CT Screening For Lung Cancer Research Articles

Factors affecting patient adherence to lung cancer screening: A multisite analysis.

To identify factors associated with delayed adherence to follow-up in lung cancer screening. Utilizing a data warehouse and lung cancer screening registry, variables were collected from a referred sample of 3110 unique participants with follow-up CT during the study period (1 January 2016 to 17 October 2018). Adherence was defined as undergoing chest CT within 90 days and 30 days of the recommended time for follow-up and was determined using proportions and multiple variable logistic regression models across the American College of Radiology Lung Imaging Reporting and Data System (Lung-RADS®) categories. Of 1954 lung cancer screening participants (51.9% (1014/1954) males, 48.1% (940/1954) female; mean age 65.7 (range 45-87), smoking history median 40 pack-years, 60.2% and 44.5% did not follow-up within 30 and 90 days, respectively. Participants receiving Lung-RADS® category 1 or 2 presented later than those with Lung-RADS® category 3 at 90 days (coefficient -27.24, 95% CI -51.31, -3.16, p = 0.027). Participants with Lung-RADS® category 1 presented later than those with Lung-RADS® category 2 at both 90- and 30-days past due (OR 0.76 95% CI [0.59-0.97], p = 0.029 and OR 0.63 95% CI [0.48-0.83], p = 0.001, respectively). Adherence to follow-up was higher among participants receiving more suspicious Lung-RADS® results at index screening CT and among those who had undergone more non-lung cancer screening imaging examinations prior to index lung cancer screening CT. These observations may inform strategies aimed at prospectively identifying participants at risk for delayed or nonadherence to prevent potential morbidity and mortality from incident lung cancers.

Delivering low-dose CT screening for lung cancer: a pragmatic approach

Lung cancer kills an estimated 35 000 people in the UK every year. Despite the improvements in treating late-stage disease, lung cancer outcomes have changed little in the last 40...

Abstract 5887: Clonal heterogeneity and evolution of multifocal lung cancers revealed by whole exome sequencing to facilitate molecular diagnosis of multiple primary lung cancers

Abstract Background: Recent advances in CT screening of lung cancer has led to an increased incidence of detecting multifocal lung cancers (MFLCs). It has been suggested that the development of lung adenocarcinoma progresses from preinvasive atypical adenomatous hyperplasia (AAH) and adenocarcinoma in situ (AIS), to minimally invasive adenocarcinoma (MIA), and finally invasive lung adenocarcinoma (ADC). In patients with MFLCs, pulmonary nodules at different size and stage can be observed. Discrimination of synchronous multiple primary lung cancers (SMPLCs) from intrapulmonary metastases is challenging, which may influence the optimal approach for patient management. Method:Whole-exome sequencing (WES) was performed on 100 resected lung nodule samples (18 AAH, 15 AIS, 12 MIA, 55 ADC) from 33 patients with clinical diagnosed SMPLCs (3 samples per patient in average, ranging from 1 to 8 samples per patient). Result:In this cohort, 76% of patients (25/33) had at least one invasive ADC nodules while four patients had preinvasive (AAH/AIS) nodules only. Progressive evolution of lung tumors was marked by elevated chromosome instability (CIN) and tumor mutational burden (TMB). CIN was significantly higher in ADC lesions compared to other stage lesions. High frequencies of somatic copy number alterations (SCNAs) were identified in both arms of chr19 and the short arm of chr17 (17p) with a trend of progressively increase from AAH to ADC. Mutational signatures associated with age, APOBEC, BRAC and DNA mismatch repair (MMR) deficiency had the tendency to be enriched in later-stage nodules. 54.5% of the patients carried EGFR driver mutations, mainly L858R (89%), but the ratio of EGFR alterations displayed progressively increase from AAH (11%) to ADC (42%). Within the 29 patients with multiple nodules sampled, 10 cases displayed focal-specific EGFR-L858R, three of which had concurrent focal-specific EGFR-e19del. Five patients had EGFR-L858R detected in all the nodules. Pathway analysis revealed that dominant alterations along development of lung adenocarcinoma were centered around MAPK/ERK pathway, evolving from altered downstream genes, such as MAP2K1 and BRAF, in early stage to mutated upstream activator, such as EGFR, in later stage. Majority of MFLCs showed difference in clonal evolution and developmental stage, suggesting independent clonal origins. Multiple overlapping alterations were observed between intra-focal tumor lesions from the same or different lobes in 27.5% of patients (8/29), indicating intrapulmonary metastases. Conclusion: Evolution of lung tumors was associated with increased CIN, TMB, SCNV and altered MAPK/ERK pathway. Independent tumors with obviously molecular heterogeneity were revealed in majority of MFLCs while metastasis might exist. Patients with SMPLCs had the tendency to harbour shared EGFR driver L858R. Citation Format: Naixin Liang, Zhongxing Bing, Yang Song, Yadong Wang, Yanyu Wang, Pancheng Wu, Ziqi Jia, Xiaoying Yang, Lei Cao, Zhili Cao, Ruoying Yu, Rui Liu, Qiuxiang Ou, Hua Bao, Xue Wu, Peng Liu, Shuyang Zhang, Shanqing Li. Clonal heterogeneity and evolution of multifocal lung cancers revealed by whole exome sequencing to facilitate molecular diagnosis of multiple primary lung cancers [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 5887.

Abstract 5776: Factors associated with low-dose CT lung cancer screening adherence in a high burden state

Abstract Background: Lung cancer is the leading cause of cancer death in the U.S. The burden of lung cancer varies substantially by region and state, primarily due to historical differences in the prevalence of cigarette smoking. As of 2013, the United States Preventive Services Task Force (USPSTF) recommends lung cancer screening (LCS) with low-dose computed tomography (LDCT) for those meeting eligibility criteria. Given the recency of this recommendation, studies regarding eligibility and participation are sparse. Identifying screening participation rates and subpopulations with lower participation is an essential first step for planning targeted interventions. Therefore, the purpose of this study was to examine LCS eligibility, utilization, and factors associated with self-reported adherence in Oklahoma, a state with a high smoking prevalence rate and low lung cancer survival rate. Methods: Starting in 2017, CDC released an optional Behavioral Risk Factor Surveillance System (BRFSS) module for LCS. Data from 596 LDCT eligible participants from the 2017 and 2018 Oklahoma BRFSS surveys were used for this study. This analysis was restricted to data from individuals eligible for screening based on USPSTF guidelines. Univariate analyses using Rao-Scott Chi-square tests were performed to test for differences in the characteristics of those screened and not screened. Weighted logistic regression models were conducted to examine the importance of independent variables in odds of LCS services. Results: Approximately 5.0% of Oklahomans were eligible for LCS. Only 11.31% (95% CI: 8.02, 14.60) of eligible Oklahomans reported participating in LCS. Asthma diagnosis (p=0.0327), chronic obstructive pulmonary disease (COPD) diagnosis (p<0.0001), and general health status (p=0.0141) were all significantly associated with screening participation; however, urban/rural status (p=0.091), insurance status (p=0.9272), veteran status (p=0.2508), multiple chronic conditions (p=0.0624), and current smoking status (p=0.5099) were not. After adjusting for age, socio-economic factors (income, education, race), asthma status and general health status, the odds of participating in LCS was higher (OR=2.85; 95% CI: 1.40, 5.76; p=0.0037) among those with COPD compared to those without COPD. After the same adjustments the odds of LCS, specifically for males, was even greater among individuals with COPD (OR= 5.86; 95% CI: 2.36, 14.57; p=0.0002) than those without COPD; however, this relationship was not true for females (OR= 0.75; 95% CI: 0.27, 2.08; p=0.5744). Conclusion: Despite the known benefits of LCS, utilization remains suboptimal among individuals in a high-risk state. State estimates and identification of factors associated with LCS adherence may help inform LCS interventions. Citation Format: Ami E. Sedani, Lance Ford, Laura Beebe. Factors associated with low-dose CT lung cancer screening adherence in a high burden state [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 5776.

Use of routine computed tomography scans for detecting osteoporosis in thoracolumbar vertebral bodies.

This study observed the distribution of CT attenuation values for T10-L3 vertebral bodies and derived the Hounsfield unit (HU) thresholds using the quantitative computed tomography (QCT) as a reference to predict osteoporosis and normal bone density. We included 482 subjects who were scheduled to undergo CT lung cancer screening and pulmonary nodule follow-up from May 2015 to February 2019. The subjects were scanned with the calibration phantom beneath the back while performing a chest CT scan. The volumetric bone mineral density (vBMD) and CT attenuation values of T10-L3 vertebral bodies were measured, and the correlation between the two measurements was analyzed. Receiver operator characteristic (ROC) curves were generated to determine diagnostic optimal thresholds. A total of 2716 vertebral bodies of 457 participants were measured after exclusion screening. CT attenuation value of each plane's vertebral body showed a strong correlation with vBMD. The optimal threshold of > 141HU was 93.5% sensitive and 86.1% specific for the recognition of normal BMD. The optimal threshold of < 102.4HU was 96.9% specific and 82.1% sensitive for distinguishing osteoporosis from osteopenia and normal BMD. The average CT attenuation values of vertebral bodies with compressed and normal morphology were 108.9 ± 20.6 and 136.8 ± 32.2HU, respectively. Sagittal reconstruction of the thoracic vertebrae using routine thoracic CT image combined with CT attenuation value measurements of the spine is valuable for predicting bone mineral density in high-risk populations. The mean CT attenuation values of the vertebral bodies with vertebral compression appearance were lower than that of normal vertebral shape.

Clinicopathologic and Longitudinal Imaging Features of Lung Cancer Associated With Cystic Airspaces: A Systematic Review and Meta-Analysis.

BACKGROUND. Lung cancer (LC) associated with cystic airspaces is an uncommon presentation that is underrecognized on imaging. Additionally, understanding of its underlying pathology and risk factors is limited, which can contribute to delays in diagnosis. OBJECTIVE. The purpose of this analysis was to systematically review, analyze, and synthesize the medical literature to determine the imaging features of LC associated with cystic airspaces. EVIDENCE ACQUISITION. In accordance with Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines, we included published research reporting the clinical, pathologic, and imaging features of LC associated with cystic airspaces. We then performed a pooled analysis of continuous and categoric data with respect to patient clinical characteristics, tumor pathologic features, underlying driver mutation, CT features, and evolution of these features over time. EVIDENCE SYNTHESIS. The analysis included eight original observational studies with a combined total of 341 patients with LC associated with cystic airspaces (weighted mean age, 61.8 years; range, 30-87 years; 135 women and 206 men). Most patients were current or previous smokers (127/192 [66.1%]). The most common histologic finding was adenocarcinoma (289/328 [88.1%]) followed by squamous cell carcinoma (30/328 [9.1%]). The most common driver mutations were EGFR (46/122 [37.7%]) and KRAS (21/122 [17.2%]). The cysts in LC associated with cystic airspaces commonly had nonuniform (104/114 [91.2%]) and thick (83/222 [37.4%]) walls, irregular margins (53/142 [37.3%]), and were unilocular (173/272 [63.6%]). Most cysts had a nodular component (210/328 [64.0%]). Over time, most cysts showed development or enlargement of the nodular component (61/89 [68.5%]), approximately half showed wall thickening (43/89 [48.3%]), and a minority evolved into completely solid lesions (11/89 [12.4%]). The size of the cystic component increased in 36 of 89 patients (40.4%), decreased in 28 (31.5%), and remained stable in 24 (27.0%). CONCLUSION. LC associated with cystic airspaces occurs most commonly as adeno-carcinoma and is seen in both smokers and nonsmokers. The cysts associated with LC show wall thickening and mural nodularity, which may evolve over time. LC associated with cystic airspaces can be indolent, and long-term surveillance with imaging should be considered if cysts are not resected. CLINICAL IMPACT. Familiarity with the imaging features and temporal evolution of LC associated with cystic airspaces can minimize delays in LC diagnosis. Future management guidelines should include protocols for follow-up and management of cystic lung lesions identified during diagnostic and LC screening CT.

Lung cancer screening in patients with previous malignancy: Is this cohort at increased risk for malignancy?

To determine the rate of second primary lung cancer (SPLC) and describe the clinical characteristics and radiological findings in individuals with a prior history of cancer presenting to a low-dose computed tomography (LDCT) lung cancer screening program at a tertiary cancer center. Patients with a previous history of malignancy, a life expectancy ≥ 5years referred for CT lung cancer screening between May 2, 2011, and November 28, 2018, were included. Demographics regarding risk factors including smoking history and prior history of thoracic radiation were collected. CT scan features assessed nodule size, morphologic features, and number. The Lung-CT Reporting and Data System (Lung-RADS) scoring system was retrospectively applied to studies performed before October 2014 and prospectively applied to remainder of studies. Data was collected in a Health Insurance Portability and Accountability Act (HIPAA)-compliant manner. A total of 543 patients were studied (mean age of 66years). All had a previous history of cancer, most commonly breast cancer 205 (38%), head and neck cancer 105 (19%), and lung cancer 87 (16%). Of screening CTs performed, 17.5% were positive screening study results as per Lung-RADS scoring system. SPLC was diagnosed in 35 patients (6.4%) with 21 prevalence cancers detected and 14 interval cancers detected in subsequent screening rounds. The rate of screen-detected SPLC in patients with prior malignancy is higher than reported rates seen in historical prospective screening studies. Our study suggests the need for prospective research to evaluate any mortality benefit that screening may have in this population. • The rate of screen-detected second primary lung cancer in patients with prior malignancy is higher than reported rates seen in historical prospective randomized lung cancer screening studies in a general screened population. • Patients with a prior malignancy undergoing lung cancer screening have higher rates of positive screening studies and higher rates of invasive diagnostic procedures than those reported in a general screening population. • Prospective research is required to evaluate if screening offers a mortality benefit in this population.

Impact Of 2016 SCCT/STR Guidelines For Coronary Artery Calcium Scoring Of Noncardiac Chest CT Scans On Lung Cancer Screening CT Reporting

Introduction: Coronary artery calcification (CAC) reporting on lung cancer screening (LCS) CT scans can provide an untapped resource to obtain risk data for initiating preventive therapy. Prior studies have consistently shown under-reporting of CAC on CT scans. The 2016 SCCT/STR guideline for CAC scoring on NCCT scans explicitly calls for reporting of CAC, even if not specifically requested by the ordering physician. Whether the publication of the 2016 SCCT/STR guideline has had any impact on CAC reporting in LCS scans has not been investigated. We hypothesized that CAC on LCS scans is prevalent and under-reported, and aimed to assess the impact of the guideline on CAC reporting.

Lung Cancer Screening with Low-Dose CT: a Meta-Analysis.

Randomized controlled trials have evaluated the efficacy of low-dose CT (LDCT) lung cancer screening on lung cancer (LC) outcomes. Meta-analyze LDCT lung cancer screening trials. We identified studies by searching PubMed, Google Scholar, the Cochrane Registry, ClinicalTrials.gov , and reference lists from retrieved publications. We abstracted data on study design features, stage I LC diagnoses, LC and overall mortality, false positive results, harm from invasive diagnostic procedures, overdiagnosis, and significant incidental findings. We assessed study quality using the Cochrane risk-of-bias tool. We used random-effects models to calculate relative risks and assessed effect modulators with subgroup analyses and meta-regression. We identified 9 studies that enrolled 96,559 subjects. The risk of bias across studies was judged to be low. Overall, LDCT screening significantly increased the detection of stage I LC, RR = 2.93 (95% CI, 2.16-3.98), I2 = 19%, and reduced LC mortality, RR = 0.84 (95% CI, 0.75-0.93), I2 = 0%. The number needed to screen to prevent an LC death was 265. Women had a lower risk of LC death (RR = 0.69, 95% CI, 0.40-1.21) than men (RR = 0.86, 95% CI, 0.66-1.13), p value for interaction = 0.11. LDCT screening did not reduce overall mortality, RR = 0.96 (95% CI, 0.91-1.01), I2 = 0%. The pooled false positive rate was 8% (95% CI, 4-18); subjects with false positive results had < 1 in 1000 risk of major complications following invasive diagnostic procedures. The most valid estimates for overdiagnosis and significant incidental findings were 8.9% and 7.5%, respectively. LDCT screening significantly reduced LC mortality, though not overall mortality, with women appearing to benefit more than men. The estimated risks for false positive results, screening complications, overdiagnosis, and incidental findings were low. Long-term survival data were available only for North American and European studies limiting generalizability.

Psychosocial consequences of false positives in the Danish Lung Cancer CT Screening Trial: a nested matched cohort study

ObjectivesLung cancer CT screening can reduce lung cancer mortality, but high false-positive rates may cause adverse psychosocial consequences. The aim was to analyse the psychosocial consequences of false-positive lung cancer...

Extent of implementation of low-dose CT in lung cancer screening.

e19177 Background: Lung cancer is the leading cause of cancer deaths in the United States with only 15% alive 5 years after diagnosis. In 2013, USPSTF recommended annual screening for LDCT in high risk individuals. Studies had shown a 20% lower mortality (NELSON trial showed significantly lower lung cancer mortality) with LDCT screening. We aimed to assess the extent to which the guideline for lung cancer screening is being adopted in a community clinic. Methods: A retrospective review of electronic medical record of patients aged 55-80 years with no history of lung cancer who visited a primary care provider in a community clinic in New Jersey from October 2014- December 2019 was done. All records with any form of documentation of smoking were identified electronically. The records of those meeting the criteria (30 pack-year smoking history and currently smoking or have quit within the past 15 years) were reviewed manually to check 1) whether they are eligible for screening, 2) if eligible whether low dose CT has been recommended by the provider and 3) once recommended has it been done and followed by the patients. Results: 359 individuals with documented smoking history were identified. Of those 38.8 % (139/359) had a proper documentation (includes both PPD and number of years of smoking) of smoking history based on which high risk individuals could be identified. Of those 37 individuals met the criteria for lung cancer screening. 62% (23/37) had CT chest ordered at some point of time (16.2% for a different indication and the rest for lung cancer screening). Only 52.2% (12/23) of the patients followed the recommendations and got a LDCT done. Among those 50% (6/12) had follow up CT, 50 % (3/6) of those did it on a regular annual basis while the rest 50% (3/6) did it irregularly. 3 patients followed the annual CT screening for lung cancer. Conclusions: Based on these we note that almost half a decade since the recommendation has been established only a small proportion received the care and a still smaller minority followed it. It reflects the dearth of information regarding the guideline among providers and the lack of awareness of the need to follow among patients. This puts forward need for further interventions for implementation of the guidelines at all levels of care for lung cancer prevention. Measures include analyzing the areas of deficiency through questionnaires for patients and providers. Creating awareness on the need for accurate documentation of smoking history and the impact it can have on care delivered. Educating patients about the benefits in health outcome by following the recommendations.

Review of annual compliance of low-dose CT for lung cancer screening among internal medicine resident physicians in a university teaching program.

e19187 Background: Lung cancer remains the leading cause of morbidity and mortality, with an estimated 2.1 million newly diagnosed cases each year. A large percentage of cases are detected at an advanced stage, making treatment recalcitrant. Only about 15% are diagnosed at an early stage, highlighting the significance of timely screening. USPSTF recommends annual screening with low-dose computed tomography (LDCT) in adults aged 55-80, who have a 30 pack-year smoking history and are current smokers, or former smokers who have quit within the last 15 years. The National Comprehensive Cancer Network (NCCN) guidelines, as well as the National Lung Screening Trial (NLST), recommend annual screening with LDCT until a person is no longer a candidate for definitive treatment. This study aimed to evaluate the compliance with annual LDCT based on USPSTF guidelines among internal medicine residents from the University of Connecticut residency program at a Clinic in Hartford, Connecticut, USA. Methods: Patients who were under the care of internal medicine residents and who had undergone an initial LDCT for lung cancer screening were included. A total of 61 medical charts were reviewed. Three patients were diagnosed with lung cancer and nineteen patients had their initial LDCT in 2019, and therefore excluded. Results: Out of the 39 patients, 10 patients (25.64%) had a follow-up annual LDCT performed, 2 patients before the annual mark due to various clinical concerns, and 9 patients (23%) in the following 24-48 months. 6 patients (15.38%) had a repeat LDCT ordered but was not done or it was canceled. 12 patients (30.77%) had no repeat LDCT ordered at 12 months. Overall, 69.23% had no follow-up CT at 12 months, and 46.15% with no follow up CT at all at the time of chart review. Conclusions: Based on our analysis, follow-up annual LDCT scans for lung cancer screening on patients under the care of residents-in-training are not being ordered frequently enough. The failure to order annual LDCT could be due to a false sense of relief with a normal initial LDCT, the lack of provider’s awareness of USPSTF guidelines, or insurance issues. Educating primary care providers on the importance of follow-up annual LDCT will ensure early detection and decrease mortality from lung cancer in high risk patient population.

Deep learning to identify high-risk smokers for lung cancer screening from chest radiographs.

1519 Background: Appearance on chest radiography may inform selection of high-risk smokers for lung cancer screening CT, beyond Centers for Medicare &amp; Medicaid Services (CMS) eligibility criteria. Methods: A convolutional neural network (CXR-LC) predicting 12-year incident lung cancer from the chest radiograph image, age, sex, and smoking status (current/former) was developed in 41,856 persons aged 55-74 from the Prostate, Lung, Colorectal &amp; Ovarian trial (PLCO). The final model was tested in held-out smokers from PLCO (n=5,615, 37.9% CMS eligible, 12-year follow-up), and externally in the National Lung Screening Trial (NLST, n=5,493, all CMS eligible, 6-year follow-up). Sensitivity was compared at a fixed screening population size defined by CMS eligibility. Ordinal CXR-LC risk score (low/indeterminate/high/very high) was based on development dataset 12-year probability thresholds (&lt;2%/2-&lt;3.3%/3.3-&lt;8%/≥8%). Results are provided in test datasets only. Results: In the PLCO test dataset, CXR-LC was more sensitive than CMS eligibility at a fixed screening population size (74.9% vs. 63.8%, p=0.01) and missed 30.8% fewer lung cancers. CXR-LC risk groups were associated with incident lung cancer in PLCO test dataset smokers (very high vs. low CXR-LC risk: 12.4 vs 1.1 lung cancers/1,000 person-years) with external testing in NLST (all CMS eligible: 12.7 vs 2.3) (Table). This association was robust to adjustment for radiologist findings and the PLCOm2012 risk score. Conclusions: CXR-LC identified smokers at high risk of incident lung cancer, beyond CMS eligibility. [Table: see text]

Lung Cancer CT Screening and Lung-RADS in a Tuberculosis-endemic Country: The Korean Lung Cancer Screening Project (K-LUCAS)

Background Low-dose CT screening for lung cancer in a tuberculosis-endemic country may be less effective because of false-positive results caused by tuberculosis sequelae. Purpose To evaluate the impact of tuberculosis sequelae at CT screening according to the American College of Radiology Lung CT Screening Reporting and Data System (Lung-RADS) using data from the Korean Lung Cancer Screening Project (K-LUCAS). Materials and Methods This is a secondary analysis of K-LUCAS (ClinicalTrials.gov identifier NCT03394703), a nationwide Asian population-based, multicenter, prospective cohort study. Participants at high risk for lung cancer were enrolled between April 2017 and December 2018. Associations of tuberculosis sequelae with a positive screening result for lung cancer (defined as Lung-RADS categories 3 or 4) and diagnosis of lung cancer were analyzed with multivariable logistic regression. The diagnostic performance of Lung-RADS in predicting lung cancer was compared between participants with and participants without tuberculosis sequelae by using the χ2 test. Results A total of 11 394 participants (median age, 62 years; interquartile range, 58-67 years; 11 098 men) were evaluated. Positive screening results were found in 1868 of the 11 394 participants (16%); lung cancer was diagnosed in 65 of the 11 394 participants (0.6%). Tuberculosis sequelae were identified in 1509 of the 11 394 participants (13%) on the basis of CT scans. Tuberculosis sequelae were associated with positive CT screening results (odds ratio [OR] with one nodule, 1.22; 95% confidence interval [CI]: 1.02, 1.45; P = .03), but no evidence was found of an association with lung cancer (OR, 0.9; 95% CI: 0.4, 1.6; P = .64). Specificity of Lung-RADS was higher for participants without tuberculosis sequelae (85% [8327 of 9829 participants]; 95% CI: 84.0%, 85.4%) than for those with tuberculosis sequelae (80% [1198 of 1500 participants]; 95% CI: 77.7%, 82%; P < .001). Sensitivity was not different between participants with tuberculosis sequelae (100% [nine of nine participants]; 95% CI: 62.9%, 100%) and those without tuberculosis sequelae (98% [55 of 56 participants]; 95% CI: 89.2%, 99.9%; P > .99). Conclusion In an at-risk population, tuberculosis sequelae resulted in a reduced specificity of CT screening for lung cancer using the Lung CT Screening Reporting and Data System. © RSNA, 2020 Online supplemental material is available for this article. See also the editorial by Ketai in this issue.

Meeting ACR Dose Guidelines for CT Lung Cancer Screening in an Overweight and Obese Population

Lung cancer screening adoption coincides with a growing obesity epidemic. Maintaining high-quality imaging at low radiation dose is challenging in obesity. We investigate the feasibility of meeting American College of Radiology (ACR) dose guidelines for lung cancer screening in a predominantly overweight and obese population. Radiation dose (Volumetric CT dose index [CTDIvol], dose-length product), and body mass index (BMI) were collected for baseline screening CTs December, 2012-December, 2017. Dose metrics were analyzed according to BMI classification (normal <25, overweight 25-29, obese ≥30 kg/m2), using k = 0.014 mSv/mGy*cm. Results were compared to ACR dose guidelines and mean national 2017 Lung Cancer Screening Registry dose metrics. Analysis used Kruskal-Wallis (SPSS, version 24.0.0, IBM corp, Armonk, NY). Study population comprised 1478 patients (49.2% [727] women: mean BMI 28.1 ± 6.5 kg/m2, 26.9% [397] normal weight, 35.9% [530] overweight, 37.2% [551] obese). ACR dose requirements were met for both genders in all BMI classifications. Dose metrics were higher in men than in women; median effective dose and CTDIvol were 1.39 (0.8-1.58) mSv and 2.78 (1.41-2.80) mGy in men versus 1.16 (0.71-1.43) mSv and 2.70 (1.4-2.78) mGy in women. There were significant differences in dose metrics between men and women in the same BMI classification and between BMI classifications (p < 0.001). Mean dose metrics in our program were considerably lower than 2017 national average- mean CTDIvol and effective dose 2.45 ± 1.14 mGy and 1.26 ± 0.59 mSv versus 3.24 mGy and 1.35 mSv, respectively for our program and nationally. Mean dose metrics were also lower in our obese patients versus obese patients nationally. ACR dose metrics for lung cancer screening were met and can be appropriately tailored in a predominantly overweight and obese population clinical program.

Patient size matters: Effect of tube current modulation on size-specific dose estimates (SSDE) and image quality in low-dose lung cancer screening CT.

PurposeWe compare the effect of tube current modulation (TCM) and fixed tube current (FTC) on size‐specific dose estimates (SSDE) and image quality in lung cancer screening with low‐dose CT (LDCT) for patients of all sizes.MethodsInitially, 107 lung screening examinations were performed using FTC, which satisfied the Centers for Medicare & Medicaid Services' volumetric CT dose index (CTDIvol) limit of 3.0 mGy for standard‐sized patients. Following protocol modification, 287 examinations were performed using TCM. Patient size and examination parameters were collected and water‐equivalent diameter (Dw) and SSDE were determined for each patient. Regression models were used to correlate CTDIvol and SSDE with Dw. Objective and subjective image quality were measured in 20 patients who had consecutive annual screenings with both FTC and TCM.ResultsCTDIvol was 2.3 mGy for all FTC scans and increased exponentially with Dw (range = 0.96–4.50 mGy, R2 = 0.73) for TCM scans. As patient Dw increased, SSDE decreased for FTC examinations (R2 = 1) and increased for TCM examinations (R2 = 0.54). Image quality measurements were superior with FTC for smaller sized patients and with TCM for larger sized patients (R2 > 0.5, P < 0.005). Radiologist graded all images acceptable for diagnostic evaluation of lung cancer screening.ConclusionAlthough FTC protocol offered a consistently low CTDIvol for all patients, it yielded unnecessarily high SSDE for small patients and increased image noise for large patients. Lung cancer screening with LDCT using TCM produces radiation doses that are appropriately reduced for small patients and increased for large patients with diagnostic image quality for all patients.

Advancement in Low-dose CT Screening for Lung Cancer

米国におけるNLST（National Lung Screening Trial），欧州におけるNELSON（Dutch-Belgian randomized lung cancer screening trial）の2つのランダム化比較試験により，高危険群に対する低線量CT（low-dose computed tomography：LDCT）検診による肺癌死亡減少効果が証明された．NLSTでは胸部X線（chest X-ray：CXR）検診に対する，NELSONでは無検診に対する有用性である．ただし，対照の違いに加え，肺癌死亡減少割合，過剰診断割合は観察期間によって変化するため，2試験の単純な比較は困難である．既に，米国では保険による実施が開始されたが，実用化に際しては問題点も抽出されつつある．今後，日本において実用化するには，非～軽喫煙者に対する有用性評価，検診の実施体制（対策型検診及び任意型検診）の確立に加え，computer-aided diagnosis（CAD），人工知能（artificial intelligence：AI）ならびにバイオマーカー技術等の導入による高効率化と省力化，実施施設，読影医ならびに放射線技師等のインフラ整備とこれらの質の担保が必要となり，このための研究が必要となる．

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.

Leveraging the Mammography Setting to Raise Awareness and Facilitate Referral to Lung Cancer Screening: A Qualitative Analysis.

Despite compelling support for the benefits of low-dose CT (LDCT) screening for lung cancer among high-risk individuals, awareness of LDCT screening and uptake remain low. The aim of this project was to explore the perspectives of ACR mammography screening program directors (MPDs) regarding efforts to raise LDCT screening awareness and appropriate referrals by identifying high-risk individuals participating in routine mammography. MPDs were recruited from ACR-accredited mammography facilities to participate in semistructured interviews after the completion of an online survey. Interviews were conducted over the telephone, recorded, transcribed, and subsequently reviewed for accuracy. Twenty MPDs were interviewed, and 18 interviews were transcribed and included in the thematic analysis. A theme codebook was developed, and all interviews were coded using NVivo by two trained reviewers. Key themes were organized into four broad domains: (1) general attitudes toward the integration of LDCT screening, (2) identifying mammography patients at high risk for lung cancer, (3) counseling about LDCT screening, and (4) strategies to identify high-risk women and increase awareness and knowledge of LDCT screening. Overall, MPDs recognized the benefits of integrating mammography and LDCT screening and were receptive to educating and referring women for LDCT screening. However, training and workflow changes are needed to ensure successful implementation. Qualitative data suggest that MPDs are amenable to leveraging the mammography setting to engage women about LDCT screening; however, additional tools, training, and/or staffing may be necessary to leverage the full potential of reaching women at high risk for lung cancer within the context of mammographic screening.

The OaSiS trial: A hybrid type II, national cluster randomized trial to implement smoking cessation during CT screening for lung cancer

IntroductionWhen the Centers for Medicare and Medicaid Services announced coverage for low dose CT lung cancer screening, they also mandated that imaging centers offer smoking cessation services. We designed the Optimizing Lung Screening (OaSiS) trial to evaluate strategies to implement the Public Health Service Guidelines for Treating Tobacco Use and Dependence during CT screening for lung cancer. Methods and designOaSiS was implemented using a pragmatic effectiveness-implementation hybrid design in 26 imaging clinics across the United States affiliated with the National Cancer Institute's National Community Oncology Research Program (NCORP). The 26 sites selected for participation in the OaSiS trial were randomized to receive either a compendium of implementation strategies to add or enhance smoking cessation services during lung screening or to usual care. Usual care sites were given the option to receive the full compendium of implementation strategies at the conclusion of data collection. We have evaluated both the effectiveness of the implementation strategies to improve smoking cessation at six months among patients undergoing LDCT screening as well as the adoption and sustainability of evidence-based tobacco cessation strategies in imaging clinics. DiscussionThe OaSiS trial was designed to identify opportunities for implementing evidence-based smoking cessation into LDCT lung cancer screening imaging facilities and to establish the effectiveness of these services. We report our study design and evaluation, including strengths of the pragmatic design and the inclusion of a diverse range of screening programs. Establishing these tobacco cessation services will be critical to reducing smoking related morbidity and mortality.