ESR/ERS white paper on lung cancer screening

Pulmonary nodule detection in low dose computed tomography using a medical-to-medical transfer learning approach

Purpose

Lung cancer is the second most common cancer and the leading cause of cancer death globally. Low dose computed tomography (LDCT) is the recommended imaging screening tool for the early detection of lung cancer. A fully automated computer-aided detection method for LDCT will greatly improve the existing clinical workflow. Most of the existing methods for lung detection are designed for high-dose CTs (HDCTs), and those methods cannot be directly applied to LDCTs due to domain shifts and inferior quality of LDCT images. In this work, we describe a semi-automated transfer learning-based approach for the early detection of lung nodules using LDCTs.

Approach

In this work, we developed an algorithm based on the object detection model, you only look once (YOLO) to detect lung nodules. The YOLO model was first trained on CTs, and the pre-trained weights were used as initial weights during the retraining of the model on LDCTs using a medical-to-medical transfer learning approach. The dataset for this study was from a screening trial consisting of LDCTs acquired from 50 biopsy-confirmed lung cancer patients obtained over 3 consecutive years (T1, T2, and T3). About 60 lung cancer patients' HDCTs were obtained from a public dataset. The developed model was evaluated using a hold-out test set comprising 15 patient cases (93 slices with cancerous nodules) using precision, specificity, recall, and F1-score. The evaluation metrics were reported patient-wise on a per-year basis and averaged for 3 years. For comparative analysis, the proposed detection model was trained using pre-trained weights from the COCO dataset as the initial weights. A paired t-test and chi-squared test with an alpha value of 0.05 were used for statistical significance testing.

Results

The results were reported by comparing the proposed model developed using HDCT pre-trained weights with COCO pre-trained weights. The former approach versus the latter approach obtained a precision of 0.982 versus 0.93 in detecting cancerous nodules, specificity of 0.923 versus 0.849 in identifying slices with no cancerous nodules, recall of 0.87 versus 0.886, and F1-score of 0.924 versus 0.903. As the nodule progressed, the former approach achieved a precision of 1, specificity of 0.92, and sensitivity of 0.930. The statistical analysis performed in the comparative study resulted in a p -value of 0.0054 for precision and a p -value of 0.00034 for specificity.

Conclusions

In this study, a semi-automated method was developed to detect lung nodules in LDCTs using HDCT pre-trained weights as the initial weights and retraining the model. Further, the results were compared by replacing HDCT pre-trained weights in the above approach with COCO pre-trained weights. The proposed method may identify early lung nodules during the screening program, reduce overdiagnosis and follow-ups due to misdiagnosis in LDCTs, start treatment options in the affected patients, and lower the mortality rate.

HUNCHEST projects-advancing low-dose CT lung cancer screening in Hungary

Lung cancer, the leading cause of malignancy-related deaths worldwide, demands proactive measures to mitigate its impact. Low-dose computer tomography (LDCT) has emerged as a promising tool for secondary prevention through lung cancer screening (LCS). The HUNCHEST study, inspired by the success of international trials, including the National Lung Cancer Screening Trial and the Dutch NELSON study, embarked on the first LDCT-based LCS program in Hungary. The initiative assessed the screening efficiency, incorporating lung function tests and exploring the interplay between lung cancer and chronic obstructive pulmonary disease (COPD). Building upon this foundation, an implementation trial involving 18 Hungarian centers supported by the Ministry of Human Capacities demonstrated the feasibility of LCS within a multicentric framework. These centers, equipped with radiology capabilities, collaborated with multidisciplinary oncology teams, ensuring optimal patient pathways. However, a critical challenge remained the patient recruitment. To address this, the HUNCHEST 3 project, initiated in 2023, seeks to engage general practitioners (GPs) to reach out to eligible patients within a municipality collective of 60 thousand inhabitants. The project's ultimate success is contingent upon the willingness of eligible individuals to undergo LDCT scans. In conclusion, the HUNCHEST program represents a crucial step in advancing lung cancer screening in Hungary. With a focus on efficiency, multidisciplinary collaboration, and innovative patient recruitment strategies, it endeavors to contribute to the reduction of lung cancer mortality and serve as a blueprint for potential nationwide LCS programs.

Hemorrhage risk prediction after computed tomography-guided lung biopsy: Clinical parameters and quantitative pulmonary vascular analysis

BACKGROUND/PURPOSE

We evaluated the utility of combining quantitative pulmonary vasculature measures with clinical factors for predicting pulmonary hemorrhage after computed tomography (CT)-guided lung biopsy.

METHODS

Patients who underwent CT-guided lung biopsy were retrospectively included in this study. Clinical and radiographic vasculature variables were evaluated as predictors of pulmonary hemorrhage. The radiographic pulmonary vascular analysis included vessel count, density, diameter, and area, and also blood volume in small vessels with a cross-sectional area ≤5 mm2 (BV5) and total blood vessel volume (TBV) in the lungs. Univariate and multivariate logistic regressions were used to identify the independent risk factors of higher-grade pulmonary hemorrhage and establish the prediction model presented as a nomogram.

RESULTS

The study included 126 patients; discovery cohort n = 103, and validation cohort n = 23. All pulmonary hemorrhage, higher-grade (grade ≥2) pulmonary hemorrhage, and hemoptysis occurred in 42.9%, 15.9%, and 3.2% of patients who underwent CT-guided lung biopsies. In the discovery cohort, patients with larger lesion depth (p = 0.013), higher vessel density (p = 0.033), and higher BV5 (p = 0.039) were more likely to experience higher-grade hemorrhage. The nomogram prediction model for higher-grade hemorrhage built by the discovery cohort showed similar performance in the validation cohort.

CONCLUSIONS

Higher-grade pulmonary hemorrhage may occur after CT-guided lung biopsy. Lesion depth, vessel density, and BV5 are independent risk factors for higher-grade pulmonary hemorrhage. Nomograms integrating clinical parameters and radiographic pulmonary vasculature measures offer enhanced capability for assessing hemorrhage risk following CT-guided lung biopsy, thereby facilitating improved patient clinical care.

A Bibliometric Analysis of Comorbidity of COPD and Lung Cancer: Research Status and Future Directions

Objective

Although studies on the association between COPD and lung cancer are of great significance, no bibliometric analysis has been conducted in the field of their comorbidity. This bibliometric analysis explores the current situation and frontier trends in the field of COPD and lung cancer comorbidity, and to lay a new direction for subsequent research.

Methods

Articles in the field of COPD and cancer comorbidity were retrieved from Web of Science Core Collections (WoSCC) from 2004 to 2023, and analyzed by VOSviewer, CiteSpace, Biblimatrix and WPS Office.

Results

In total, 3330 publications were included. The USA was the leading country with the most publications and great influence. The University of Groningen was the most productive institution. Edwin Kepner Silverman was the most influential scholar in this field. PLOS One was found to be the most prolific journal. Mechanisms and risk factors were of vital importance in this research field. Environmental pollution and pulmonary fibrosis may be future research prospects.

Conclusion

This bibliometric analysis provided new guidance for the development of the field of COPD and lung cancer comorbidity by visualizing current research hotspots, and predicting possible hot research directions in the future.

Recruitment strategies and interventions to increase participation in lung cancer screening programmes: a systematic review protocol

INTRODUCTION

Despite strong evidence for the efficacy of low-radiation dose CT (LDCT) in reducing lung cancer (LC) mortality, implementing LC screening (LCS) programmes remains a challenge. We aim to systematically review the evidence on the strategies used to recruit the adult population at risk of LC to LDCT within LCS programmes and to estimate the effectiveness of interventions identified, used to reach the potentially eligible population, increase participation and informed choice, and ensure equitable access.

METHODS AND ANALYSIS

This sequential systematic literature review will consist of three steps: (1) a scoping review of existing strategies and organisational models for LCS; (2) selecting papers reporting relevant outcomes (test coverage, screening participation and informed choice) and comparing results among different models; (3) a systematic review of interventions implemented to increase participation in LCS programmes. Each step will follow the methodological guidelines provided by the Cochrane Collaboration and the Preferred Reporting Items for Systematic Reviews and Meta-Analyses statement. Data sources include electronic databases such as Medline (PubMed version), Embase, CINAHL (Ebsco version), Scopus and Cochrane CENTRAL. The search will be limited to studies published from January 2000 to March 2023 in English, Italian, French, Spanish, Serbian and Croatian language. Findings will be synthesised quantitatively and qualitatively as appropriate. Risk of bias assessment will be only applied to studies selected in the second and third steps. The quality of evidence will be summarised for each outcome using the Grading Recommendation Assessment, Development and Evaluation methodology.

ETHICS AND DISSEMINATION

Given that this is a review of existing literature, ethics approval is not required. The results will be published in peer-reviewed scientific journals and presented at relevant conferences. The findings of this review will help guide health authorities in organising LCS programmes and developing recommendations, policies, and actions at national and regional levels.

PROSPERO REGISTRATION NUMBER

CRD42023408357.

Malignant Nodules Detected on Lung Cancer Screening CT: Yield of Short-Term Follow-Up CT in Showing Nodule Growth

BACKGROUND. Lung-RADS recommends 3-month follow-up for category 4A nodules and downgrading to category 2 of all category 3 or 4 nodules that are unchanged for 3 months or longer, indicating benign behavior. This guidance may be problematic considering the potential for slow-growing cancers in that lack of nodule growth, particularly at short follow-up intervals, may provide false reassurance. OBJECTIVE. The purpose of this study was to evaluate the yield of short-term follow-up CT in showing growth among malignant nodules detected on lung cancer screening CT. METHODS. This retrospective study included 76 patients (53 women, 23 men; median age, 68 years) with a positive lung cancer screening CT result (Lung-RADS category ≥ 3) between June 2015 and May 2021 with a subsequent lung cancer diagnosis and at least one follow-up CT examination at least 3 months before diagnostic or therapeutic intervention. Semiautomated software was used for linear and volumetric nodule measurements. Diameter was defined as the mean of short- and long-axis measurements. For solid nodules, growth was defined as an at least 1.5-mm increase in mean diameter or an at least 25% increase in volume; part-solid nodules, an at least 1.5-mm increase in solid-component mean diameter or an at least 25% increase in volume; and ground-glass nodules, an at least 3-mm increase in mean diameter or development of a new solid component within the nodule. RESULTS. Median time to growth was 13 months by linear and 11 months by volumetric measurement. Frequency of growth at 3 months was 5% by linear and 7% by volumetric measurement. By linear measurement, median time to growth and frequency of growth at 3 months were 13 months and 7% (solid nodules), 18 months and 6% (part-solid nodules), not reached and 0% (ground-glass nodules), not reached and 0% (category 3 nodules), 13 months and 6% (category 4A nodule)s, 6 months and 11% (category 4B nodules), and 12 months and 10% (category 4X nodules). CONCLUSION. Malignant nodules manifest growth slowly on follow-up CT, and 3-month follow-up CT has very low yield. Stability at 3-month follow-up should not instill high confidence in benignancy, and downgrading all such nodules to Lung-RADS category 2 may be problematic. CLINICAL IMPACT. This study highlights the possibility of slow-growing malignancy and associated challenges in application of Lung-RADS to management of unchanged nodules on follow-up imaging.

The Use of Breath Analysis in the Management of Lung Cancer: Is It Ready for Primetime?

Breath analysis is a promising non-invasive method for the detection and management of lung cancer. Exhaled breath contains a complex mixture of volatile and non-volatile organic compounds that are produced as end-products of metabolism. Several studies have explored the patterns of these compounds and have postulated that a unique breath signature is emitted in the setting of lung cancer. Most studies have evaluated the use of gas chromatography and mass spectrometry to identify these unique breath signatures. With recent advances in the field of analytical chemistry and machine learning gaseous chemical sensing and identification devices have also been created to detect patterns of odorant molecules such as volatile organic compounds. These devices offer hope for a point-of-care test in the future. Several prospective studies have also explored the presence of specific genomic aberrations in the exhaled breath of patients with lung cancer as an alternative method for molecular analysis. Despite its potential, the use of breath analysis has largely been limited to translational research due to methodological issues, the lack of standardization or validation and the paucity of large multi-center studies. It is clear however that it offers a potentially non-invasive alternative to investigations such as tumor biopsy and blood sampling.

Deep Learning Algorithms for Diagnosis of Lung Cancer: A Systematic Review and Meta-Analysis

We conducted a systematic review and meta-analysis of the diagnostic performance of current deep learning algorithms for the diagnosis of lung cancer. We searched major databases up to June 2022 to include studies that used artificial intelligence to diagnose lung cancer, using the histopathological analysis of true positive cases as a reference. The quality of the included studies was assessed independently by two authors based on the revised Quality Assessment of Diagnostic Accuracy Studies. Six studies were included in the analysis. The pooled sensitivity and specificity were 0.93 (95% CI 0.85−0.98) and 0.68 (95% CI 0.49−0.84), respectively. Despite the significantly high heterogeneity for sensitivity (I2 = 94%, p < 0.01) and specificity (I2 = 99%, p < 0.01), most of it was attributed to the threshold effect. The pooled SROC curve with a bivariate approach yielded an area under the curve (AUC) of 0.90 (95% CI 0.86 to 0.92). The DOR for the studies was 26.7 (95% CI 19.7−36.2) and heterogeneity was 3% (p = 0.40). In this systematic review and meta-analysis, we found that when using the summary point from the SROC, the pooled sensitivity and specificity of DL algorithms for the diagnosis of lung cancer were 93% and 68%, respectively.

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.

Detection and staging of chronic obstructive pulmonary disease using a computed tomography-based weakly supervised deep learning approach

OBJECTIVES

Chronic obstructive pulmonary disease (COPD) is underdiagnosed globally. The present study aimed to develop weakly supervised deep learning (DL) models that utilize computed tomography (CT) image data for the automated detection and staging of spirometry-defined COPD.

METHODS

A large, highly heterogeneous dataset was established, consisting of 1393 participants retrospectively recruited from outpatient, inpatient, and physical examination center settings of four large public hospitals in China. All participants underwent both inspiratory chest CT scans and pulmonary function tests. CT images, spirometry data, demographic information, and clinical information of each participant were collected. An attention-based multi-instance learning (MIL) model for COPD detection was trained using CT scans from 837 participants. External validation of the COPD detection was performed with 620 low-dose CT (LDCT) scans acquired from the National Lung Screening Trial (NLST) cohort. A multi-channel 3D residual network was further developed to categorize GOLD stages among confirmed COPD patients.

RESULTS

The attention-based MIL model used for COPD detection achieved an area under the receiver operating characteristic curve (AUC) of 0.934 (95% CI: 0.903, 0.961) on the internal test set and 0.866 (95% CI: 0.805, 0.928) on the LDCT subset acquired from the NLST. The multi-channel 3D residual network was able to correctly grade 76.4% of COPD patients in the test set (423/553) using the GOLD scale.

CONCLUSIONS

The proposed chest CT-DL approach can automatically identify spirometry-defined COPD and categorize patients according to the GOLD scale. As such, this approach may be an effective case-finding tool for COPD diagnosis and staging.

KEY POINTS

• Chronic obstructive pulmonary disease is underdiagnosed globally, particularly in developing countries. • The proposed chest computed tomography (CT)-based deep learning (DL) approaches could accurately identify spirometry-defined COPD and categorize patients according to the GOLD scale. • The chest CT-DL approach may be an alternative case-finding tool for COPD identification and evaluation.

Applications of artificial intelligence in the thorax: a narrative review focusing on thoracic radiology

Objective

This review will focus on how AI—and, specifically, deep learning—can be applied to complement aspects of the current healthcare system. We describe how AI-based tools can augment existing clinical workflows by discussing the applications of AI to worklist prioritization and patient triage, the performance-boosting effects of AI as a second reader, and the use of AI to facilitate complex quantifications. We also introduce prominent examples of recent AI applications, such as tuberculosis screening in resource-constrained environments, the detection of lung cancer with screening CT, and the diagnosis of COVID-19. We also provide examples of prognostic predictions and new discoveries beyond existing clinical practices.

Background

Artificial intelligence (AI) has shown promising performance for thoracic diseases, particularly in the field of thoracic radiology. However, it has not yet been established how AI-based image analysis systems can help physicians in clinical practice.

Methods

This review included peer-reviewed research articles on AI in the thorax published in English between 2015 and 2021.

Conclusions

With advances in technology and appropriate preparation of physicians, AI could address various clinical problems that have not been solved due to a lack of clinical resources or technological limitations.

Keywords

Artificial intelligence (AI); deep learning (DL); computer aided diagnosis (CAD); thoracic radiology; pulmonary medicine

Improved cost-sensitive multikernel learning support vector machine algorithm based on particle swarm optimization in pulmonary nodule recognition

In the lung computer-aided detection (Lung CAD) system, the region of interest (ROI) of lung nodules has more false positives, making the imbalance between positive and negative (true positive and false positive) samples more likely to lead to misclassification of true positive nodules, a cost-sensitive multikernel learning support vector machine (CS-MKL-SVM) algorithm is proposed. Different penalty coefficients are assigned to positive and negative samples, so that the model can better learn the features of true positive nodules and improve the classification effect. To further improve the detection rate of pulmonary nodules and overall recognition accuracy, a score function named F-new based on the harmonic mean of accuracy (ACC) and sensitivity (SEN) is proposed as a fitness function for subsequent particle swarm optimization (PSO) parameter optimization, and a feasibility analysis of this function is performed. Compared with the fitness function that considers only accuracy or sensitivity, both the detection rate and the recognition accuracy of pulmonary nodules can be improved by this new algorithm. Compared with the grid search algorithm, using PSO for parameter search can reduce the model training time by nearly 20 times and achieve rapid parameter optimization. The maximum F-new obtained on the test set is 0.9357 for the proposed algorithm. When the maximum value of F-new is achieved, the corresponding recognition ACC is 91%, and SEN is 96.3%. Compared with the radial basis function in the single kernel, the F-new of the algorithm in this paper is 2.16% higher, ACC is 1.00% higher and SEN is equal. Compared with the polynomial kernel function in the single kernel, the F-new of the algorithm is 3.64% higher, ACC is 1.00% higher and SEN is 7.41% higher. The experimental results show that the F-new, ACC and SEN of the proposed algorithm is the best among them, and the results obtained by using multikernel function combined with F-new index are better than the single kernel function. Compared with the MKL-SVM algorithm of grid search, the ACC of the algorithm in this paper is reduced by 1%, and the results are equal to those of the MKL-SVM algorithm based on PSO only. Compared with the above two algorithms, SEN is increased by 3.71% and 7.41%, respectively. Therefore, it can be seen that the cost sensitive method can effectively reduce the missed detection of nodules, and the availability of the new algorithm can be further verified.

Computer-aided diagnosis system versus conventional reading system in low-dose (< 2 mSv) computed tomography: comparative study for patients at risk of lung cancer

BACKGROUND

Computer-aided diagnosis in low-dose (≤ 3 mSv) computed tomography (CT) is a potential screening tool for lung nodules, with quality interpretation and less inter-observer variability among readers. Therefore, we aimed to determine the screening potential of CT using a radiation dose that does not exceed 2 mSv.

OBJECTIVE

We aimed to compare the diagnostic parameters of low-dose (< 2 mSv) CT interpretation results using a computer-aided diagnosis system for lung cancer screening with those of a conventional reading system used by radiologists.

DESIGN AND SETTING

We conducted a comparative study of chest CT images for lung cancer screening at three private institutions.

METHODS

A database of low-dose (< 2 mSv) chest CT images of patients at risk of lung cancer was viewed with the conventional reading system (301 patients and 226 nodules) or computer-aided diagnosis system without any subsequent radiologist review (944 patients and 1,048 nodules).

RESULTS

The numbers of detected and solid nodules per patient (both P < 0.0001) were higher using the computer-aided diagnosis system than those using the conventional reading system. The nodule size was reported as the maximum size in any plane in the computer-aided diagnosis system. Higher numbers of patients (102 [11%] versus 20 [7%], P = 0.0345) and nodules (154 [15%] versus 17 [8%], P = 0.0035) were diagnosed with cancer using the computer-aided diagnosis system.

CONCLUSIONS

The computer-aided diagnosis system facilitates the diagnosis of cancerous nodules, especially solid nodules, in low-dose (< 2 mSv) CT among patients at risk for lung cancer.

Thoracic and Extrathoracic Malignancies in Lung Cancer Screening Patients With Histories of Malignancy

PURPOSE

The objective of this study was to assess whether a history of malignancy affects the incidence of extrathoracic malignancies and lung cancer in patients undergoing CT lung cancer screening (LCS).

METHODS

All patients who underwent a LCS CT between June 2014 and August 2018 in a single health care system were included. History of prior nonskin malignancy was extracted from billing records. Subsequent diagnoses of malignancy were extracted from clinical pathology reports. Risk for subsequent malignancy was compared between patients with and those without prior malignancy and evaluated using multivariate logistic regression including age and history of malignancy.

RESULTS

A total of 5,835 LCS CT studies were included, and 1,243 (21%) were performed on patients with diagnoses of malignancy before CT. For the 4,592 scans performed on patients without histories of malignancy, 87 patients (1.9%) were diagnosed with lung cancer and 68 (1.5%) were diagnosed with nonlung malignancies in the following year. Among patients with histories of malignancy, 17 (1.4%) were diagnosed with lung cancer, and 25 (2%) were diagnosed with nonlung malignancies. Logistic regression for subsequent diagnosis of malignancy (including lung cancer) demonstrated age to be predictive, with an odds ratio of 1.6 per decade (P < .0001); history of malignancy was not predictive of subsequent malignancy (P = .50).

CONCLUSIONS

Patients with histories of malignancy referred for LCS have a similar risk for developing lung cancers and extrathoracic malignancies as patients without histories of malignancy. Patients with histories of malignancy who are believed by their referring providers to be at low risk for metastasis should not be excluded from LCS.

Early detection of lung cancer in Czech high-risk asymptomatic individuals (ELEGANCE): A study protocol

BACKGROUND

Lung cancer screening in high-risk population increases the proportion of patients diagnosed at a resectable stage.

AIMS

To optimize the selection criteria and quality indicators for lung cancer screening by low-dose CT (LDCT) in the Czech population of high-risk individuals. To compare the influence of screening on the stage of lung cancer at the time of the diagnosis with the stage distribution in an unscreened population. To estimate the impact on life-years lost according to the stage-specific cancer survival and stage distribution in the screened population. To calculate the cost-effectiveness of the screening program.

METHODS

Based on the evidence from large national trials - the National Lung Screening Trial in the USA (NLST), the NELSON study, the recent recommendations of the Fleischner society, the American College of Radiology, and I-ELCAP action group, we developed a protocol for a single-arm prospective study in the Czech Republic for the screening of high-risk asymptomatic individuals. The study commenced in August 2020.

RESULTS

The inclusion criteria are: age 55 to 74 years; smoking: ≥30 pack-years; smoker or ex-smoker <15 years; performance status (0-1). The screening timepoints are at baseline and 1 year. The LDCT acquisition has a target CTDIvol ≤0.5mGy and effective dose ≤0.2mSv for a standard-size patient. The interpretation of findings is primarily based on nodule volumetry, volume doubling time (and related risk of malignancy). The management includes follow-up LDCT, contrast enhanced CT, PET/CT, tissue sampling. The primary outcome is the number of cancers detected at a resectable stage, secondary outcomes include the average cost per diagnosis of lung cancer, the number, cost, complications of secondary examinations, and the number of potentially important secondary findings.

CONCLUSIONS

A study protocol for early detection of lung cancer in Czech high-risk asymptomatic individuals (ELEGANCE) study using LDCT has been described.

Implementation of low-dose CT screening in two different health care systems: Mount Sinai Healthcare System and Phoenix VA Health Care System

Implementation of lung screening (LS) programs is challenging even among health care organizations that have the motivation, the resources, and more importantly, the goal of providing for life-saving early detection, diagnosis, and treatment of lung cancer. We provide a case study of LS implementation in different healthcare systems, at the Mount Sinai Healthcare System (MSHS) in New York City, and at the Phoenix Veterans Affairs Health Care System (PVAHCS) in Phoenix, Arizona. This will illustrate the commonalities and differences of the LS implementation process in two very different health care systems in very different parts of the United States. Underlying the successful implementation of these LS programs was the use of a comprehensive management system, the Early Lung Cancer Action Program (ELCAP) Management System^TM. The collaboration between MSHS and PVAHCS over the past decade led to the ELCAP Management System^TM being gifted by the Early Diagnosis and Treatment Research Foundation to the PVAHCS, to develop a “VA-ELCAP” version. While there remain challenges and opportunities to continue improving LS and its implementation, there is an increasing realization that most patients who are diagnosed with lung cancer as a result of annual LS can be cured, and that of all the possible risks associated with LS, the greater risk of all is for heavy cigarette smokers not to be screened. We identified 10 critical components in implementing a LS program. We provided the details of each of these components for the two healthcare systems. Most importantly, is that continual re-evaluation of the screening program is needed based on the ongoing quality assurance program and database of the actual screenings. At minimum, there should be an annual review and updating. As early diagnosis of lung cancer must be followed by optimal treatment to be effective, treatment advances for small, early lung cancers diagnosed as a result of screening also need to be assessed and incorporated into the entire screening and treatment program.

Lung Cancer Screening by Low-Dose Computed Tomography - Part 1: Expected Benefits, Possible Harms, and Criteria for Eligibility and Population Targeting

BACKGROUND

 Trials in the USA and Europe have convincingly demonstrated the efficacy of screening by low-dose computed tomography (LDCT) as a means to lower lung cancer mortality, but also document potential harms related to radiation, psychosocial stress, and invasive examinations triggered by false-positive screening tests and overdiagnosis. To ensure that benefits (lung cancer deaths averted; life years gained) outweigh the risk of harm, lung cancer screening should be targeted exclusively to individuals who have an elevated risk of lung cancer, plus sufficient residual life expectancy.

METHODS AND CONCLUSIONS

 Overall, randomized screening trials show an approximate 20 % reduction in lung cancer mortality by LDCT screening. In view of declining residual life expectancy, especially among continuing long-term smokers, risk of being over-diagnosed is likely to increase rapidly above the age of 75. In contrast, before age 50, the incidence of LC may be generally too low for screening to provide a positive balance of benefits to harms and financial costs. Concise criteria as used in the NLST or NELSON trials may provide a basic guideline for screening eligibility. An alternative would be the use of risk prediction models based on smoking history, sex, and age as a continuous risk factor. Compared to concise criteria, such models have been found to identify a 10 % to 20 % larger number of LC patients for an equivalent number of individuals to be screened, and additionally may help provide security that screening participants will all have a high-enough LC risk to balance out harm potentially caused by radiation or false-positive screening tests.

KEY POINTS

  · LDCT screening can significantly reduce lung cancer mortality. · Screening until the age of 80 was shown to be efficient in terms of cancer deaths averted; in terms of LYG relative to overdiagnosis, stopping at a younger age (e. g. 75) may have greater efficiency. · Risk models may improve the overall net benefit of lung cancer screening.

CITATION FORMAT

· Kaaks R, Delorme S. Lung Cancer Screening by Low-Dose Computed Tomography - Part 1: Expected Benefits, Possible Harms, and Criteria for Eligibility and Population Targeting. Fortschr Röntgenstr 2021; 193: 527 - 536.

Quality of smoking cessation advice in guidelines of tobacco-related diseases: An updated systematic review

Tobacco smoking is a major risk factor for a wide range of diseases, and smoking cessation significantly reduces these risks. Clinical guidelines for diseases associated with smoking should therefore include guidance on smoking cessation. This review updated evidence on the proportion of clinical guidelines that do so. We conducted a systematic review investigating clinical guidelines and recommendations developed by UK national or European transnational medical specialty associations and societies between January 2014 and October 2019 on 16 diseases to be at least twice as common among smokers than non-smokers. Outcomes of interest were the reporting of smoking as a risk factor, and the inclusion either of smoking cessation advice or referral to other cessation guidance. We compared our findings with an earlier review of guidelines published between 2000 and 2013. We identified 159 clinical guidelines/recommendations. Over half (51%) made no mention of smoking, while 43% reported smoking as a risk factor for the development of the disease, 31% recommended smoking cessation and 19% provided detailed information on how to deliver smoking cessation support. These proportions were similar to those in our earlier review. Smoking cessation continues to be neglected in clinical management guidance for diseases caused by smoking.

Milestones towards lung cancer screening implementation

The European Society of Radiology (ESR) and European Respiratory Society (ERS) published their joint statement paper on lung cancer screening (LCS), on 12 February 2020. This document joins and completes previous recommendations on LCS with specific emphasis on the analysis of issues encountered in the practical implementation of LCS in the community. Major milestones to enable the most efficient and equal dissemination of LCS are recognised as engagement of all stakeholders (e.g. candidate/participant, general practitioners, up to the specialised LCS facility), quality assurance, and primary prevention in the form of provision of counselling for smoking cessation.

Implementation of the cloud-based computerized interpretation system in a nationwide lung cancer screening with low-dose CT: comparison with the conventional reading system

OBJECTIVES

We aimed to compare the CT interpretation before and after the implementation of a computerized system for lung nodule detection and measurements in a nationwide lung cancer screening program.

METHODS

Our screening program started in April 2017, with 14 participating institutions. Initially, all CTs were interpreted using interpretation systems in each institution and manual nodule measurement (conventional system). A cloud-based CT interpretation system, equipped with semi-automated measurement and CAD (computer-aided detection) for lung nodules (cloud-based system), was implemented during the project. Positive rates and performances for lung cancer diagnosis based on the Lung-RADS version 1.0 were compared between the conventional and cloud-based systems.

RESULTS

A total of 1821 (M:F = 1782:39, mean age 62.7 years, 16 confirmed lung cancers) and 4666 participants (M:F = 4560:106, mean age 62.8 years, 31 confirmed lung cancers) were included in the conventional and cloud-based systems, respectively. Significantly more nodules were detected in the cloud-based system (0.76 vs. 1.07 nodule/participant, p < .001). Positive rate did not differ significantly between the two systems (9.9% vs. 11.0%, p = .211), while their variability across institutions was significantly lower in the cloud-based system (coefficients of variability, 0.519 vs. 0.311, p = .018). The Lung-RADS-based sensitivity (93.8% vs. 93.5%, p = .979) and specificity (90.9% vs. 89.6%, p = .132) did not differ significantly between the two systems.

CONCLUSION

Implementation of CAD and semi-automated measurement for lung nodules in a nationwide lung cancer screening program resulted in increased number of detected nodules and reduced variability in positive rates across institutions.

KEY POINTS

• Computer-aided CT reading detected more lung nodules than radiologists alone in lung cancer screening. • Positive rate in lung cancer screening did not change with computer-aided reading. • Computer-aided CT reading reduced inter-institutional variability in lung cancer screening.

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

OBJECTIVES

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.

METHODS

Patients with a previous history of malignancy, a life expectancy ≥ 5 years 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.

RESULTS

A total of 543 patients were studied (mean age of 66 years). 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.

CONCLUSIONS

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.

KEY POINTS

• 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.

A practical and adaptive approach to lung cancer screening: a review of international evidence and position on CT lung cancer screening in the Singaporean population by the College of Radiologists Singapore

Lung cancer is the leading cause of cancer-related death around the world, being the top cause of cancer-related deaths among men and the second most common cause of cancer-related deaths among women in Singapore. Currently, no screening programme for lung cancer exists in Singapore. Since there is mounting evidence indicating a different epidemiology of lung cancer in Asian countries, including Singapore, compared to the rest of the world, a unique and adaptive approach must be taken for a screening programme to be successful at reducing mortality while maintaining cost-effectiveness and a favourable risk-benefit ratio. This review article promotes the use of low-dose computed tomography of the chest and explores the radiological challenges and future directions.

ERS International Congress, Madrid, 2019: highlights from the Thoracic Oncology Assembly

Lung cancer is a devastating disease affecting hundreds of thousands of patients in Europe. Despite recent advances in treatment, its prognosis remains poor. This is mainly attributed to the late stages that diagnoses are usually established at, consequently excluding curative treatment options. During the 2019 European Respiratory Society International Congress in Madrid, Spain, lung cancer experts presented the most recent aspects of lung cancer early detection with low-dose computed tomography.

Key thoracic oncology highlights from #ERSCongress Madrid 2019https://bit.ly/3dQZtv7

Dependent lesion positioning at CT-guided lung biopsy to reduce risk of pneumothorax

OBJECTIVES

To evaluate the impact of patient positioning during CT-guided lung biopsy on patients' outcomes.

METHODS

In this retrospective, IRB-approved, HIPAA-compliant study, consecutive CT-guided lung biopsies performed on 5/1/2015-12/26/2017 were included. Correlation between incidence of pneumothorax, chest tube placement, pulmonary bleeding with patient, and procedure characteristics was evaluated. Lesion-trachea-table angle (LTTA) was defined as an angle between the lesion, trachea, and horizontal line parallel to the table. Lesion above trachea has a positive LTTA. Univariate and multivariate logistic regression analysis was performed.

RESULTS

A total of 423 biopsies in 409 patients (68 ± 11 years, 231/409, 56% female) were included in the study. Pneumothorax occurred in 83/423 (20%) biopsies with chest tube placed in 11/423 (3%) biopsies. Perilesional bleeding occurred in 194/423 (46%) biopsies and hemoptysis in 20/423 (5%) biopsies. Univariate analysis showed an association of pneumothorax with smaller lesions (p = 0.05), positive LTTA (p = 0.002), and lesions not attached to pleura (p = 0.026) with multivariate analysis showing lesion size and LTTA to be independent risk factors. Univariate analysis showed an association of increased pulmonary bleeding with smaller lesions (p < 0.001), no attachment to the pleura (p < 0.001), needle throw < 16 mm (p = 0.05), and a longer needle path (p < 0.001). Multivariate analysis showed lesion size, a longer needle path, and lesions not attached to the pleura to be independently associated with perilesional bleeding. Risk factors for hemoptysis were longer needle path (p = 0.002), no attachment to the pleura (p = 0.03), and female sex (p = 0.04).

CONCLUSIONS

Interventional radiologists can reduce the pneumothorax risk during the CT-guided biopsy by positioning the biopsy site below the trachea.

KEY POINTS

• Positioning patient with lesion to be below the trachea for the CT-guided lung biopsy results in lower rate of pneumothorax, as compared with the lesion above the trachea. • Positioning patient with lesion to be below the trachea for the CT-guided lung biopsy does not affect rate of procedure-associated pulmonary hemorrhage or hemoptysis.

Attitudes toward tobacco cessation and lung cancer screening in two South African communities

Among men in South Africa, the prevalence of tobacco smoking is as high as 33%. Although smoking is responsible for most lung cancer in South Africa, occupational and environmental exposures contribute greatly to risk. We conducted a tobacco and lung cancer screening needs assessment and administered surveys to adults who smoked >100 cigarettes in their lifetime in Johannesburg (urban) and Kimberley (rural). We compared tobacco use, risk exposure, attitudes toward and knowledge of, and receptivity to cessation and screening, by site. Of 324 smokers, nearly 85% of current smokers had a <30 pack-year history of smoking; 58.7% had tried to stop smoking ≥1 time, and 78.9% wanted to quit. Kimberley smokers more often reported being advised by a healthcare provider to stop smoking (56.5% vs. 37.3%, p=0.001) than smokers in Johannesburg but smokers in Johannesburg were more willing to stop smoking if advised by their doctor (72.9% vs. 41.7%, p<0.001). Findings indicate that tobacco smokers in two geographic areas of South Africa are motivated to stop smoking but receive no healthcare support to do so. Developing high risk criteria for lung cancer screening and creating tobacco cessation infrastructure may reduce tobacco use and decrease lung cancer mortality in South Africa.

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.

Implementation of lung cancer screening at the national level: Polish example

In Poland the national demonstration lung cancer screening program is about to be started in 2019. We share our concerns and discussing most important topics to be resolved while preparing such a program. The decisions made are virtually based on available scientific data and the results of two randomized controlled trials but also on the personal experience gained during the lung cancer screening studies performed in Poland. The most important and comprehensive guidelines and statements, both European and American, have been searched to find an optimal solution adjusted to the Polish national circumstances-as we assume that should be done in each country implementing such a program.

Highlights of thoracic oncology from the 2018 ERS International Congress

Lung cancer is a substantial global burden for patients, healthcare professionals and healthcare systems. Multiple scientific international and national initiatives are tackling the various problems associated with this disease, which is currently the leading cause of cancer-related mortality worldwide. During the European Respiratory Society International Congress 2018 in Paris, France, lung cancer experts gathered to present the most recent aspects of lung cancer care, and discuss the need for joint initiatives and an international lung cancer alliance, aiming to provide high quality, accessible health care. The US experience and American Lung Association/American Thoracic Society implementation guide on lung cancer screening programmes, the key features of optimising and implementing such programmes, the challenges of treatment in the subset of patients where lung cancer is combined with interstitial lung disease, and novel lung cancer biomarkers and immunotherapy were among the most anticipated issues covered during the congress.

Lung cancer is a serious global burden for patients and healthcare systems. Experts from multiple scientific societies gathered during #ERSCongress 2018, to present the most recent aspects on care and stress the need for joint initiatives.http://bit.ly/2VK2S4P

LUCSO-1-French pilot study of LUng Cancer Screening with low-dose computed tomography in a smokers population exposed to Occupational lung carcinogens: study protocol

INTRODUCTION

Guidelines concerning the follow-up of subjects occupationally exposed to lung carcinogens, published in France in 2015, recommended the setting up of a trial of low-dose chest CT lung cancer screening in subjects at high risk of lung cancer.

OBJECTIVE

To evaluate the organisation of low-dose chest CT lung cancer screening in subjects occupationally exposed to lung carcinogens and at high risk of lung cancer.

METHODS AND ANALYSIS

This trial will be conducted in eight French departments by six specialised reference centres (SRCs) in occupational health. In view of the exploratory nature of this trial, it is proposed to test initially the feasibility and acceptability over the first 2 years in only two SRCs then in four other SRCs to evaluate the organisation. The target population is current or former smokers with more than 30 pack-years (who have quit smoking for less than 15 years), currently or previously exposed to International Agency for Research on Cancer group 1 lung carcinogens, and between the ages of 55 and 74 years. The trial will be conducted in the following steps: (1) identification of subjects by a screening invitation letter; (2) evaluation of occupational exposure to lung carcinogens; (3) evaluation of the lung cancer risk level and verification of eligibility; (4) screening procedure: annual chest CT scans performed by specialised centres and (5) follow-up of CT scan abnormalities.

ETHICS AND DISSEMINATION

This protocol study has been approved by the French Committee for the Protection of Persons. The results from this study will be submitted to peer-reviewed journals and reported at suitable national and international meetings.

TRIAL REGISTRATION NUMBER

NCT03562052; Pre-results.

Hybrid control algorithm for flexible needle steering: Demonstration in phantom and human cadaver

Needles are commonly used in the clinic for percutaneous procedures. The outcome of such procedures heavily depends on accurate placement of the needle. There are two main challenges to achieve high accuracy: First, aligning the needle with the targeted lesion, and second, compensating for the deflection of the needle in the tissue. In order to address these challenges, scientists have developed several robotic setups for needle steering. However, the subject is still under research and reliable implementations which can be used in clinical practice are not yet available. In this paper, we have taken some steps in order to bring needle steering closer to practice. A new hybrid control algorithm is developed, which enables us to control a flexible needle by combing base-manipulation and beveled-tip steering methods. A pre-operative path planner is developed which considers the clinical requirements. The proposed method is tested in the lung of a fresh-frozen human cadaver. The work-flow of the experiments are similar to the current clinical practice. Three experimental cases are used to evaluate the proposed steering algorithm. Experimental Case I shows that using the proposed steering algorithm controllability of the needle is increased. In Case II and Case III, the needle is steered in a gelatin phantom and a human cadaver, respectively. The targeting accuracy of 1.35±0.49mm in gelatin phantom and 1.97±0.89mm in cadave is achieved. A feasibility study is performed, in which a fine needle aspiration (FNA) needle is steered in the lungs of a human cadaver under computed tomography guidance. The targeting error for the feasibility study is 2.89±0.22mm. The results suggest that such a robotic system can be beneficial for clinical use and the patient receives less x-ray radiation.

Impact of automatically detected motion artifacts on coronary calcium scoring in chest computed tomography

The amount of coronary artery calcification (CAC) quantified in computed tomography (CT) scans enables prediction of cardiovascular disease (CVD) risk. However, interscan variability of CAC quantification is high, especially in scans made without ECG synchronization. We propose a method for automatic detection of CACs that are severely affected by cardiac motion. Subsequently, we evaluate the impact of such CACs on CAC quantification and CVD risk determination. This study includes 1000 baseline and 585 one-year follow-up low-dose chest CTs from the National Lung Screening Trial. About 415 baseline scans are used to train and evaluate a convolutional neural network that identifies observer determined CACs affected by severe motion artifacts. Therefore, 585 paired scans acquired at baseline and follow-up were used to evaluate the impact of severe motion artifacts on CAC quantification and risk categorization. Based on the CAC amount, the scans were categorized into four standard CVD risk categories. The method identified CACs affected by severe motion artifacts with 85.2% accuracy. Moreover, reproducibility of CAC scores in scan pairs is higher in scans containing mostly CACs not affected by severe cardiac motion. Hence, the proposed method enables identification of scans affected by severe cardiac motion, where CAC quantification may not be reproducible.

Sleep disordered breathing and nocturnal hypoxemia are very prevalent in a lung cancer screening population and may condition lung cancer screening findings: results of the prospective Sleep Apnea In Lung Cancer Screening (SAILS) study

OBJECTIVE

Obstructive sleep apnea (OSA) can influence the appearance and proliferation of some tumors. The Sleep Apnea In Lung Cancer Screening (SAILS) study (NCT02764866) evaluated the prevalence of OSA and nocturnal hypoxemia in a high-risk population enrolled in a lung cancer screening program.

METHODS

This was a prospective study of the prevalence of OSA in a lung cancer screening program. Subjects met the National Lung Screening Trial (NLST) age and smoking criteria (age 55-75 years; pack-years >30). Participants in the study were offered annual screening with low-dose computed tomography (LDCT) and pulmonary function testing, as well as home sleep apnea testing (HSAT) and a sleep-specific questionnaire. Sleep study-related variables, symptoms, and epidemiologic data were recorded.

RESULTS

HSAT was offered to 279 subjects enrolled in our lung cancer screening program. HSAT results were available for 236 participants (mean age 63.6 years; mean tobacco exposure: 45 pack-years), of whom 59% were male and 53% were active smokers. Emphysema (74%) and chronic obstructive pulmonary disease (COPD) (62%) were common and in most cases mild in severity. OSA, including moderate to severe disease, was very common in this patient population. AHI distributions were as follows: AHI <5 (22.5%); 5-15 (36.4%); 15-30 (23.3%); and >30 (17.8%). Nocturnal hypoxemia (T90) (p = 0.003), diffusing capacity for carbon monoxide (DLCO) (p = 0.01), tobacco exposure (p = 0.024), and COPD (p = 0.023) were associated with OSA severity. Positive screening findings (nodules ≥6 mm) were associated with nocturnal hypoxemia on multivariate analysis adjusted for confounders (OR = 2.6, 95% CI = 1.12-6.09, p = 0.027).

CONCLUSION

Moderate to severe OSA is very prevalent in patients enrolled in a lung cancer screening program. Nocturnal hypoxemia more than doubles the risk of positive screening findings.

Telehealth for patients with chronic obstructive pulmonary disease (COPD): a systematic review and meta-analysis protocol

INTRODUCTION

Chronic obstructive pulmonary disease (COPD) is a highly prevalent chronic disease characterised by persistent respiratory symptoms. A focus of COPD interventional studies is directed towards prevention of exacerbations leading to hospital readmissions. Telehealth as a method of remote patient monitoring and care delivery may be implemented to reduce hospital readmissions and improve self-management of disease. Prior reviews have not systematically assessed the efficacies of various telehealth functionalities in patients with COPD at different stages of disease severity. We aim to evaluate which COPD telehealth interventions, classified by their functionalities, are most effective in improving patient with COPD management measured by both clinical and resource utilisation outcomes.

METHODS AND ANALYSIS

We will conduct a systematic review which will include randomised controlled trials comparing the efficacy of telehealth interventions versus standard care in patients with COPD with confirmed disease severity based on forced expiratory volume(%) levels. An electronic search strategy will be used to identify trials published since 2000 in MEDLINE, EMBASE, the Cochrane Central Register of Controlled Trials, CINHAL. Telehealth is described as remote monitoring and delivery of care where patient data/clinical information is routinely or continuously collected and/or processed, presented to the patient and transferred to a clinical care institution for feedback, triage and intervention by a clinical specialist. Two authors will independently screen articles for inclusion, assess risk of bias and extract data. We will merge studies into a meta-analysis if the interventions, technologies, participants and underlying clinical questions are homogeneous enough. We will use a random-effects model, as we expect some heterogeneity between interventions. In cases where a meta-analysis is not possible, we will synthesise findings narratively. We will assess the quality of the evidence for the main outcomes using GRADE.

ETHICS AND DISSEMINATION

Research ethics approval is not required. The findings will be disseminated through publication in a peer-reviewed journal.

PROSPERO REGISTRATION NUMBER

CRD42018083671.

Challenges in Lung Cancer Screening in Latin America

Lung cancer is the deadliest cancer worldwide and is of particular concern for Latin America. Its rising incidence in this area of the world poses myriad challenges for the region's economies, which are already struggling with limited resources to meet the health care needs of low- and middle-income populations. In this environment, we are concerned that regional governments are relatively unaware of the pressing need to implement effective strategies for the near future. Low-dose chest computed tomography (LDCT) for screening, and routine use of minimally invasive techniques for diagnosis and staging remain uncommon. According to results of the National Lung Screening Trial, LDCT lung cancer screening provided a 20% relative reduction in mortality rates among at-risk individuals. Nevertheless, this issue is still a matter of debate, particularly in developing countries, and it is not fully embraced in developing countries. The aim of this article is to provide an overview of what the standard of care is for lung cancer computed tomography screening around the world and to aid understanding of the challenges and potential solutions that can help with the implementation of LDCT in Latin America.

Novel high-resolution computed tomography-based radiomic classifier for screen-identified pulmonary nodules in the National Lung Screening Trial

Purpose

Optimization of the clinical management of screen-detected lung nodules is needed to avoid unnecessary diagnostic interventions. Herein we demonstrate the potential value of a novel radiomics-based approach for the classification of screen-detected indeterminate nodules.

Material and methods

Independent quantitative variables assessing various radiologic nodule features such as sphericity, flatness, elongation, spiculation, lobulation and curvature were developed from the NLST dataset using 726 indeterminate nodules (all ≥ 7 mm, benign, n = 318 and malignant, n = 408). Multivariate analysis was performed using least absolute shrinkage and selection operator (LASSO) method for variable selection and regularization in order to enhance the prediction accuracy and interpretability of the multivariate model. The bootstrapping method was then applied for the internal validation and the optimism-corrected AUC was reported for the final model.

Results

Eight of the originally considered 57 quantitative radiologic features were selected by LASSO multivariate modeling. These 8 features include variables capturing Location: vertical location (Offset carina centroid z), Size: volume estimate (Minimum enclosing brick), Shape: flatness, Density: texture analysis (Score Indicative of Lesion/Lung Aggression/Abnormality (SILA) texture), and surface characteristics: surface complexity (Maximum shape index and Average shape index), and estimates of surface curvature (Average positive mean curvature and Minimum mean curvature), all with P<0.01. The optimism-corrected AUC for these 8 features is 0.939.

Conclusions

Our novel radiomic LDCT-based approach for indeterminate screen-detected nodule characterization appears extremely promising however independent external validation is needed.

The Effects of Iodine Attenuation on Pulmonary Nodule Volumetry using Novel Dual-Layer Computed Tomography Reconstructions

OBJECTIVES

To assess the effect of iodine attenuation on pulmonary nodule volumetry using virtual non-contrast (VNC) and mono-energetic reconstructions.

METHODS

A consecutive series of patients who underwent a contrast-enhanced chest CT scan were included. Images were acquired on a novel dual-layer spectral CT system. Conventional reconstructions as well as VNC and mono-energetic images at different keV levels were used for nodule volumetry.

RESULTS

Twenty-four patients with a total of 63 nodules were included. Conventional reconstructions showed a median (interquartile range) volume and diameter of 174 (87 - 253) mm3 and 6.9 (5.4 - 9.9) mm, respectively. VNC reconstructions resulted in a significant volume reduction of 5.5% (2.6 - 11.2%; p<0.001). Mono-energetic reconstructions showed a correlation between nodule attenuation and nodule volume (Spearman correlation 0.77, (0.49 - 0.94)). Lowering the keV resulted in increased volumes while higher keV levels resulted in decreased pulmonary nodule volumes compared to conventional CT.

CONCLUSIONS

Novel dual-layer spectral CT offers the possibility to reconstruct VNC and mono-energetic images. Those reconstructions show that higher pulmonary nodule attenuation results in larger nodule volumes. This may explain the reported underestimation in nodule volume on non-contrast enhanced compared to contrast-enhanced acquisitions.

KEY POINTS

• Pulmonary nodule volumes were measured on virtual non-contrast and mono-energetic reconstructions • Mono-energetic reconstructions showed that higher attenuation results in larger volumes • This may explain the reported nodule volume underestimation on non-contrast enhanced CT • Mostly metastatic pulmonary nodules were evaluated, results might differ for benign nodules.

Quality assurance and quantitative imaging biomarkers in low-dose CT lung cancer screening

After years of assessment through controlled clinical trials, low-dose CT screening for lung cancer is becoming part of clinical practice. As with any cancer screening test, those undergoing lung cancer screening are not being evaluated for concerning signs or symptoms, but are generally in good health and proactively trying to prevent premature death. Given the resultant obligation to achieve the screening aim of early diagnosis while also minimizing the potential for morbidity from workup of indeterminate but ultimately benign screening abnormalities, careful implementation of screening with conformance to currently recognized best practices and a focus on quality assurance is essential. In this review, we address the importance of each component of the screening process to optimize the effectiveness of CT screening, discussing options for quality assurance at each step. We also discuss the potential added advantages, quality assurance requirements and current status of quantitative imaging biomarkers related to lung cancer screening. Finally, we highlight suggestions for improvements and needs for further evidence in evaluating the performance of CT screening as it transitions from the research trial setting into daily clinical practice.

[Lung cancer screening with thoracic X‑ray and CT : Current situation]

CLINICAL/METHODICAL ISSUE

Attempts at the early detection of lung cancer using imaging methods began as far back as the 1950s.

STANDARD RADIOLOGICAL METHODS

Several studies attempted to demonstrate a reduction of lung cancer mortality by chest radiography screening but all were unsuccessful.

METHODICAL INNOVATIONS

Even the first small screening studies using computed tomography (CT) could not demonstrate a reduction in lung cancer-specific mortality until in 2011 the results of the largest randomized controlled low-dose CT screening study in the USA (NLST) were published. The NLST results could show a significant 20 % reduction of lung cancer mortality in elderly and heavy smokers using CT.

PERFORMANCE

Confirmation of the NLST results are urgently needed so that the data of the largest European study (NELSON) are eagerly awaited.

ACHIEVEMENTS

Pooled with the data from several smaller European studies these results will provide important information and evidence for the establishment of future CT screening programs in Europe.

PRACTICAL RECOMMENDATIONS

Randomized controlled trials are the basis of evidence-based medicine; therefore, the positive results of the methodologically very good NLST study cannot be ignored, even if it is the only such study completed so far with highly convincing conclusions. The NLST results clearly demonstrate that positive effects for the health of the population can only be expected if the processes are clearly defined and the quality is assured.

Implementation of lung cancer CT screening in the Nordic countries

INTRODUCTION

We review the current knowledge of CT screening for lung cancer and present an expert-based, joint protocol for the proper implementation of screening in the Nordic countries.

MATERIALS AND METHODS

Experts representing all the Nordic countries performed literature review and concensus for a joint protocol for lung cancer screening.

RESULTS AND DISCUSSION

Areas of concern and caution are presented and discussed. We suggest to perform CT screening pilot studies in the Nordic countries in order to gain experience and develop specific and safe protocols for the implementation of such a program.

Trade-off between benefits, harms and economic efficiency of low-dose CT lung cancer screening: a microsimulation analysis of nodule management strategies in a population-based setting

BACKGROUND

In lung cancer screening, a nodule management protocol describes nodule assessment and thresholds for nodule size and growth rate to identify patients who require immediate diagnostic evaluation or additional imaging exams. The Netherlands-Leuvens Screening Trial and the National Lung Screening Trial used different selection criteria and nodule management protocols. Several modelling studies have reported variations in screening outcomes and cost-effectiveness across selection criteria and screening intervals; however, the effect of variations in the nodule management protocol remains uncertain. This study evaluated the effects of the eligibility criteria and nodule management protocols on the benefits, harms and cost-effectiveness of lung screening scenarios in a population-based setting in Germany.

METHODS

We developed a modular microsimulation model: a biological module simulated individual histories of lung cancer development from carcinogenesis onset to death; a screening module simulated patient selection, screening-detection, nodule management protocols, diagnostic evaluation and screening outcomes. Benefits included mortality reduction, life years gained and averted lung cancer deaths. Harms were costs, false positives and overdiagnosis. The comparator was no screening. The evaluated 76 screening scenarios included variations in selection criteria and thresholds for nodule size and growth rate.

RESULTS

Five years of annual screening resulted in a 9.7-12.8% lung cancer mortality reduction in the screened population. The efficient scenarios included volumetric assessment of nodule size, a threshold for a volume of 300 mm³ and a threshold for a volume doubling time of 400 days. Assessment of volume doubling time is essential for reducing overdiagnosis and false positives. Incremental cost-effectiveness ratios of the efficient scenarios were 16,754-23,847 euro per life year gained and 155,287-285,630 euro per averted lung cancer death.

CONCLUSIONS

Lung cancer screening can be cost-effective in Germany. Along with the eligibility criteria, the nodule management protocol influences screening performance and cost-effectiveness. Definition of the thresholds for nodule size and nodule growth in the nodule management protocol should be considered in detail when defining optimal screening strategies.