Fleischner Society Guidelines Research Articles

Centrilobular emphysema and airway dysanapsis: factors associated with low respiratory function in younger smokers.

Low respiratory function in young adulthood is one of the important factors in the trajectory leading to the future development of COPD, but its morphological characteristics are not well characterised. We retrospectively enrolled 172 subjects aged 40-49 years with ≥10 pack-years smoking history who underwent lung cancer screening by computed tomography (CT) and spirometry at two Japanese hospitals. Emphysema was visually assessed according to the Fleischner Society guidelines and classified into two types: centrilobular emphysema (CLE) and paraseptal emphysema (PSE). Airway dysanapsis was assessed with the airway/lung ratio (ALR), which was calculated by the geometric mean of the lumen diameters of the 14 branching segments divided by the cube root of total lung volume on a CT scan. Among the subjects, CLE and PSE were observed in 20.9% and 30.8%, respectively. The mean ALR was 0.04 and did not differ between those with and without each type of emphysema. Multivariable regression analysis models adjusted for age, sex, body mass index and smoking status indicated that CLE and a low ALR were independently associated with lower forced expiratory volume in 1 s (FEV1)/forced vital capacity (estimate -1.64 (95% CI -2.68- -0.60) and 6.73 (95% CI 4.24-9.24), respectively) and FEV1 % pred (estimate -2.81 (95% CI -5.10- -0.52) and 10.9 (95% CI 5.36-16.4), respectively). CLE and airway dysanapsis on CT were independently associated with low respiratory function in younger smokers.

Limitations of GPT-3.5 and GPT-4 in Applying Fleischner Society Guidelines to Incidental Lung Nodules.

Purpose: To evaluate the accuracy of GPT-3.5, GPT-4, and a fine-tuned GPT-3.5 model in applying Fleischner Society recommendations to lung nodules. Methods: We generated 10 lung nodule descriptions for each of the 12 nodule categories from the Fleischner Society guidelines, incorporating them into a single fictitious report (n = 120). GPT-3.5 and GPT-4 were prompted to make follow-up recommendations based on the reports. We then incorporated the full guidelines into the prompts and re-submitted them. Finally, we re-submitted the prompts to a fine-tuned GPT-3.5 model. Results were analyzed using binary accuracy analysis in R. Results: GPT-3.5 accuracy in applying Fleischner Society guidelines was 0.058 (95% CI: 0.02, 0.12). GPT-4 accuracy was improved at 0.15 (95% CI: 0.09, 0.23; P = .02 for accuracy comparison). In recommending PET-CT and/or biopsy, both GPT-3.5 and GPT-4 had an F-score of 0.00. After explicitly including the Fleischner Society guidelines in the prompt, GPT-3.5 and GPT-4 significantly improved their accuracy to 0.42 (95% CI: 0.33, 0.51; P < .001) and to 0.66 (95% CI: 0.57, 0.74; P < .001), respectively. GPT-4 remained significantly better than GPT-3.5 (P < .001). The fine-tuned GPT-3.5 model accuracy was 0.46 (95% CI: 0.37, 0.55), not different from the GPT-3.5 model with guidelines included (P = .53). Conclusion: GPT-3.5 and GPT-4 performed poorly in applying widely known guidelines and never correctly recommended biopsy. Flawed knowledge and reasoning both contributed to their poor performance. While GPT-4 was more accurate than GPT-3.5, its inaccuracy rate was unacceptable for clinical practice. These results underscore the limitations of large language models for knowledge and reasoning-based tasks.

Solitary Pulmonary Nodule: Is It Benign or Malignant?

Solitary pulmonary nodules (SPN) are round-shaped opacities with or without firm borders and ≤3 cm in diameter. 40% of solitary pulmonary nodules in high-risk populations are malignant and &gt;10 mm in diameter. With the high incidence of pulmonary cancer, diagnosing pulmonary nodules is essential for clinicians. This review aims to discuss more solitary pulmonary nodules based on multiple recommendations for diagnosis and management. Malignancy probability assessment is the first step in evaluating each patient with new pulmonary nodules, as it significantly affects the prognosis of the disease. The assessment depends on the risk factors present in the patient, which are cigarettes, age, history of cancer, and family history. Radiological evaluation is the second phase in pulmonary nodule evaluation. Predictors of malignant nodules that should be assessed are nodule size, growth rate, nodule morphology, location, and enhancement. Many guidelines have been published regarding treating solitary pulmonary nodules, including the Fleischner Society, ACCP, and BTS guidelines.

Radiomics as a non-invasive adjunct to Chest CT in distinguishing benign and malignant lung nodules

In an observational study conducted from 2016 to 2021, we assessed the utility of radiomics in differentiating between benign and malignant lung nodules detected on computed tomography (CT) scans. Patients in whom a final diagnosis regarding the lung nodules was available according to histopathology and/or 2017 Fleischner Society guidelines were included. The radiomics workflow included lesion segmentation, region of interest (ROI) definition, pre-processing, and feature extraction. Employing random forest feature selection, we identified ten important radiomic features for distinguishing between benign and malignant nodules. Among the classifiers tested, the Decision Tree model demonstrated superior performance, achieving 79% accuracy, 75% sensitivity, 85% specificity, 82% precision, and 90% F1 score. The implementation of the XGBoost algorithm further enhanced these results, yielding 89% accuracy, 89% sensitivity, 89% precision, and an F1 score of 89%, alongside a specificity of 85%. Our findings highlight tumor texture as the primary predictor of malignancy, emphasizing the importance of texture-based features in computational oncology. Thus, our study establishes radiomics as a powerful, non-invasive adjunct to CT scans in the differentiation of lung nodules, with significant implications for clinical decision-making, especially for indeterminate nodules, and the enhancement of diagnostic and predictive accuracy in this clinical context.

Lung Cancer Screening: Low-Dose Thoracic Computed Tomography Performed in a High-Risk Portuguese Population.

The Urgeiriça mines were once the main uranium producer in Portugal. The aim of this study was to estimate the benefit of low-dose chest computed tomography (LDCT) for lung cancer screening in former miners that were considered as being at high-risk. A subgroup of former miners of the Uranium National Company exposed to uranium and with a smoking load greater than 20 pack-years, agreed to perform a LDCT. The Fleischner Society Guidelines were used to classify the nodules and establish follow-up. Initially, 265 former employees of the Uranium National Company were included. The mean time of employment was 15 (0 - 45) years. The non-smokers represented 50.9% and 30.2% were ever smokers; the remaining chose not to respond. One diagnosis of lung cancer was initially made. In the second phase, a subgroup of 66 former miner underwent a LDCT, 37 of whom presented pulmonary nodules. Most computed tomography (CT) scans revealed one single nodule (n = 13) and the mean size was 5 (1 - 16) mm. A suspicious 16 mm spiculated nodule was evaluated with PET/CT, and percutaneous and surgical biopsies, ultimately revealing a benign lesion. The data highlights the importance of lung cancer screening in high-risk populations. This was, to the best of our knowledge, the first study performed in Portugal and can act as a bridge towards a wider implementation in the country.

Interstitial lung abnormalities in a large clinical lung cancer screening cohort: association with mortality and ILD diagnosis

BackgroundInterstitial lung abnormalities (ILA) are CT findings suggestive of interstitial lung disease in individuals without a prior diagnosis or suspicion of ILD. Previous studies have demonstrated that ILA are associated with clinically significant outcomes including mortality. The aim of this study was to determine the prevalence of ILA in a large CT lung cancer screening program and the association with clinically significant outcomes including mortality, hospitalizations, cancer and ILD diagnosis.MethodsThis was a retrospective study of individuals enrolled in a CT lung cancer screening program from 2012 to 2014. Baseline and longitudinal CT scans were scored for ILA per Fleischner Society guidelines. The primary analyses examined the association between baseline ILA and mortality, all-cause hospitalization, and incidence of lung cancer. Kaplan–Meier plots were generated to visualize the associations between ILA and lung cancer and all-cause mortality. Cox regression proportional hazards models were used to test for this association in both univariate and multivariable models.Results1699 subjects met inclusion criteria. 41 (2.4%) had ILA and 101 (5.9%) had indeterminate ILA on baseline CTs. ILD was diagnosed in 10 (24.4%) of 41 with ILA on baseline CT with a mean time from baseline CT to diagnosis of 4.47 ± 2.72 years. On multivariable modeling, the presence of ILA remained a significant predictor of death, HR 3.87 (2.07, 7.21; p < 0.001) when adjusted for age, sex, BMI, pack years and active smoking, but not of lung cancer and all-cause hospital admission. Approximately 50% with baseline ILA had progression on the longitudinal scan.ConclusionsILA identified on baseline lung cancer screening exams are associated with all-cause mortality. In addition, a significant proportion of patients with ILA are subsequently diagnosed with ILD and have CT progression on longitudinal scans.Trial registration number: ClinicalTrials.gov; No.: NCT04503044.

Benignant and malignant epidemiology among surgical resections for suspicious solitary lung cancer without preoperative tissue diagnosis.

The aim of this study was to describe the epidemiology of patients undergoing diagnostic and/or curative surgical pulmonary resections for lung opacities suspected of being localized primary lung cancers without preoperative tissue confirmation. We performed a single-centre retrospective study of a prospectively implemented institutional database of all patients who underwent pulmonary resection between January 2010 and December 2020. Patients were selected when surgery complied with the Fleischner society guidelines. We performed a multivariable logistic regression to determine the preoperative variables associated with malignancy. Among 1392 patients, 213 (15.3%) had a final diagnosis of benignancy. We quantified futile parenchymal resections in 29 (2.1%) patients defined by an anatomical resection of >2 lung segments for benign lesions that did not modified the clinical management. Compared with patients with malignancies, patients with benignancies were younger (57.5 vs 63.9 years, P < 0.001), had lower preoperative risk profile (thoracoscore 0.4 vs 2.1, P < 0.001), had a higher proportion of wedge resection (50.7% vs 12.2%, P < 0.01) and experienced a lower burden of postoperative complication (Clavien-Dindo IV or V, 0.4% vs 5.6%, P < 0.001). Preoperative independent variables associated with malignancy were (adjusted odd ratio [95% confident interval]) age 1.02 [1.00; 1.04], smoking (year-pack) 1.005 (1.00; 1.01), history of cardiovascular disease 2.06 [1.30; 3.30], history of controlled cancer 2.74 [1.30; 6.88] and clinical N involvement 4.20 [1.11; 37.44]. Futile parenchymal lung resection for suspicious opacities without preoperative tissue diagnosis is rare (2.1%) while surgery for benign lesions represented 15.3% and has a satisfactory safety profile with very low postoperative morbi-mortality.

Fleischner Society Guideline Recommendations for Incidentally Detected Pulmonary Nodules and the Probability of Lung Cancer.

The Fleischner Society aims to limit further evaluations of incidentally detected pulmonary nodules when the probability of lung cancer is <1% and to pursue further evaluations when the probability of lung cancer is ≥1%. To evaluate the internal consistency of guideline goals and recommendations, the authors evaluated stratum-specific recommendations and 2-year probabilities of lung cancer. A retrospective cohort study (2005-2015) was conducted of individuals enrolled in one of two integrated health systems with solid nodules incidentally detected on CT. The 2017 Fleischner Society guidelines were used to define strata on the basis of smoking status and nodule size and number. Lung cancer diagnoses within 2 years of nodule detection were ascertained using cancer registry data. Confidence interval (CI) inspection was used to determine if stratum-specific probabilities of lung cancer were different than 1%. Among 5,444 individuals with incidentally detected lung nodules (median age, 66 years; 54% women; 57% smoked; median nodule size, 5.5 mm; 55% with multiple nodules), 214 (3.9%; 95% CI, 3.4%-4.5%) were diagnosed with lung cancer within 2 years. For 7 of 12 strata (58%), 2,765 patients (51%), and 194 lung cancer cases (91%), there was alignment between Fleischner Society goals and recommendations. Alignment was indeterminate for 5 strata (42%), 2,679 patients (49%), and 20 lung cancer cases (9%) because CIs for the probability of lung cancer spanned 1%. Fleischner Society guideline goals and recommendations align at least half the time. It is uncertain whether alignment of guideline goals and recommendations occurs more often.

Radiographic assessment of small lung nodules: what can we do and what information does it give us?

: The evaluation of small pulmonary nodules is a common and challenging clinical scenario often requiring a multi-disciplinary approach to optimize patient care. Radiographic assessment of pulmonary nodules is an important part of the determination of whether a nodule is malignant or benign which then translates into an intervention or a management strategy. A multimodality radiological approach or longitudinal follow up may be needed based on a combination of the clinical and imaging features at initial presentation. In this article, we illustrate the role of anatomical and functional radiological techniques [chest radiography, computed tomography (CT), magnetic resonance imaging (MRI), positron emission tomography/computed tomography (PET/CT)] in the assessment and characterization of small pulmonary nodules, with an emphasis on chest CT, the workhorse of pulmonary imaging. This discussion is framed in the context of how imaging fits into current international guidelines on pulmonary nodule assessment, with an emphasis on both the Fleischner society and British Thoracic Society (BTS) guidelines, including the application of nodule risk prediction scores. Emerging applications including radiomics, machine learning and artificial intelligence (AI) in assessment and characterization of pulmonary nodules and role of these advanced techniques in the management of pulmonary nodules in the future are also illustrated.

Interstitial lung abnormalities (ILA) on routine chest CT: Comparison of radiologists’ visual evaluation and automated quantification

PurposeWe aimed to evaluate the performance of a fully automated quantitative software in detecting interstitial lung abnormalities (ILA) according to the Fleischner Society guidelines on routine chest CT compared with radiologists’ visual analysis. MethodThis retrospective single-centre study included participants with ILA findings and 1:2 matched controls who underwent routine chest CT using various CT protocols for health screening. Two thoracic radiologists independently reviewed the CT images using the Fleischner Society guidelines. We developed a fully automated quantitative tool for detecting ILA by modifying deep learning-based quantification of interstitial lung disease and evaluated its performance using the radiologists’ consensus for ILA as a reference standard. ResultsA total of 336 participants (mean age, 70.5 ± 6.1 years; M:F = 282:54) were included. Inter-reader agreements were substantial for the presence of ILA (weighted κ, 0.74) and fair for its subtypes (weighted κ, 0.38). The quantification system for identifying ILA using a threshold of 5 % in at least one zone showed 67.6 % sensitivity, 93.3 % specificity, and 90.5 % accuracy. Eight of 20 (40 %) false positives identified by the system were underestimated by readers for ILA extent. Contrast-enhancement in a certain vendor and suboptimal inspiration caused a true false-positive on the system (all P < 0.05). The best cut-off value of abnormality extent detecting ILA on the system was 3.6 % (sensitivity, 84.8 %; specificity 92.4 %). ConclusionsInter-reader agreement was substantial for ILA but only fair for its subtypes. Applying an automated quantification system in routine clinical practice may aid the objective identification of ILA.

Volume Doubling Time of Pulmonary Carcinoid Tumors Measured by Computed Tomography

IntroductionPulmonary carcinoid tumor (PCT) is a rare neuroendocrine lung neoplasm comprising approximately 2% of lung cancer diagnoses. It is classified as either localized low-grade (typical) or intermediate-grade (atypical) subtypes. PCT is known clinically to be a slow-growing cancer, however few studies have established its true growth rate when followed over time by computed tomography (CT). Therefore, we sought to determine the volume doubling time for PCTs as visualized on CT imaging. Materials and MethodsWe conducted a retrospective analysis of all PCTs treated at our institution between 2006 and 2020. Nodule dimensions were measured using a Picture Archiving and Communication System or retrieved from radiology reports. Volume doubling time was calculated using the Schwartz formula for PCTs followed by successive CT scans during radiographic surveillance. Consistent with Fleischner Society guidelines, tumors were considered to have demonstrated definitive growth by CT only when the interval change in tumor diameter was greater than or equal to 2 mm. ResultsThe median volume doubling time of 13 typical PCTs was 977 days, or 2.7 years. Five atypical PCTs were followed longitudinally, with a median doubling time of 327 days, or 0.9 years. ConclusionsTypical pulmonary carcinoid features a remarkably slow growth rate as compared to more common lung cancers. Our analysis of atypical pulmonary carcinoid included too few cases to offer definitive conclusions. It is conceivable that clinicians following current nodule surveillance guidelines may mistake incidentally detected typical carcinoids for benign non-growing lesions when followed for less than 2 years in low-risk patients.

Detection of lung carcinoma arising from ground glass opacities (GGO) after 5 years - A retrospective review

Pure ground glass opacities (GGO) may indicate pre-invasive subtypes of lung carcinoma. These neoplasms typically demonstrate indolent patterns of growth; Fleischner Society guidelines recommend up to five years of serial imaging. Our aim was to determine the frequency of diagnosed carcinoma arising from GGO detected beyond 5 years of surveillance. We reviewed pathologic diagnoses of lung carcinoma (n = 442) between 2016 and 2018 of a tertiary academic hospital and National Cancer Institute-designated cancer center to identify all cancers that arose from ground glass opacities detected on CT scan. Of the 442 cases of lung carcinoma, 32 (7%) were found that arose from pure GGOs and were ultimately diagnosed as cancer. Among the subgroup of GGOs, 78% (n = 25) were diagnosed within five years of surveillance, but up to 22% (n = 7) required between five and twelve years of serial follow up prior to definitive diagnosis. In order to detect 95% of cancers, GGOs would need to be followed for 7.9–12.7 years based upon a Kaplan-Meier estimate (p = 0.05). No patients who had lung carcinoma arising from GGOs died (0/32) within a follow-up time of one to three years. These data suggest that a greater number of lung carcinomas would be detected upon routine follow up of GGOs that extended beyond the current recommendation of five years. The overall survival of the cohort was 100%, consistent with existing data that these cancers are indolent. It is unknown whether a higher detection rate from longer interval follow up would impact overall survival.

The Chain of Adherence for Incidentally Detected Pulmonary Nodules after an Initial Radiologic Imaging Study: A Multisystem Observational Study.

Rationale: Millions of people are diagnosed with incidental pulmonary nodules every year. Although most nodules are benign, it is universally recommended that all patients be assessed to determine appropriate follow-up and ensure that it is obtained. Objectives: To determine the degree of concordance and adherence to 2005 Fleischner Society guidelines among radiologists, clinicians, and patients at two Veterans Affairs healthcare systems with incidental nodule tracking systems. Methods: Trained researchers abstracted data from the electronic health records of patients with incidental pulmonary nodules as identified by interpreting radiologists from 2008 to 2016. We classified radiology reports and patient follow-up into three categories. Radiologist-Fleischner adherence was the agreement between the radiologist's recommendation in the computed tomography (CT) report and the 2005 Fleischner Society guidelines. Clinician/patient-Fleischner concordance was agreement between patient follow-up and the guidelines. Clinician/patient-radiologist adherence was agreement between the radiologist's recommendation and patient follow-up. We evaluated whether the recommendation or follow-up was more (e.g., sooner) or less (e.g., later) aggressive than recommended. Results: After exclusions, 4,586 patients with 7,408 imaging tests (n = 4,586 initial chest CT scans; n = 2,717 follow-up chest CT scans; n = 105 follow-up low-dose CT scans) were included. Among radiology reports that could be classified in terms of Fleischner Society guidelines (n = 3,150), 80% had nonmissing radiologist recommendations. Among those reports, radiologist-Fleischner adherence was 86.6%, with 4.8% more aggressive and 8.6% less aggressive. Among patients whose initial scans could be classified, clinician/patient-Fleischner concordance was 46.0%, 14.5% were more aggressive, and 39.5% were less aggressive. Clinician/patient-radiologist adherence was 54.3%. Veterans whose radiology reports were adherent to Fleischner Society guidelines had a substantially higher proportion of clinician/patient-Fleischner concordance: 52.0% concordance among radiologist-Fleischner adherent versus 11.6% concordance among radiologist-Fleischner nonadherent. Conclusions: In this multi-health system observational study of incidental pulmonary nodule follow-up, we found that radiologist adherence to 2005 Fleischner Society guidelines may be necessary but not sufficient. Our results highlight the many facets of care processes that must occur to achieve guideline-concordant care.

Nodule net: A centralized prospective lung nodule tracking and safety-net program

BackgroundInadequate follow-up of suspicious lung nodules can result in diagnostic delays and potential progression to advanced lung cancer. In 2015, a multidisciplinary lung nodule management program, Nodule Net, was implemented to increase the timely follow-up rate. In this study, we sought to evaluate the effectiveness of the program. Methods2398 chest CT reports were reviewed for the presence of a lung nodule. Baseline demographics, nodule characteristics, and follow-up recommendations were collected. For reports that did not include structured recommendations, Fleischner Society guidelines were applied if appropriate. The rate of follow-up imaging was recorded and compared with historical rates. ResultsLung nodules were reported on 1367 (57%) of scans. Of the 632 participants with recommendations for follow-up, the Nodule Net nurse navigator was notified on 523 (83%). Of these, 408 (78%) completed follow-up, compared to 57/109 (52%) in those who were not reported to Nodule Net tracking system (risk ratio: 1.49, 95% CI: 1.24–1.79, p-value < 0.05). Out of these 408, nodule net outreach was required to prompt the follow-up in 116 (28%). Of these, a lung malignancy was diagnosed in 4 (4%). ConclusionsManagement of lung nodules is a complex process. Implementation of a lung nodule tracking program led to a significant increase in the completion of recommended follow-up imaging compared with usual care. Developing a comprehensive lung nodule program using an automated software system rather than manual processes to refer and track incidental findings may further reduce barriers to completion of follow-up.

Multidisciplinary virtual management of pulmonary nodules

Introduction and objectivesMultidisciplinary nodule clinics provide high-quality care and favor adherence to guidelines. Virtual care has shown savings benefits along with patient satisfaction. Our aim is to describe the first year of operation of a multidisciplinary virtual lung nodule clinic, the population evaluated and issued decisions. Secondarily, among discharged patients, we aimed to analyze their follow-up prior to the existence of our consultation, evaluating its adherence to guidelines. Materials and methodsObservational study including all patients evaluated at the Virtual Lung Nodule Clinic (VLNC) (March 2018- March 2019). Clinical and radiological data were recorded. Recommendations, based on 2017 Fleischner Society guidelines, were categorized into follow-up, discharge or referral to lung cancer consultation. Discharged patients were classified according to adherence to guidelines of their previous management, into adequate, prolonged and non-indicated follow-up. ResultsA total of 365 patients (58.9% men; median age 64.0 years) were included. Sixty-four percent had smoking history and 23% had chronic obstructive pulmonary disease (COPD). Most nodules were solid (87.4%) and multiple (57.5%). The median diameter was 6.00 mm. 43.8% of patients were discharged following first VLNC evaluation. Among them, 27.5% had received appropriate follow-up, but 66.9% had received poor management. Patients with prolonged follow-up (33.1%) were older (67.0 vs 60.5 years) and had larger nodules (6.00 mm vs 5.00). Non-indicated follow-up patients (33.8%) were more non-smokers (77.8% vs 31.8%) and presented smaller nodules (4.00 vs 5.00 mm). ConclusionsDuring its first year of operation, the VLNC has evaluated a population with a relevant risk profile for lung cancer development, management of which should be cautious and adhere to guidelines. After the first VLNC assessment, approximately one-half of this population was discharged. It was noticeable that previous follow-up of discharged patients was found poorly adherent to guidelines, with a marked tendency to overmanagement.

Interstitial Lung Abnormalities, Emphysema, and Spirometry in Smokers

Most pulmonary conditions reduce FVC, but studies of patients with combined pulmonary fibrosis and emphysema demonstrate that reductions in FVC are less than expected when these two conditions coexist clinically. Do interstitial lung abnormalities (ILAs), chest CT imaging findings that may suggest an early stage of pulmonary fibrosis in individuals with undiagnosed disease, affect the association between emphysema and FVC? Measures of ILA and emphysema were available for 9,579 and 5,277 participants from phases 1 (2007-2011) and 2 (2012-2016) of the Genetic Epidemiology of Chronic Obstructive Pulmonary Disease Study (COPDGene), respectively. ILA were defined by Fleischner Society guidelines. Adjusted linear regression models were used to assess the associations and interactions among ILA, emphysema, measures of spirometry, and lung function. ILA were present in 528 (6%) and 580 (11%) of participants in phases 1 and 2 of COPDGene, respectively. ILA modified the association between emphysema and FVC (P< .0001 for interaction) in both phases. In phase 1, in those without ILA, a 5%increase in emphysema was associated with a reduction in FVC (-110mL; 95%CI, -121 to -100mL; P< .0001); however, in those with ILA, it was not (-11mL; 95%CI, -53 to 31; P= .59). In contrast, no interaction was found between ILA and emphysema on total lung capacity or on diffusing capacity of carbon monoxide. The presence of ILA attenuates the reduction in FVC associated with emphysema.

Practical application and validation of the 2018 ATS/ERS/JRS/ALAT and Fleischner Society guidelines for the diagnosis of idiopathic pulmonary fibrosis

BackgroundAccurate diagnosis of idiopathic pulmonary fibrosis (IPF) is essential to inform prognosis and treatment. In 2018, the ATS/ERS/JRS/ALAT and Fleischner Society released new diagnostic guidelines for usual interstitial pneumonitis (UIP)/IPF, adding Probable UIP as a CT category based on prior studies demonstrating this category had relatively high positive predictive value (PPV) for histopathologic UIP/Probable UIP. This study applies the 2018 ATS/ERS/JRS/ALAT and Fleischner Society guidelines to determine test characteristics of CT categories in academic clinical practice.MethodsCT and histopathology were evaluated by three thoracic radiologists and two thoracic pathologists. Comparison of consensus categorization by the 2018 ATS and Fleischner Society guidelines by CT and histopathology was performed.ResultsOf patients with CT UIP, 87% (PPV, 95% CI: 60–98%) had histopathologic UIP with 97% (CI: 90–100%) specificity. Of patients with CT Probable UIP, 38% (PPV, CI: 14–68%) had histopathologic UIP and 46% (PPV, CI: 19–75%) had either histopathologic UIP or Probable UIP, with 88% (CI: 77–95%) specificity. Patients with CT Indeterminate and Alternative Diagnosis had histopathologic UIP in 27% (PPV, CI: 6–61%) and 21% (PPV, CI: 11–33%) of cases with specificities of 90% (CI: 80–96%) and 25% (CI: 16–37%). Interobserver variability (kappa) between radiologists ranged 0.32–0.81.ConclusionsCT UIP and Probable UIP have high specificity for histopathologic UIP, and CT UIP has high PPV for histopathologic UIP. PPV of CT Probable UIP was 46% for combined histopathologic UIP/Probable UIP. Our results indicate that additional studies are needed to further assess and refine the guideline criteria to improve classification performance.

Association of the Intensity of Diagnostic Evaluation With Outcomes in Incidentally Detected Lung Nodules

Whether guideline-concordant lung nodule evaluations lead to better outcomes remains unknown. To examine the association between the intensity of lung nodule diagnostic evaluations and outcomes, safety, and health expenditures. This comparative effectiveness research study analyzed health plan enrollees at Kaiser Permanente Washington in Seattle, Washington, and Marshfield Clinic in Marshfield, Wisconsin, with an incidental lung nodule detected between January 1, 2005, and December 31, 2015. Included patients were 35 years or older, had no high suspicion of infection, had no history of malignant neoplasm, and had no evidence of advanced lung cancer on nodule detection. Data analysis was conducted from January 7 to August 19, 2020. With the 2005 Fleischner Society guidelines (selected for their applicability to the time frame under investigation) as the comparator, 2 other intensities of lung nodule evaluation were defined. Guideline-concordant evaluation followed the guidelines. Less intensive evaluation was the absence of recommended testing, longer-than-recommended surveillance intervals, or less invasive testing than recommended. More intensive evaluation consisted of testing when the guidelines recommended no further testing, shorter-than-recommended surveillance intervals, or more invasive testing than recommended. The main outcome was the proportion of patients with lung cancer who had stage III or IV disease, radiation exposure, procedure-related adverse events, and health expenditures 2 years after nodule detection. Among the 5057 individuals included in this comparative effectiveness research study, 1925 (38%) received guideline-concordant, 1863 (37%) less intensive, and 1269 (25%) more intensive diagnostic evaluations. The entire cohort comprised 2786 female patients (55%), and the mean (SD) age was 67 (13) years. Adjusted analyses showed that compared with guideline-concordant evaluations, less intensive evaluations were associated with fewer procedure-related adverse events (risk difference [RD], -5.9%; 95% CI, -7.2% to -4.6%), lower mean radiation exposure (-9.5 milliSieverts [mSv]; 95% CI, -10.3 mSv to -8.7 mSv), and lower mean health expenditures (-$10 916; 95% CI, -$16 112 to -$5719); no difference in stage III or IV disease was found among patients diagnosed with lung cancer (RD, 4.6%; 95% CI, -22% to +31%). More intensive evaluations were associated with more procedure-related adverse events (RD, +8.1%; 95% CI, +5.6% to +11%), higher mean radiation exposure (+6.8 mSv; 95% CI, +5.8 mSv to +7.8 mSv), and higher mean health expenditures ($20 132; 95% CI, +$14 398 to +$25 868); no difference in stage III or IV disease was observed (RD, -0.5%; 95% CI, -28% to +27%). This study found inconclusive evidence of an association between less intensive diagnostic evaluations and more advanced stage at lung cancer diagnosis compared with guideline-concordant care; higher intensities of diagnostic evaluations were associated with greater procedural complications, radiation exposure, and expenditures. These findings underscore the need for more evidence on better ways to evaluate lung nodules and to avoid unnecessarily intensive diagnostic evaluations of lung nodules.

Patient characteristics associated with adherence to pulmonary nodule guidelines

BackgroundWhile pulmonary nodule guidelines provide follow-up recommendations based on nodule size and malignancy risk, these are inconsistently followed in clinical practice. In this study, we sought to identify patient characteristics associated with guideline-concordant nodule follow-up. MethodsWe conducted a retrospective cohort study of patients diagnosed with a pulmonary nodule between 2011 and 2014 at Boston Medical Center. Appropriate nodule follow-up evaluation was based upon the 2005 Fleischner Society Guidelines. In primary analysis, we compared patients with guideline-concordant follow-up to those with delayed or absent follow-up. In secondary analysis, we compared those with any follow-up to those without follow-up as well as the rate of guideline-concordant follow-up in patients seen by a pulmonologist. ResultsOf 3916 patients diagnosed with a pulmonary nodule, 1117 were included for analysis. Overall, 598 (53.5%) patients received guideline-concordant follow-up. Lower rates of guideline concordance were seen in patients of Hispanic ethnicity (OR 0.60, 95% CI 0.36–1.00), while higher rates were seen for nodules 7–8 mm (OR 1.55, 95% CI 1.02–2.35) and nodules >8 mm (OR 1.49, 95% CI 1.01–2.20). Having a history of COPD (OR 1.75, 95% CI 1.26–2.43), and being seen by a pulmonologist (OR 1.97, 95% CI 1.51–2.58) were also associated with guideline concordance. Among patients seen by a pulmonologist, 62.2% received guideline-concordant follow-up. ConclusionOverall rates of pulmonary nodule follow-up are low. Patient ethnicity, COPD history, nodule size and involvement of a pulmonologist may impact follow-up rates and are potential targets for implementation interventions to improve pulmonary nodule follow-up.

Deep Learning in CT Images: Automated Pulmonary Nodule Detection for Subsequent Management Using Convolutional Neural Network.

PurposeThe purpose of this study is to compare the detection performance of the 3-dimensional convolutional neural network (3D CNN)-based computer-aided detection (CAD) models with radiologists of different levels of experience in detecting pulmonary nodules on thin-section computed tomography (CT).Patients and MethodsWe retrospectively reviewed 1109 consecutive patients who underwent follow-up thin-section CT at our institution. The 3D CNN model for nodule detection was re-trained and complemented by expert augmentation. The annotations of a consensus panel consisting of two expert radiologists determined the ground truth. The detection performance of the re-trained CAD model and three other radiologists at different levels of experience were tested using a free-response receiver operating characteristic (FROC) analysis in the test group.ResultsThe detection performance of the re-trained CAD model was significantly better than that of the pre-trained network (sensitivity: 93.09% vs 38.44%). The re-trained CAD model had a significantly better detection performance than radiologists (average sensitivity: 93.09% vs 50.22%), without significantly increasing the number of false positives per scan (1.64 vs 0.68). In the training set, 922 nodules less than 3 mm in size in 211 patients at high risk were recommended for follow-up CT according to the Fleischner Society Guidelines. Fifteen of 101 solid nodules were confirmed to be lung cancer.ConclusionThe re-trained 3D CNN-based CAD model, complemented by expert augmentation, was an accurate and efficient tool in identifying incidental pulmonary nodules for subsequent management.