules that are stable or decreasing in size. This article summarizes the current evidence and expert consensus supporting Lung-RADS v2022.

ACR Lung-RADS v2022: Assessment Categories and Management Recommendations

The American College of Radiology created the Lung CT Screening Reporting and Data System (Lung-RADS) in 2014 to standardize the reporting and management of screen-detected pulmonary nodules. Lung-RADS was updated to version 1.1 in 2019 and revised size thresholds for nonsolid nodules, added classification criteria for perifissural nodules, and allowed for short-interval follow-up of rapidly enlarging nodules that may be infectious in etiology. Lung-RADS v2022, released in November 2022, provides several updates including guidance on the classification and management of atypical pulmonary cysts, juxtapleural nodules, airway-centered nodules, and potentially infectious findings. This new release also provides clarification for determining nodule growth and introduces stepped management for nodules that are stable or decreasing in size. This article summarizes the current evidence and expert consensus supporting Lung-RADS v2022.

Trends in the characteristics and perioperative outcomes of patients undergoing laparoscopic and open resections for benign liver lesions: An international multicenter retrospective cohort study of 845 patients

BACKGROUND

Solid benign liver lesions (BLL) are increasingly discovered, but clear indications for surgical treatment are often lacking. Concomitantly, laparoscopic liver surgery is increasingly performed. The aim of this study was to assess if the availability of laparoscopic surgery has had an impact on the characteristics and perioperative outcomes of patients with BLL.

METHODS

This is a retrospective international multicenter cohort study, including patients undergoing a laparoscopic or open liver resection for BLL from 19 centers in eight countries. Patients were divided according to the time period in which they underwent surgery (2008-2013, 2014-2016, and 2017-2019). Unadjusted and risk-adjusted (using logistic regression) time-trend analyses were performed. The primary outcome was textbook outcome (TOLS), defined as the absence of intraoperative incidents ≥ grade 2, bile leak ≥ grade B, severe complications, readmission and 90-day or in-hospital mortality, with the absence of a prolonged length of stay added to define TOLS+.

RESULTS

In the complete dataset comprised of patients that underwent liver surgery for all indications, the proportion of patients undergoing liver surgery for benign disease remained stable (12.6% in the first time period, 11.9% in the second time period and 12.1% in the last time period, p = 0.454). Overall, 845 patients undergoing a liver resection for BLL in the first (n = 374), second (n = 258) or third time period (n = 213) were included. The rates of ASA-scores≥3 (9.9%-16%,p < 0.001), laparoscopic surgery (57.8%-77%,p < 0.001), and Pringle maneuver use (33.2%-47.2%,p = 0.001) increased, whereas the length of stay decreased (5 to 4 days,p < 0.001). There were no significant changes in the TOLS rate (86.6%-81.3%,p = 0.151), while the TOLS + rate increased from 41.7% to 58.7% (p < 0.001). The latter result was confirmed in the risk-adjusted analyses (aOR 1.849,p = 0.004).

CONCLUSION

The surgical treatment of BLL has evolved with an increased implementation of the laparoscopic approach and a decreased length of stay. This evolution was paralleled by stable TOLS rates above 80% and an increase in the TOLS + rate.

Variation in Reporting of Incidental Findings on Initial Lung Cancer Screening and Associations With Clinician Assessment

PURPOSE

The aim of this study was to quantify the distribution, frequency, and clinical significance of incidental findings (IFs) on initial lung cancer screening (LCS) and the association of report characteristics with subsequent assessment.

METHODS

Health records of patients undergoing initial LCS from 2015 to 2018 in the Minneapolis VA Health Care System were retrospectively reviewed for demographics, Lung CT Screening Reporting & Data System coding, IFs, and subsequent clinical assessment. IFs were considered potentially significant if they were likely to require any follow-up. High-risk significant IFs (SIFs) were potentially malignant. The primary outcome was the SIF being addressed. Outcomes were analyzed using a mixed-effects model.

RESULTS

Patients (n = 901) were primarily male (94.1%) smokers (62.1%) with a mean age of 65.2 years. IFs were extremely common (93.9%), with an average of 2.6 IFs per scan (n = 2,296). Seven hundred eighty-six IFs (34.2%) were deemed likely SIFs, of which 58 (7.4%) were high risk. Two hundred twenty-two (28.2%) were addressed by clinicians, of which 104 (13.2%) underwent testing. Reporting of SIFs varied among radiologists, with at least one SIF in the impression in 24% to 78% of low-dose CT studies with the S modifier, used to indicate the presence of a SIF, applied to 0% to 51% of reports. In the mutually adjusted model, radiologist recommendation (adjusted odds ratio [OR], 4.67; 95% confidence interval [CI], 2.23-9.76), high-risk finding (adjusted OR, 4.35; 95% CI, 1.81-10.45), and reporting in the impression (adjusted OR, 2.58; 95% CI, 1.28-5.18) were associated with increased odds of the SIF's being addressed.

CONCLUSIONS

Radiologists vary in their reporting of IFs on LCS. Further standardization of reporting of SIFs may improve this process, with the simultaneous goals of generating appropriate testing when needed and minimizing low-value care.

Ultrasound tissue scatterer distribution imaging: An adjunctive diagnostic tool for shear wave elastography in characterizing focal liver lesions

OBJECTIVES

Focal liver lesion (FLL) is a prevalent finding in cross-sectional imaging, and distinguishing between benign and malignant FLLs is crucial for liver health management. While shear wave elastography (SWE) serves as a conventional quantitative ultrasound tool for evaluating FLLs, ultrasound tissue scatterer distribution imaging (TSI) emerges as a novel technique, employing the Nakagami statistical distribution parameter to estimate backscattered statistics for tissue characterization. In this prospective study, we explored the potential of TSI in characterizing FLLs and evaluated its diagnostic efficacy with that of SWE.

METHODS

A total of 235 participants (265 FLLs; the study group) were enrolled to undergo abdominal examinations, which included data acquisition from B-mode, SWE, and raw radiofrequency data for TSI construction. The area under the receiver operating characteristic curve (AUROC) was used to evaluate performance. A dataset of 20 patients (20 FLLs; the validation group) was additionally acquired to further evaluate the efficacy of the TSI cutoff value in FLL characterization.

RESULTS

In the study group, our findings revealed that while SWE achieved a success rate of 49.43 % in FLL measurements, TSI boasted a success rate of 100 %. In cases where SWE was effectively implemented, the AUROCs for characterizing FLLs using SWE and TSI stood at 0.84 and 0.83, respectively. For instances where SWE imaging failed, TSI achieved an AUROC of 0.78. Considering all cases, TSI presented an overall AUROC of 0.81. There was no statistically significant difference in AUROC values between TSI and SWE (p > 0.05). In the validation group, using a TSI cutoff value of 0.67, the AUROC for characterizing FLLs was 0.80.

CONCLUSIONS

In conclusion, ultrasound TSI holds promise as a supplementary diagnostic tool to SWE for characterizing FLLs.

The radiology quality assurance process in the Yorkshire Lung Screening Trial, and findings from the baseline round of low dose CT screening for lung cancer

OBJECTIVE

As lung cancer screening is rolled-out, there is a need to develop an effective quality assurance (QA) framework around radiology reporting to ensure optimal implementation. Here, we report a structured QA process for low-dose CT (LDCT) scans performed in the Yorkshire Lung Screening Trial.

METHODS

Negative LDCT scans were single read after using computer-aided detection software. The radiology QA process included reviewing 5% of negative scans selected at random, and all cases with a subsequent diagnosis of extrapulmonary cancer or interval lung cancer not detected on the baseline scan. Radiologists were not informed of the reason for review and original radiology reports were scored as either "satisfactory", "satisfactory with learning points", or "unsatisfactory".

RESULTS

From 6650 participants undergoing LDCT screening, 208 negative scans were reviewed alongside 11 cases with subsequent extrapulmonary cancer and 10 cases with interval lung cancer. Overall, only three reports were ultimately judged "unsatisfactory", 1% of randomly selected negative scans (n = 2/208) and one interval lung cancer scan (n = 1/10). Four out of a total of five cases judged "satisfactory with learning points" were related to oesophageal abnormalities where the participant was subsequently diagnosed with oesophageal cancer.

CONCLUSION

The described process attempts to minimise bias in retrospective review of screening scans, and may represent a framework for future QA of national screening programmes.

ADVANCES IN KNOWLEDGE

This study describes a structured QA process for a lung cancer screening programme, involving blinded second-read of LDCT screening scans to ensure fair, constructive audit of clinical performance.

ERS/ESTS/ESTRO/ESR/ESTI/EFOMP statement on management of incidental findings from low dose CT screening for lung cancer

BACKGROUND

Screening for lung cancer with low radiation dose computed tomography has a strong evidence base, is being introduced in several European countries and is recommended as a new targeted cancer screening programme. The imperative now is to ensure that implementation follows an evidence-based process that will ensure clinical and cost effectiveness. This European Respiratory Society (ERS) task force was formed to provide an expert consensus for the management of incidental findings which can be adapted and followed during implementation.

METHODS

A multi-European society collaborative group was convened. 23 topics were identified, primarily from an ERS statement on lung cancer screening, and a systematic review of the literature was conducted according to ERS standards. Initial review of abstracts was completed and full text was provided to members of the group for each topic. Sections were edited and the final document approved by all members and the ERS Science Council.

RESULTS

Nine topics considered most important and frequent were reviewed as standalone topics (interstitial lung abnormalities, emphysema, bronchiectasis, consolidation, coronary calcification, aortic valve disease, mediastinal mass, mediastinal lymph nodes and thyroid abnormalities). Other topics considered of lower importance or infrequent were grouped into generic categories, suitable for general statements.

CONCLUSIONS

This European collaborative group has produced an incidental findings statement that can be followed during lung cancer screening. It will ensure that an evidence-based approach is used for reporting and managing incidental findings, which will mean that harms are minimised and any programme is as cost-effective as possible.

ERS/ESTS/ESTRO/ESR/ESTI/EFOMP statement on management of incidental findings from low dose CT screening for lung cancer

BACKGROUND

Screening for lung cancer with low radiation dose computed tomography has a strong evidence base, is being introduced in several European countries and is recommended as a new targeted cancer screening programme. The imperative now is to ensure that implementation follows an evidence-based process that will ensure clinical and cost effectiveness. This European Respiratory Society (ERS) task force was formed to provide an expert consensus for the management of incidental findings which can be adapted and followed during implementation.

METHODS

A multi-European society collaborative group was convened. 23 topics were identified, primarily from an ERS statement on lung cancer screening, and a systematic review of the literature was conducted according to ERS standards. Initial review of abstracts was completed and full text was provided to members of the group for each topic. Sections were edited and the final document approved by all members and the ERS Science Council.

RESULTS

Nine topics considered most important and frequent were reviewed as standalone topics (interstitial lung abnormalities, emphysema, bronchiectasis, consolidation, coronary calcification, aortic valve disease, mediastinal mass, mediastinal lymph nodes and thyroid abnormalities). Other topics considered of lower importance or infrequent were grouped into generic categories, suitable for general statements.

CONCLUSIONS

This European collaborative group has produced an incidental findings statement that can be followed during lung cancer screening. It will ensure that an evidence-based approach is used for reporting and managing incidental findings, which will mean that harms are minimised and any programme is as cost-effective as possible.

Invasive Procedures Associated With Lung Cancer Screening in Clinical Practice

BACKGROUND

The harm associated with imaging abnormalities related to lung cancer screening (LCS) is not well documented, especially outside the clinical trial and academic setting.

RESEARCH QUESTION

What is the frequency of invasive procedures and complications associated with a community based LCS program, including procedures for false-positive and benign, but clinically important, incidental findings?

STUDY DESIGN AND METHODS

We performed a single-center retrospective study of an LCS program at a nonuniversity teaching hospital from 2016 through 2019 to identify invasive procedures prompted by LCS results, including their indication and complications.

RESULTS

Among 2,003 LCS participants, 58 patients (2.9%) received a diagnosis of lung cancer and 71 patients (3.5%) received a diagnosis of any malignancy. Invasive procedures were performed 160 times in 103 participants (5.1%), including 1.7% of those without malignancy. Eight invasive procedures (0.4% of participants), including four surgeries (12% of diagnostic lung resections), were performed for false-positive lung nodules. Only 1% of Lung Imaging Reporting and Data System category 4A nodules that proved benign were subject to an invasive procedure. Among those without malignancy, an invasive procedure was performed in eight participants for extrapulmonary false-positive findings (0.4%) and in 19 participants (0.9%) to evaluate incidental findings considered benign but clinically important. Procedures for the latter indication resulted in treatment, change in management, or diagnosis in 79% of individuals. Invasive procedures in those without malignancy resulted in three complications (0.15%). Seventy nonsurgical procedures (6% complication rate) and 48 thoracic surgeries (4% major complication rate) were performed in those with malignancy.

INTERPRETATION

The use of invasive procedures to resolve false-positive findings was uncommon in the clinical practice of a nonuniversity LCS program that adhered to a nodule management algorithm and used a multidisciplinary approach. Incidental findings considered benign but clinically important resulted in invasive procedure rates that were similar to those for false-positive findings and frequently had clinical value.

Significant Incidental Findings in the National Lung Screening Trial

Importance

Low-dose computed tomography (LDCT) lung screening has been shown to reduce lung cancer mortality. Significant incidental findings (SIFs) have been widely reported in patients undergoing LDCT lung screening. However, the exact nature of these SIF findings has not been described.

Objective

To describe SIFs reported in the LDCT arm of the National Lung Screening Trial and classify SIFs as reportable or not reportable to the referring clinician (RC) using the American College of Radiology's white papers on incidental findings.

Design, Setting, and Participants

This was a retrospective case series study of 26 455 participants in the National Lung Screening Trial who underwent at least 1 screening examination with LDCT. The trial was conducted from 2002 to 2009, and data were collected at 33 US academic medical centers.

Main Outcomes and Measures

Significant incident findings were defined as a final diagnosis of a negative screen result with significant abnormalities that were not suspicious for lung cancer or a positive screen result with emphysema, significant cardiovascular abnormality, or significant abnormality above or below the diaphragm.

Results

Of 26 455 participants, 10 833 (41.0%) were women, the mean (SD) age was 61.4 (5.0) years, and there were 1179 (4.5%) Black, 470 (1.8%) Hispanic/Latino, and 24 123 (91.2%) White individuals. Participants were scheduled to undergo 3 screenings during the course of the trial; the present study included 75 126 LDCT screening examinations performed for 26 455 participants. A SIF was reported for 8954 (33.8%) of 26 455 participants who were screened with LDCT. Of screening tests with a SIF detected, 12 228 (89.1%) had a SIF considered reportable to the RC, with a higher proportion of reportable SIFs among those with a positive screen result for lung cancer (7632 [94.1%]) compared with those with a negative screen result (4596 [81.8%]). The most common SIFs reported included emphysema (8677 [43.0%] of 20 156 SIFs reported), coronary artery calcium (2432 [12.1%]), and masses or suspicious lesions (1493 [7.4%]). Masses included kidney (647 [3.2%]), liver (420 [2.1%]), adrenal (265 [1.3%]), and breast (161 [0.8%]) abnormalities. Classification was based on free-text comments; 2205 of 13 299 comments (16.6%) could not be classified. The hierarchical reporting of final diagnosis in NLST may have been associated with an overestimate of severe emphysema in participants with a positive screen result for lung cancer.

Conclusions and Relevance

This case series study found that SIFs were commonly reported in the LDCT arm of the National Lung Screening Trial, and most of these SIFs were considered reportable to the RC and likely to require follow-up. Future screening trials should standardize SIF reporting.

Prevalence and clinical characteristics of non-malignant CT detected incidental findings in the SUMMIT lung cancer screening cohort

BACKGROUND

Pulmonary and extrapulmonary incidental findings are frequently identified on CT scans performed for lung cancer screening. Uncertainty regarding their clinical significance and how and when such findings should be reported back to clinicians and participants persists. We examined the prevalence of non-malignant incidental findings within a lung cancer screening cohort and investigated the morbidity and relevant risk factors associated with incidental findings. We quantified the primary and secondary care referrals generated by our protocol.

METHODS

The SUMMIT study (NCT03934866) is a prospective observational cohort study to examine the performance of delivering a low-dose CT (LDCT) screening service to a high-risk population. Spirometry, blood pressure, height/weight and respiratory history were assessed as part of a Lung Health Check. Individuals at high risk of lung cancer were offered an LDCT and returned for two further annual visits. This analysis is a prospective evaluation of the standardised reporting and management protocol for incidental findings developed for the study on the baseline LDCT.

RESULTS

In 11 115 participants included in this analysis, the most common incidental findings were coronary artery calcification (64.2%) and emphysema (33.4%). From our protocolised management approach, the number of participants requiring review for clinically relevant findings in primary care was 1 in 20, and the number potentially requiring review in secondary care was 1 in 25.

CONCLUSIONS

Incidental findings are common in lung cancer screening and can be associated with reported symptoms and comorbidities. A standardised reporting protocol allows systematic assessment and standardises onward management.

A Quick Reference Guide for Incidental Findings on Lung Cancer Screening CT Examinations

PURPOSE

The US Preventive Services Task Force has recommended lung cancer screening (LCS) with low-dose CT (LDCT) in high-risk individuals since 2013. Because LDCT encompasses the lower neck, chest, and upper abdomen, many incidental findings (IFs) are detected. The authors created a quick reference guide to describe common IFs in LCS to assist LCS program navigators and ordering providers in managing the care continuum in LCS.

METHODS

The ACR IF white papers were reviewed for findings on LDCT that were age appropriate for LCS. A draft guide was created on the basis of recommendations in the IF white papers, the medical literature, and input from subspecialty content experts. The draft was piloted with LCS program navigators recruited through contacts by the ACR LCS Steering Committee. The navigators completed a survey on overall usefulness, clarity, adequacy of content, and user experience with the guide.

RESULTS

Seven anatomic regions including 15 discrete organs with 45 management recommendations were identified as relevant to the age of individuals eligible for LCS. The draft was piloted by 49 LCS program navigators from 32 facilities. The guide was rated as useful and clear by 95% of users. No unexpected or adverse experiences were reported in using the guide. On the basis of feedback, relevant sections were reviewed and edited.

CONCLUSIONS

The ACR Lung Cancer Screening CT Incidental Findings Quick Reference Guide outlines the common IFs in LCS and can serve as an easy-to-use resource for ordering providers and LCS program navigators to help guide management.

Effect of Incidental Findings Information on Lung Cancer Screening Intent: a Randomized Controlled Trial

BACKGROUND

The Centers for Medicare & Medicaid Services requires decision aid use for lung cancer screening (LCS) shared decision-making. However, it does not require information about incidental findings, a potential harm of screening.

OBJECTIVE

To assess the effect of incidental findings information in an LCS decision aid on screening intent as well as knowledge and valuing of screening benefits and harms.

DESIGN

Randomized controlled trial conducted online between July 16, 2020, and August 22, 2020.

PARTICIPANTS

Adults 55-80 years, eligible for LCS.

INTERVENTION

LCS video decision aid including information on incidental findings or a control video decision aid.

MAIN MEASURES

Intent to undergo LCS; knowledge regarding the benefit and harms of LCS using six knowledge questions; and valuing of six benefits and harms using rating (1-5 scale, 5 most important) and ranking (ranked 1-6) exercises.

KEY RESULTS

Of 427 eligible individuals approached, 348 (83.1%) completed the study (173 intervention, 175 control). Mean age was 64.5 years, 48.6% were male, 73.0% white, 76.3% with less than a college degree, and 64.1% with income < $50,000. There was no difference between the intervention and controls in percentage intending to pursue screening (70/173, 40.5% vs 73/175, 41.7%, diff 1.2%, 95% CI - 9.1 to 11.5%, p = 0.81). Intervention participants had a higher percentage of correct answers for the incidental findings knowledge than controls (164/173, 94.8% vs 129/175, 73.7%, 95% CI - 28.4 to - 13.8%, p < 0.01). Incidental findings had the fifth highest mean importance rating (4.0 ± 1.1) and the third highest mean ranking (3.6 ± 1.5). There was no difference in mean rating or ranking of incidental findings between intervention and control groups (rating 4.0 vs 3.9, diff 0.1, 95% CI - 0.2, 0.3, p = 0.51; ranking 3.6 vs 3.6, diff 0.02, 95% CI - 0.3, 0.3, p = 0.89).

CONCLUSIONS

Incidental findings information in a LCS decision aid did not affect LCS intent, but it resulted in more informed individuals regarding these findings. In formulating screening preferences, incidental findings were less important than other benefits and harms.

TRIAL REGISTRATION

ClinicalTrials.gov identifier: NCT04432753.

Lung Cancer Screening in a Safety-Net Hospital: Rare Harms Inform Decision Making

BACKGROUND

Lung cancer screening (LCS) with low-dose computed tomography (LDCT) decreases lung cancer mortality; however, screening benefits and harms are poorly described in minority populations. Our purpose is to report benefits and harms of LCS implemented in a safety-net institution. Because harms are rare, there is a paucity of clinical experience guiding shared decision making (SDM) with diverse populations.

METHODS

We conducted a prospective, observational study of patients undergoing LCS between September 2014 and March 2019 with 2-year follow-up. LDCT results, lung cancer diagnosis, stage, treatment, false-positive results, false-negative procedure from a false-positive result, complication from procedures, and death were recorded. Patient cases highlighting the challenges of delivering LCS to an underserved population were evaluated in the context of current evidence.

RESULTS

Among the 995 patients who underwent screening, 54.9% were African American, with 2.9% receiving a cancer diagnosis, a false-positive rate of 9.4% and a 0.7% rate of procedures resulting from a false-positive result. Five patient cases highlight challenges, namely (1) false-positive result resulting in operation, (2) false-negative result, (3) incidental finding, (4) delay in diagnosis, and (5) death from cause other than lung cancer.

CONCLUSIONS

LCS of a predominantly African American population with 2-year follow-up demonstrates early detection and treatment of lung cancer with few harms. Although rare, harms must be clearly described with population-specific evidence. We report clinical perspective of rare harms that can provide guidance to providers and patients.

Impact of low-dose computed tomography (LDCT) screening on lung cancer-related mortality

BACKGROUND

Lung cancer is the most common cause of cancer-related death in the world, however lung cancer screening has not been implemented in most countries at a population level. A previous Cochrane Review found limited evidence for the effectiveness of lung cancer screening with chest radiography (CXR) or sputum cytology in reducing lung cancer-related mortality, however there has been increasing evidence supporting screening with low-dose computed tomography (LDCT).  OBJECTIVES: To determine whether screening for lung cancer using LDCT of the chest reduces lung cancer-related mortality and to evaluate the possible harms of LDCT screening.

SEARCH METHODS

We performed the search in collaboration with the Information Specialist of the Cochrane Lung Cancer Group and included the Cochrane Lung Cancer Group Trial Register, Cochrane Central Register of Controlled Trials (CENTRAL, the Cochrane Library, current issue), MEDLINE (accessed via PubMed) and Embase in our search. We also searched the clinical trial registries to identify unpublished and ongoing trials. We did not impose any restriction on language of publication. The search was performed up to 31 July 2021.  SELECTION CRITERIA: Randomised controlled trials (RCTs) of lung cancer screening using LDCT and reporting mortality or harm outcomes.  DATA COLLECTION AND ANALYSIS: Two review authors were involved in independently assessing trials for eligibility, extraction of trial data and characteristics, and assessing risk of bias of the included trials using the Cochrane RoB 1 tool. We assessed the certainty of evidence using GRADE. Primary outcomes were lung cancer-related mortality and harms of screening. We performed a meta-analysis, where appropriate, for all outcomes using a random-effects model. We only included trials in the analysis of mortality outcomes if they had at least 5 years of follow-up. We reported risk ratios (RRs) and hazard ratios (HRs), with 95% confidence intervals (CIs) and used the I2 statistic to investigate heterogeneity.  MAIN RESULTS: We included 11 trials in this review with a total of 94,445 participants. Trials were conducted in Europe and the USA in people aged 40 years or older, with most trials having an entry requirement of ≥ 20 pack-year smoking history (e.g. 1 pack of cigarettes/day for 20 years or 2 packs/day for 10 years etc.). One trial included male participants only. Eight trials were phase three RCTs, with two feasibility RCTs and one pilot RCT. Seven of the included trials had no screening as a comparison, and four trials had CXR screening as a comparator. Screening frequency included annual, biennial and incrementing intervals. The duration of screening ranged from 1 year to 10 years. Mortality follow-up was from 5 years to approximately 12 years.  None of the included trials were at low risk of bias across all domains. The certainty of evidence was moderate to low across different outcomes, as assessed by GRADE. In the meta-analysis of trials assessing lung cancer-related mortality, we included eight trials (91,122 participants), and there was a reduction in mortality of 21% with LDCT screening compared to control groups of no screening or CXR screening (RR 0.79, 95% CI 0.72 to 0.87; 8 trials, 91,122 participants; moderate-certainty evidence). There were probably no differences in subgroups for analyses by control type, sex, geographical region, and nodule management algorithm. Females appeared to have a larger lung cancer-related mortality benefit compared to males with LDCT screening. There was also a reduction in all-cause mortality (including lung cancer-related) of 5% (RR 0.95, 95% CI 0.91 to 0.99; 8 trials, 91,107 participants; moderate-certainty evidence).  Invasive tests occurred more frequently in the LDCT group (RR 2.60, 95% CI 2.41 to 2.80; 3 trials, 60,003 participants; moderate-certainty evidence). However, analysis of 60-day postoperative mortality was not significant between groups (RR 0.68, 95% CI 0.24 to 1.94; 2 trials, 409 participants; moderate-certainty evidence).  False-positive results and recall rates were higher with LDCT screening compared to screening with CXR, however there was low-certainty evidence in the meta-analyses due to heterogeneity and risk of bias concerns. Estimated overdiagnosis with LDCT screening was 18%, however the 95% CI was 0 to 36% (risk difference (RD) 0.18, 95% CI -0.00 to 0.36; 5 trials, 28,656 participants; low-certainty evidence). Four trials compared different aspects of health-related quality of life (HRQoL) using various measures. Anxiety was pooled from three trials, with participants in LDCT screening reporting lower anxiety scores than in the control group (standardised mean difference (SMD) -0.43, 95% CI -0.59 to -0.27; 3 trials, 8153 participants; low-certainty evidence). There were insufficient data to comment on the impact of LDCT screening on smoking behaviour.  AUTHORS' CONCLUSIONS: The current evidence supports a reduction in lung cancer-related mortality with the use of LDCT for lung cancer screening in high-risk populations (those over the age of 40 with a significant smoking exposure). However, there are limited data on harms and further trials are required to determine participant selection and optimal frequency and duration of screening, with potential for significant overdiagnosis of lung cancer. Trials are ongoing for lung cancer screening in non-smokers.

Radiological Screening Methods in Deceased Organ Donation: An Overview of Guidelines Worldwide

Organ transplantation is performed worldwide, but policies regarding donor imaging are not uniform. An overview of the policies in different regions is missing. This study aims to investigate the various protocols worldwide on imaging in deceased organ donation. An online survey was created to determine the current policies. Competent authorities were approached to fill out the survey based on their current protocols. In total 32 of the 48 countries approached filled out the questionnaire (response rate 67%). In 16% of the countries no abdominal imaging is required prior to procurement. In 50%, abdominal ultrasound (US) is performed to screen the abdomen and in 19% an enhanced abdominal Computed Tomography (CT). In 15% of the countries both an unenhanced abdominal CT scan and abdominal US are performed. In 38% of the countries a chest radiographic (CXR) is performed to screen the thorax, in 28% only a chest CT, and in 34% both are performed. Policies regarding radiologic screening in deceased organ donors show a great variation between different countries. Consensus on which imaging method should be applied is missing. A uniform approach will contribute to quality and safety, justifying (inter)national exchange of organs.

Low-dose CT for lung cancer screening: position paper from the Italian college of thoracic radiology

Smoking is the main risk factor for lung cancer (LC), which is the leading cause of cancer-related death worldwide. Independent randomized controlled trials, governmental and inter-governmental task forces, and meta-analyses established that LC screening (LCS) with chest low dose computed tomography (LDCT) decreases the mortality of LC in smokers and former smokers, compared to no-screening, especially in women. Accordingly, several Italian initiatives are offering LCS by LDCT and smoking cessation to about 10,000 high-risk subjects, supported by Private or Public Health Institutions, envisaging a possible population-based screening program. Because LDCT is the backbone of LCS, Italian radiologists with LCS expertise are presenting this position paper that encompasses recommendations for LDCT scan protocol and its reading. Moreover, fundamentals for classification of lung nodules and other findings at LDCT test are detailed along with international guidelines, from the European Society of Thoracic Imaging, the British Thoracic Society, and the American College of Radiology, for their reporting and management in LCS. The Italian College of Thoracic Radiologists produced this document to provide the basics for radiologists who plan to set up or to be involved in LCS, thus fostering homogenous evidence-based approach to the LDCT test over the Italian territory and warrant comparison and analyses throughout National and International practices.

European lung cancer screening: valuable trial evidence for optimal practice implementation

Lung cancer screening (LCS) by low-dose computed tomography is a strategy for secondary prevention of lung cancer. In the last two decades, LCS trials showed several options to practice secondary prevention in association with primary prevention, however, the translation from trial to practice is everything but simple. In 2020, the European Society of Radiology and European Respiratory Society published their joint statement paper on LCS. This commentary aims to provide the readership with detailed description about hurdles and potential solutions that could be encountered in the practice of LCS.

Earlier diagnosis of lung cancer

The purpose of this article is to review options for more rapid diagnosis of lung cancer at an earlier stage, thereby improving survival. These options include screening, allowing general practitioners to refer patients directly to low-dose computed tomography scan instead of a chest X-ray and the abolition of the "visitation filter", i.e. hospital doctors' ability to reject referrals from general practitioners without prior discussion with the referring doctor.

Incidence of Head and Neck Cancer With Lung Cancer Screening: Secondary Analysis of a Randomized Controlled Trial

OBJECTIVES/HYPOTHESIS

To evaluate the incidence of head and neck cancers (HNC) in high-risk current and/or former smokers with screening low-dose computed tomography (LDCT) chest versus chest x-ray (CXR).

STUDY DESIGN

Second analysis of randomized clinical trial.

METHODS

We performed a secondary analysis examining the incidence of HNC in the National Lung Screening Trial. This was a randomized trial comparing LDCT versus CXR screening for lung cancer detection in high-risk individuals (30 pack-year smokers who currently smoke or quit within the last 15 years, aged 55-74). We compared the incidence of HNC in participants screened with LDCT versus CXR. We performed subgroup analyses in participants with mucosal HNC (oral cavity, oropharynx, larynx, hypopharynx, nasal/sinus cavity, or nasopharynx) or nonmucosal HNC (thyroid or salivary gland) and examined survival in the two screening arms.

RESULTS

This trial enrolled 53,452 participants with a median follow-up of 6.2 years after randomization. The incidence of HNC was 111.8 cases per 100,000 person-years in the LDCT group versus 87.1 cases per 100,000 person-years in the CXR group (rate ratio 1.30, 95% confidence interval [CI] 1.05-1.61). There were 11.7 deaths from HNC per 100,000 person-years in the LDCT group and 12.9 deaths per 100,000 person-years in the CXR group (hazard ratio 0.80, 95% CI 0.42-1.52).

CONCLUSIONS

Participants screened with LDCT had a modestly higher incidence of HNC. As uptake and adherence of lung cancer screening guidelines improve, clinicians should recognize that incidental findings from screening may lead to increased detection of HNC.

LEVEL OF EVIDENCE

3 Laryngoscope, 2022.

Mediastinal Lymphadenopathy in the National Lung Screening Trial (NLST) Is Associated with Interval Lung Cancer

Background There are currently no evidence-based guidelines for the management of enlarged mediastinal lymph nodes found on lung cancer screening (LCS) CT scans. Purpose To assess the frequency and clinical significance of enlarged mediastinal lymph nodes on the initial LCS CT scans in National Lung Screening Trial (NLST) participants. Materials and Methods A retrospective review of the NLST database identified all CT trial participants with at least one enlarged (≥1.0 cm) mediastinal lymph node identified by site readers on initial CT scans. Each study was reviewed independently by two thoracic radiologists to measure the two largest nodes and to record morphologic characteristics. Scans with extensively calcified mediastinal lymph nodes or nodes measuring less than 1 cm were excluded. Frequency and time to lung cancer diagnosis, lung cancer stage, and histologic findings were compared between NLST participants with and without lymphadenopathy. Results Of the 26 722 NLST participants, 422 (1.6%) had enlarged noncalcified mediastinal lymph nodes on the initial LCS CT scan. Mediastinal lymphadenopathy was associated with an increase in lung cancer cases (72 of 422 participants [17.1%; 95% CI: 13.6, 21.0] vs 1017 of 26 300 [3.9%; 95% CI: 3.6, 4.1]; P < .001), earlier diagnosis (restricted mean survival time ± standard error, 2285 days ± 44 vs 2611 days ± 2; P < .001), the presence of lung nodules (P < .001), advanced stage at presentation (22 of 72 participants [31%] with cancer at stage IIIA vs 410 of 1017 [40.3%] at stage IA; P < .001), and increased mortality (P < .001). The majority of participants with lung cancers in the LCS group with mediastinal lymphadenopathy were detected at initial LCS CT (50 of 422 participants [11.8%; 95% CI: 8.9, 15.3] vs T1-T7, 22 of 422 [5.3%; 95% CI: 3.3, 7.8]; P < .001). There was no association between mediastinal lymphadenopathy and lung cancer histologic findings, CT appearance, or location of lung nodules (P > .05 based on unadjusted pairwise association analyses). Conclusion Noncalcified mediastinal lymphadenopathy in the low-dose lung cancer screening study sample was associated with an increase in lung cancer, an earlier diagnosis, more advanced-stage disease, and increased mortality. More aggressive treatment of these patients appears warranted. © RSNA, 2021 Online supplemental material is available for this article. See also the editorials by McLoud and by Mascalchi and Zompatori in this issue.

The BUILT study: a single-center 5-year experience of Lung Cancer screening in Taiwan

Background: There are no uniform guidelines on low-dose computed tomography (LDCT) follow-up in lung cancer screening. Few studies have analyzed the incidental abnormalities and role of tumor markers in lung cancer screening. The purpose of this study was to investigate the diagnostic performance of LDCT, optimal follow-up duration, incidental findings, and role of tumor markers in diagnosing lung cancer. Methods: We retrospectively analyzed subjects who underwent their first LDCT in Taipei Tzu Chi Hospital between September 1, 2015, and August 31, 2016. All chest CT scans until August 31, 2020, were recorded. A non-calcified nodule with a diameter ≥2 mm on LDCT was defined as a positive result. We extracted the data, including possible risk factors of lung cancer and follow-up outcomes. Results: A total of 1502 subjects were recruited. Of the 38 subjects who underwent biopsy, 31 had confirmed lung cancer. Lung cancer in all patients was diagnosed within 4 years. Univariate logistic regression analysis revealed that a family history of lung cancer in first-degree relatives and abnormal serum carcinoembryonic antigen (CEA) levels were the significant risk factors for lung cancer. A cumulative lung cancer incidence of 54.7 patients per 1000 person-years was determined solely via radiological follow-up. In total, 271 (18%) subjects exhibited incidental findings on baseline LDCT. Conclusion: The overall lung cancer detection rate in this study was 2.1% in the 5-year study period. A family history of lung cancer and abnormal serum CEA levels are important risk factors for lung cancer. A minimum of 4-year follow-up is required to track suspicious nodules. A purely radiological follow-up detects a high incidence of lung cancer.

Evaluation of the Effectiveness of Artificial Intelligence Chest CT Lung Nodule Detection Based on Deep Learning

Lung cancer is one of the most malignant tumors. If it can be detected early and treated actively, it can effectively improve a patient's survival rate. Therefore, early diagnosis of lung cancer is very important. Early-stage lung cancer usually appears as a solitary lung nodule on medical imaging. It usually appears as a round or nearly round dense shadow in the chest radiograph. It is difficult to distinguish lung nodules and lung soft tissues with the naked eye. Therefore, this article proposes a deep learning-based artificial intelligence chest CT lung nodule detection performance evaluation study, aiming to evaluate the value of chest CT imaging technology in the detection of noncalcified nodules and provide help for the detection and treatment of lung cancer. In this article, the Lung Medical Imaging Database Consortium (LIDC) was selected to obtain 536 usable cases based on inclusion criteria; 80 cases were selected for examination, artificial intelligence software, radiologists, and thoracic imaging specialists. Using 80 pulmonary nodules detection in each case, the pathological type of pulmonary nodules, nonlime tuberculous test results, detection sensitivity, false negative rate, false positive rate, and CT findings were individually analyzed, and the detection efficiency software of artificial intelligence was evaluated. Experiments have proved that the sensitivity of artificial intelligence software to detect noncalcified nodules in the pleural, peripheral, central, and hilar areas is higher than that of radiologists, indicating that the method proposed in this article has achieved good detection results. It has a better nodule detection sensitivity than a radiologist, reducing the complexity of the detection process.

Clinical application of mask region-based convolutional neural network for the automatic detection and segmentation of abnormal liver density based on hepatocellular carcinoma computed tomography datasets

The aim of the study was to use a previously proposed mask region–based convolutional neural network (Mask R-CNN) for automatic abnormal liver density detection and segmentation based on hepatocellular carcinoma (HCC) computed tomography (CT) datasets from a radiological perspective. Training and testing datasets were acquired retrospectively from two hospitals of Taiwan. The training dataset contained 10,130 images of liver tumor densities of 11,258 regions of interest (ROIs). The positive testing dataset contained 1,833 images of liver tumor densities with 1,874 ROIs, and negative testing data comprised 20,283 images without abnormal densities in liver parenchyma. The Mask R-CNN was used to generate a medical model, and areas under the curve, true positive rates, false positive rates, and Dice coefficients were evaluated. For abnormal liver CT density detection, in each image, we identified the mean area under the curve, true positive rate, and false positive rate, which were 0.9490, 91.99%, and 13.68%, respectively. For segmentation ability, the highest mean Dice coefficient obtained was 0.8041. This study trained a Mask R-CNN on various HCC images to construct a medical model that serves as an auxiliary tool for alerting radiologists to abnormal CT density in liver scans; this model can simultaneously detect liver lesions and perform automatic instance segmentation.

Frequency and spectrum of incidental findings when using chest CT as a primary triage tool for COVID-19

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Of the 232 participants triaged with chest CT for COVID-19, 126 (54 %) showed one or more incidental findings (IF).

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53 Participants (23 %) showed a potentially significant IF.

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A potentially significant IF requires further diagnostic or clinical work up.

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The most common potentially significant IFs were coronary artery calcifications, suspicious breast- and pulmonary nodules.

Purpose

To determine the prevalence and spectrum of incidental findings (IFs) identified in patients undergoing chest CT as a primary triage tool for COVID-19.

Methods

In this study 232 patients were triaged in our COVID-19 Screening Unit by means of a chest CT (March 25–April 23, 2020). Original radiology reports were evaluated retrospectively for the description of IFs, which were defined as any finding in the report not related to the purpose of the scan. Documented IFs were categorized according to clinical relevance into minor and potentially significant IFs and according to anatomical location into pulmonary, mediastinal, cardiovascular, breast, upper abdominal and skeletal categories. IFs were reported as frequencies and percentages; descriptive statistics were used.

Results

In total 197 IFs were detected in 126 patients (54 % of the participants). Patients with IFs were on average older (54.0 years old, SD 16.6) than patients without IFs (44.8 years old, SD 14.6, P < 0.05). In total 60 potentially significant IFs were detected in 53 patients (23 % of the participants). Most often reported were coronary artery calcifications (n = 23, 38 % of total potentially significant IFs/ 10 % of the total study population), suspicious breast nodules (n = 7, 12 % of total potentially significant IFs/ 3% of the total study population) and pulmonary nodules (n = 7, 12 % of total potentially significant IFs/ 3% of the total study population).

Conclusion

A considerable number of IFs were detected by using chest CT as a primary triage tool for COVID-19, of which a substantial percentage (23 %) is potentially clinically relevant.

[Adrenal imaging: anatomy and pathology (literature review)]

This literature review focuses on the normal adrenal gland anatomy and typical imaging features necessary to evaluate benign and malignant lesions. In particular, adenoma, pheochromocytoma, metastases and adrenocortical carcinoma were discussed as some of the most common lesions. For this purpose, a review of relevant local and international literature sources up to January 2021 was conducted.In many cases, adrenal incidentalomas have distinctive features allowing characterization using noninvasive methods. It is possible to suspect a malignant nature and promptly refer the patient for the necessary invasive examinations in some cases. -Computed tomography, especially with intravenous contrast enhancement, is the primary imaging modality because it enables differential diagnosis. Magnetic resonance tomography remains a sensitive method in lesion detection and follow-up but is not very specific for determining the malignant potential. Positron emission computed tomography also remains an additional method and is used mainly for differential diagnosis of malignant tumors, detecting metastases and recurrences after surgical treatment. Ultrasound has a limited role but is nevertheless of great importance in the pediatric population, especially newborns. Promising techniques such as radiomics and dual-energy CT can expand imaging capabilities and improve diagnostic accuracy.Because adrenal lesions are often incidentally detected by imaging performed for other reasons, it is vital to interpret such findings correctly. This review should give the reader a broad overview of how different imaging modalities can evaluate adrenal pathology and guide radiologists and clinicians.

Ongoing challenges in implementation of lung cancer screening

Lung cancer is the leading cause of cancer deaths in Europe and around the world. Although available therapies have undergone considerable development in the past decades, the five-year survival rate for lung cancer remains low. This sobering outlook results mainly from the advanced stages of cancer most patients are diagnosed with. As the population at risk is relatively well defined and early stage disease is potentially curable, lung cancer outcomes may be improved by screening. Several studies already show that lung cancer screening (LCS) with low-dose computed tomography (LDCT) reduces lung cancer mortality. However, for a successful implementation of LCS programmes, several challenges have to be overcome: selection of high-risk individuals, standardization of nodule classification and measurement, specific training of radiologists, optimization of screening intervals and screening duration, handling of ancillary findings are some of the major points which should be addressed. Last but not least, the psychological impact of screening on screened individuals and the impact of potential false positive findings should not be neglected. The aim of this review is to discuss the different challenges of implementing LCS programmes and to give some hints on how to overcome them. Finally, we will also discuss the psychological impact of screening on quality of life and the importance of smoking cessation.

Screening for Lung Cancer With Low-Dose Computed Tomography: Updated Evidence Report and Systematic Review for the US Preventive Services Task Force

IMPORTANCE

Lung cancer is the leading cause of cancer-related death in the US.

OBJECTIVE

To review the evidence on screening for lung cancer with low-dose computed tomography (LDCT) to inform the US Preventive Services Task Force (USPSTF).

DATA SOURCES

MEDLINE, Cochrane Library, and trial registries through May 2019; references; experts; and literature surveillance through November 20, 2020.

STUDY SELECTION

English-language studies of screening with LDCT, accuracy of LDCT, risk prediction models, or treatment for early-stage lung cancer.

DATA EXTRACTION AND SYNTHESIS

Dual review of abstracts, full-text articles, and study quality; qualitative synthesis of findings. Data were not pooled because of heterogeneity of populations and screening protocols.

MAIN OUTCOMES AND MEASURES

Lung cancer incidence, lung cancer mortality, all-cause mortality, test accuracy, and harms.

RESULTS

This review included 223 publications. Seven randomized clinical trials (RCTs) (N = 86 486) evaluated lung cancer screening with LDCT; the National Lung Screening Trial (NLST, N = 53 454) and Nederlands-Leuvens Longkanker Screenings Onderzoek (NELSON, N = 15 792) were the largest RCTs. Participants were more likely to benefit than the US screening-eligible population (eg, based on life expectancy). The NLST found a reduction in lung cancer mortality (incidence rate ratio [IRR], 0.85 [95% CI, 0.75-0.96]; number needed to screen [NNS] to prevent 1 lung cancer death, 323 over 6.5 years of follow-up) with 3 rounds of annual LDCT screening compared with chest radiograph for high-risk current and former smokers aged 55 to 74 years. NELSON found a reduction in lung cancer mortality (IRR, 0.75 [95% CI, 0.61-0.90]; NNS to prevent 1 lung cancer death of 130 over 10 years of follow-up) with 4 rounds of LDCT screening with increasing intervals compared with no screening for high-risk current and former smokers aged 50 to 74 years. Harms of screening included radiation-induced cancer, false-positive results leading to unnecessary tests and invasive procedures, overdiagnosis, incidental findings, and increases in distress. For every 1000 persons screened in the NLST, false-positive results led to 17 invasive procedures (number needed to harm, 59) and fewer than 1 person having a major complication. Overdiagnosis estimates varied greatly (0%-67% chance that a lung cancer was overdiagnosed). Incidental findings were common, and estimates varied widely (4.4%-40.7% of persons screened).

CONCLUSIONS AND RELEVANCE

Screening high-risk persons with LDCT can reduce lung cancer mortality but also causes false-positive results leading to unnecessary tests and invasive procedures, overdiagnosis, incidental findings, increases in distress, and, rarely, radiation-induced cancers. Most studies reviewed did not use current nodule evaluation protocols, which might reduce false-positive results and invasive procedures for false-positive results.

Krist AH, Davidson KW, Mangione CM, Barry MJ, Cabana M, Caughey AB, Davis EM, Donahue KE, Doubeni CA, Kubik M, Landefeld CS, Li L, Ogedegbe G, Owens DK, Pbert L, Silverstein M, Stevermer J, Tseng CW, Wong JB. Screening for Lung Cancer: US Preventive Services Task Force Recommendation Statement

IMPORTANCE

Lung cancer is the second most common cancer and the leading cause of cancer death in the US. In 2020, an estimated 228 820 persons were diagnosed with lung cancer, and 135 720 persons died of the disease. The most important risk factor for lung cancer is smoking. Increasing age is also a risk factor for lung cancer. Lung cancer has a generally poor prognosis, with an overall 5-year survival rate of 20.5%. However, early-stage lung cancer has a better prognosis and is more amenable to treatment.

OBJECTIVE

To update its 2013 recommendation, the US Preventive Services Task Force (USPSTF) commissioned a systematic review on the accuracy of screening for lung cancer with low-dose computed tomography (LDCT) and on the benefits and harms of screening for lung cancer and commissioned a collaborative modeling study to provide information about the optimum age at which to begin and end screening, the optimal screening interval, and the relative benefits and harms of different screening strategies compared with modified versions of multivariate risk prediction models.

POPULATION

This recommendation statement applies to adults aged 50 to 80 years who have a 20 pack-year smoking history and currently smoke or have quit within the past 15 years.

EVIDENCE ASSESSMENT

The USPSTF concludes with moderate certainty that annual screening for lung cancer with LDCT has a moderate net benefit in persons at high risk of lung cancer based on age, total cumulative exposure to tobacco smoke, and years since quitting smoking.

RECOMMENDATION

The USPSTF recommends annual screening for lung cancer with LDCT in adults aged 50 to 80 years who have a 20 pack-year smoking history and currently smoke or have quit within the past 15 years. Screening should be discontinued once a person has not smoked for 15 years or develops a health problem that substantially limits life expectancy or the ability or willingness to have curative lung surgery. (B recommendation) This recommendation replaces the 2013 USPSTF statement that recommended annual screening for lung cancer with LDCT in adults aged 55 to 80 years who have a 30 pack-year smoking history and currently smoke or have quit within the past 15 years.

Lung-RADS Version 1.1: Challenges and a Look Ahead, From the AJR Special Series on Radiology Reporting and Data Systems

In 2014, the American College of Radiology (ACR) created Lung-RADS 1.0. The system was updated to Lung-RADS 1.1 in 2019, and further updates are anticipated as additional data become available. Lung-RADS provides a common lexicon and standardized nodule follow-up management paradigm for use when reporting lung cancer screening (LCS) low-dose CT (LDCT) chest examinations and serves as a quality assurance and outcome monitoring tool. The use of Lung-RADS is intended to improve LCS performance and lead to better patient outcomes. To date, the ACR's Lung Cancer Screening Registry is the only LCS registry approved by the Centers for Medicare & Medicaid Services and requires the use of Lung-RADS categories for reimbursement. Numerous challenges have emerged regarding the use of Lung-RADS in clinical practice, including the timing of return to LCS after planned follow-up diagnostic evaluation; potential substitution of interval diagnostic CT for future LDCT; role of volumetric analysis in assessing nodule size; assessment of nodule growth; assessment of cavitary, subpleural, and category 4X nodules; and variability in reporting of the S modifier. This article highlights the major updates between versions 1.0 and 1.1 of Lung-RADS, describes the system's ongoing challenges, and summarizes current evidence and recommendations.

[Progress of Lung Cancer Screening with Low Dose Helical Computed Tomography]

Lung cancer which represents characteristics of a heavy disease burden, a large proportion of advanced lung cancer and a low five-year survival rate is a threat to human health. It is essential to implement population-based lung cancer screening to improve early detection and early treatment. The National Lung Screening Trial (NLST) demonstrated that screening with low dose helical computed tomography (LDCT) may decrease lung cancer mortality, which brings hope for the early diagnosis and treatment of lung cancer. In recent years, great progresses have been made on research of lung cancer screening with LDCT. However, whether LDCT could be applied to large population-based lung cancer screening projects is still under debate. In this paper, we review the recent progresses on history of lung cancer screening with LDCT, selection of high-risk individuals, management of pulmonary nodules, performance of screening, acceptance of LDCT and cost-effectiveness.
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Organized Lung Cancer Screening Pilot: Informing a Province-Wide Program in Ontario, Canada

BACKGROUND

Lung cancer is the leading cause of cancer deaths in Ontario. The National Lung Screening Trial demonstrated that screening with low-dose computed tomography (LDCT) reduces lung cancer mortality.

METHODS

In June 2017, Ontario Health (Cancer Care Ontario) initiated a pilot for lung cancer screening to inform implementation of a province-wide initiative. The screening pathway includes targeted recruitment strategies, the Tammemägi risk prediction model (PLCOm2012) to determine eligibility, opt-out smoking cessation services for all current smokers, use of the Lung-RADS scoring system to guide abnormal results management, and screening navigators providing end-to-end support. Referral criteria include being 55 years of age to 74 years of age and a current or former daily cigarette smoker for greater than or equal to 20 years, while the screening eligibility criterion is a PLCOm2012 risk greater than or equal to 2% in 6 years. Selected results of the interim pilot evaluation are presented. Four hospitals contributed data in the first year of the pilot.

RESULTS

During 2017 to 2018, 4205 Ontarians were recruited, 3234 risk assessments were conducted, and 2151 (66.5%) individuals were eligible for screening. Baseline LDCT scans were performed in 1624 (50.2%) individuals. Diagnostic evaluation in 120 (7.4%) individuals identified 28 (1.7%) with lung cancer, and proportions of stage I to II and stage III to IV were 71% and 29%, respectively. Of those recruited, 1443 (34.3%) individuals were smokers and 1326 (91.9%) accepted smoking cessation services.

CONCLUSIONS

The pilot is the largest in Canada and aligns with International Agency for Research on Cancer standards for population-based, organized cancer screening. Recruitment of high-risk individuals, high rates of smoking cessation program acceptance, and detection of early-stage cancers are demonstrated.

Thyroid Incidentalomas: Practice Considerations for Radiologists in the Age of Incidental Findings

Radiologists very frequently encounter incidental findings related to the thyroid gland. Given increases in imaging use over the past several decades, thyroid incidentalomas are increasingly encountered in clinical practice, and it is important for radiologists to be aware of recent developments with respect to workup and diagnosis of incidental thyroid abnormalities. Recent reporting and management guidelines, such as those from the American College of Radiology and American Thyroid Association, are reviewed along with applicable evidence in the literature. Trending topics, such as artificial intelligence approaches to guide thyroid incidentaloma workup, are also discussed.

Low-Dose CT Screening for Lung Cancer: Evidence from 2 Decades of Study

Lung cancer remains the overwhelmingly greatest cause of cancer death in the United States, accounting for more annual deaths than breast, prostate, and colon cancer combined. Accumulated evidence since the mid to late 1990s, however, indicates that low-dose CT screening of high-risk patients enables detection of lung cancer at an early stage and can reduce the risk of dying from lung cancer. CT screening is now a recommended clinical service in the United States, subject to guidelines and reimbursement requirements intended to standardize practice and optimize the balance of benefits and risks. In this review, the evidence on the effectiveness of CT screening will be summarized and the current guidelines and standards will be described in the context of knowledge gained from lung cancer screening studies. In addition, an overview of the potential advances that may improve CT screening will be presented, and the need to better understand the performance in clinical practice outside of the research trial setting will be discussed. © RSNA, 2020.

Interstitial lung abnormalities in the Queensland Lung Cancer Screening Study: prevalence and progression over 2 years of surveillance

BACKGROUND

We report the prevalence and progression of incidentally detected interstitial lung abnormalities (ILA) in the Queensland Lung Cancer Screening Study cohort.

METHODS

About 256 volunteers aged 60-74, with ≥30 pack years smoking history and forced expiratory volume in 1 s (FEV1) ≥50% predicted underwent low-dose computed tomography (CT) chest screening. Electronic search of baseline (T0) and 2-year follow-up (T2) CT reports identified candidate cases using Fleischner Society interstitial terminology. Candidate CT were reviewed in a randomised order by two experienced radiologists and a senior respiratory medicine trainee blinded to the existing reports. Scans were evaluated for the presence and extent of ILA using an in-house score, and graded for progression.

RESULTS

ILA were detected in 20/256 baseline cases (7.8%) with no incident cases detected at T2 surveillance imaging. Of these 20 cases, 9 (45%) had reticulation, 18 (90%) had ground glass change, 1 had traction bronchiectasis and 1 had randomly distributed nodularity. Seven cases with ground glass changes also had areas of reticulation, and only two had reticulation alone. All ILA were graded as minor except for traction bronchiectasis, which was moderate. Only one case progressed on T2 imaging. ILA were associated with the presence of auscultatory crackles (50% vs 11.6%, P = 0.001) and a lesser degree of emphysema (mean % volumetric emphysema 6.7% vs 9.8%, P = 0.009). No relationship was observed between baseline and serial lung function parameters.

CONCLUSION

ILA are frequent incidental findings in lung cancer screening. In the majority of cases these abnormalities do not appear to change significantly over a 2-year period of surveillance.

ESR/ERS statement paper on lung cancer screening

In Europe, lung cancer ranks third among the most common cancers, remaining the biggest killer. Since the publication of the first European Society of Radiology and European Respiratory Society joint white paper on lung cancer screening (LCS) in 2015, many new findings have been published and discussions have increased considerably. Thus, this updated expert opinion represents a narrative, non-systematic review of the evidence from LCS trials and description of the current practice of LCS as well as aspects that have not received adequate attention until now. Reaching out to the potential participants (persons at high risk), optimal communication and shared decision-making will be key starting points. Furthermore, standards for infrastructure, pathways and quality assurance are pivotal, including promoting tobacco cessation, benefits and harms, overdiagnosis, quality, minimum radiation exposure, definition of management of positive screen results and incidental findings linked to respective actions as well as cost-effectiveness. This requires a multidisciplinary team with experts from pulmonology and radiology as well as thoracic oncologists, thoracic surgeons, pathologists, family doctors, patient representatives and others. The ESR and ERS agree that Europe's health systems need to adapt to allow citizens to benefit from organised pathways, rather than unsupervised initiatives, to allow early diagnosis of lung cancer and reduce the mortality rate. Now is the time to set up and conduct demonstration programmes focusing, among other points, on methodology, standardisation, tobacco cessation, education on healthy lifestyle, cost-effectiveness and a central registry.

ESR/ERS statement paper on lung cancer screening

In Europe, lung cancer ranks third among the most common cancers, remaining the biggest killer. Since the publication of the first European Society of Radiology and European Respiratory Society joint white paper on lung cancer screening (LCS) in 2015, many new findings have been published and discussions have increased considerably. Thus, this updated expert opinion represents a narrative, non-systematic review of the evidence from LCS trials and description of the current practice of LCS as well as aspects that have not received adequate attention until now. Reaching out to the potential participants (persons at high risk), optimal communication and shared decision-making will be key starting points. Furthermore, standards for infrastructure, pathways and quality assurance are pivotal, including promoting tobacco cessation, benefits and harms, overdiagnosis, quality, minimum radiation exposure, definition of management of positive screen results and incidental findings linked to respective actions as well as cost-effectiveness. This requires a multidisciplinary team with experts from pulmonology and radiology as well as thoracic oncologists, thoracic surgeons, pathologists, family doctors, patient representatives and others. The ESR and ERS agree that Europe's health systems need to adapt to allow citizens to benefit from organised pathways, rather than unsupervised initiatives, to allow early diagnosis of lung cancer and reduce the mortality rate. Now is the time to set up and conduct demonstration programmes focusing, among other points, on methodology, standardisation, tobacco cessation, education on healthy lifestyle, cost-effectiveness and a central registry.Key Points• Pulmonologists and radiologists both have key roles in the set up of multidisciplinary LCS teams with experts from many other fields.• Pulmonologists identify people eligible for LCS, reach out to family doctors, share the decision-making process and promote tobacco cessation.• Radiologists ensure appropriate image quality, minimum dose and a standardised reading/reporting algorithm, together with a clear definition of a "positive screen".• Strict algorithms define the exact management of screen-detected nodules and incidental findings.• For LCS to be (cost-)effective, it has to target a population defined by risk prediction models.

Use of Imaging and Diagnostic Procedures After Low-Dose CT Screening for Lung Cancer

BACKGROUND

Clinical trials have demonstrated a mortality benefit from lung cancer screening by low-dose CT (LDCT) in current or past tobacco smokers who meet criteria. Potential harms of screening mostly relate to downstream evaluation of abnormal screens. Few data exist on the rates outside of clinical trials of imaging and diagnostic procedures following screening LDCT. We describe rates in the community setting of follow-up imaging and diagnostic procedures after screening LDCT.

METHODS

We used Clinformatics Data Mart national database to identify enrollees age 55 to 80 year who underwent screening LDCT from January 1, 2016, to December 31, 2016. We assessed rates of follow-up imaging (diagnostic chest CT scan, MRI, and PET) and follow-up procedures (bronchoscopy, percutaneous biopsy, thoracotomy, mediastinoscopy, and thoracoscopy) in the 12 months following LDCT for lung cancer screening. We also assessed these rates in an age-, sex-, and number of comorbidities-matched population that did not undergo LDCT to estimate rates unrelated to the screening LDCT. We then reported the adjusted rate of follow-up testing as the observed rate in the screening LDCT population minus the rate in the non-LDCT population.

RESULTS

Among 11,520 enrollees aged 55 to 80 years who underwent LDCT in 2016, the adjusted rates of follow up 12 months after LDCT examinations were low (17.7% for imaging and 3.1% for procedures). Among procedures, the adjusted rates were 2.0% for bronchoscopy, 1.3% for percutaneous biopsy, 0.9% for thoracoscopy, 0.2% for mediastinoscopy, and 0.4% for thoracotomy. Adjusted rates of follow-up procedures were higher in enrollees undergoing an initial screening LDCT (3.3%) than in those after a second screening examination (2.2%).

CONCLUSIONS

In general, imaging and rates of procedures after screening LDCT was low in this commercially insured population.