Lung imaging patterns in connective tissue disease-associated interstitial lung disease impact prognosis and immunosuppression response.

OBJECTIVES: Interstitial lung disease (ILD) in connective tissue diseases (CTD) have highly variable morphology. We aimed to identify imaging features and their impact on ILD progression, mortality and immunosuppression response. METHODS: Patients with CTD-ILD had high-resolution chest computed tomography (HRCT) reviewed by expert radiologists blinded to clinical data for overall imaging pattern (usual interstitial pneumonia [UIP]; non-specific interstitial pneumonia [NSIP]; organizing pneumonia [OP]; fibrotic hypersensitivity pneumonitis [fHP]; and other). Transplant-free survival and change in percent-predicted forced vital capacity (FVC) were compared using Cox and linear mixed effects models adjusted for age, sex, smoking, and baseline FVC. FVC decline after immunosuppression was compared with pre-treatment. RESULTS: Of 645 CTD-ILD patients, the frequent CTDs were systemic sclerosis (n = 215), rheumatoid arthritis (n = 127), and inflammatory myopathies (n = 100). NSIP was the most common pattern (54%), followed by UIP (20%), fHP (9%), and OP (5%). Compared with UIP, FVC decline was slower for NSIP (1.1%/year, 95%CI 0.2, 1.9) and OP (3.5%/year, 95%CI 2.0, 4.9), and mortality was lower for NSIP (HR 0.65, 95%CI 0.45, 0.93) and OP (HR 0.18, 95%CI 0.05, 0.57), but higher in fHP (HR 1.58, 95%CI 1.01, 2.40). The extent of fibrosis also predicted FVC decline and mortality. After immunosuppression, FVC decline was slower compared with pre-treatment in NSIP (by 2.1%/year, 95%CI 1.4, 2.8), with no change for UIP or fHP. CONCLUSION: Multiple radiologic patterns are possible in CTD-ILD, including a fHP pattern. NSIP and OP were associated with better outcomes and response to immunosuppression, while fHP had worse survival compared with UIP.

Differential prognostic significance of sarcopenia in metastatic esophageal squamous and adenocarcinoma.

BACKGROUND: Sarcopenia indicates poor prognosis in various malignancies. We evaluated the association of sarcopenia with overall (OS) and progression-free survival (PFS) in metastatic esophageal cancer (MEC) patients, a population often presenting with poor nutritional status. METHODS: In newly diagnosed MEC patients managed at the Princess Margaret (PM) Cancer Centre (diagnosed 2006-2015), total muscle area, visceral adiposity (VA), and subcutaneous adiposity (SA) were quantified on abdominal computed tomography at L3. Sarcopenia was determined using published cutoffs, based on sex and height. RESULTS: Of 202 MEC patients, most were male (166/82%), < 65 years (116/57%), and had adenocarcinoma histology (141/70%); 110/54% had recurrent MEC after initial curative-intent treatment; 92/46% presented with de novo MEC. At stage IV diagnosis, 20/10% were underweight, 97/48% were normal-weight and 84/42% were overweight/obese; 103/51% were sarcopenic. Sarcopenia was associated with worse median OS (4.6 vs. 7.9 months; log-rank p = 0.03) and 1-year survival, even after adjusting for other body composition variables (e.g., BMI, VA, and SA): adjusted-HR 1.51 [95% CI 1.1-2.2, p = 0.02]. In post hoc analysis, sarcopenia was highly prognostic in adenocarcinomas (p = 0.003), but not squamous cell carcinomas (SCC). In patients receiving palliative systemic treatment (104/51%), sarcopenia was associated with shorter PFS (p = 0.004) in adenocarcinoma patients (75/72%). CONCLUSIONS: In metastatic esophageal adenocarcinomas, sarcopenia is associated with worse PFS and OS. In metastatic esophageal SCC, there was a non-significant trend for worse PFS but no association with OS. In order to offset the poor prognosis associated with sarcopenia particularly in metastatic esophageal adenocarcinoma patients, future research should focus on possible countermeasures.

Chronic lung allograft dysfunction phenotype and prognosis by machine learning CT analysis.

BACKGROUND: Chronic lung allograft dysfunction (CLAD) is the principal cause of graft failure in lung transplant recipients and prognosis depends on CLAD phenotype. We used a machine learning computed tomography (CT) lung texture analysis tool at CLAD diagnosis for phenotyping and prognostication compared with radiologist scoring. METHODS: This retrospective study included all adult first double lung transplant patients (January 2010-December 2015) with CLAD (censored December 2019) and inspiratory CT near CLAD diagnosis. The machine learning tool quantified ground-glass opacity, reticulation, hyperlucent lung and pulmonary vessel volume (PVV). Two radiologists scored for ground-glass opacity, reticulation, consolidation, pleural effusion, air trapping and bronchiectasis. Receiver operating characteristic curve analysis was used to evaluate the diagnostic performance of machine learning and radiologist for CLAD phenotype. Multivariable Cox proportional hazards regression analysis for allograft survival controlled for age, sex, native lung disease, cytomegalovirus serostatus and CLAD phenotype. RESULTS: 88 patients were included (57 bronchiolitis obliterans syndrome (BOS), 20 restrictive allograft syndrome (RAS)/mixed and 11 unclassified/undefined) with CT a median 9.5 days from CLAD onset. Radiologist and machine learning parameters phenotyped RAS/mixed with PVV as the strongest indicator (area under the curve (AUC) 0.85). Machine learning hyperlucent lung phenotyped BOS using only inspiratory CT (AUC 0.76). Radiologist and machine learning parameters predicted graft failure in the multivariable analysis, best with PVV (hazard ratio 1.23, 95% CI 1.05-1.44; p=0.01). CONCLUSIONS: Machine learning discriminated between CLAD phenotypes on CT. Both radiologist and machine learning scoring were associated with graft failure, independent of CLAD phenotype. PVV, unique to machine learning, was the strongest in phenotyping and prognostication.

Influence of sarcopenia, clinical data, and 2-[18F] FDG PET/CT in outcome prediction of patients with early-stage adenocarcinoma esophageal cancer.

PURPOSE: To determine the prognostic value of sarcopenia measurements done on staging 2-[18F] FDG PET/CT together with metabolic activity of the tumor in patients with adenocarcinoma esophagogastric cancer with surgical treatment. METHODS: Patients with early-stage, surgically treated esophageal adenocarcinoma and available pre-treatment 2-[18F] FDG PET/CT were included. The standard uptake value (SUV) and SUV normalized by lean body mass (SUL) were recorded. Skeletal muscle index (SMI) was measured at the L3 level on the CT component of the PET/CT. Sarcopenia was defined as SMI < 34.4cm2/m2 in women and < 45.4cm2/m2 in men. RESULTS: Of the included 145 patients. 30% were sarcopenic at baseline. On the univariable Cox proportional hazards analysis, ECOG, surgical T and N staging, lymphovascular invasion (LVI) positive lymph nodes, and sarcopenia were significant prognostic factors concerning RFS and OS. On multivariable Cox regression analysis, surgical N staging (p = 0.025) and sarcopenia (p = 0.022) remained significant poor prognostic factors for OS and RFS. Combining the clinical parameters with the imaging-derived nutritional evaluation of the patient but not metabolic parameters of the tumor showed improved predictive ability for OS and RFS. CONCLUSION: Combining the patients' imaging-derived sarcopenic status with standard clinical data, but not metabolic parameters, offered an overall improved prognostic value concerning OS and RFS.

Assessment of lateral costal artery with CT angiography: determination of prevalence and vessel length in the general population and its potential impact for coronary artery bypass grafting.

OBJECTIVES: Standard treatment for severe coronary artery disease (CAD) is coronary artery bypass grafting (CABG). An underreported branch of the internal mammary artery, the lateral costal artery (LCA), can cause a steal phenomenon after CABG, resulting in angina. The aim of this study was to determine the prevalence and length of LCA based on CT angiography (CTA). METHODS: This retrospective study included adult patients undergoing a thoracic CTA between January 2016 and August 2018. Exclusion criteria were prior CABG, insufficient clinical information, or inadequate image quality. Two blinded, independent readers reviewed all studies for the prevalence of the LCA. Positive cases were reviewed by two readers (R1/R2) for side distribution and vessel length, measured in intercostal spaces (ICS). Study indication, aortic size, and coronary calcification were noted. RESULTS: LCA was present in up to 42/389 (11%) of studies (60.3 ± 16.7 years, 30 males). The LCA was most commonly unilateral (n = 23, 55%). Median vessel length was 2 ICS (IQR 0; 3). Logistic regression was not significant in vessel distribution for sex (OR 0.6, 95% CI 0.28-1.15; p = 0.11). Inter-observer agreement in detecting LCA was substantial (kappa 0.71, 95% CI 0.59-0.83) and excellent for side/length distribution (kappa 0.94, 95% CI 0.82-1.0; ICC 0.96, 95% CI 0.93-0.98). CONCLUSION: The LCA is uncommon and most often unilateral and extends the third rib. Radiologists should be aware of this vessel and its potential role in angina after CABG, particularly when large. KEY POINTS: • LCA is an uncommon normal variant that is reported to cause angina pectoris after CABG. • CT angiography can reliably detect the LCA. It is most often unilateral and spans two intercostal spaces.

Significance of phenotype change after chronic lung allograft dysfunction onset.

Definitions for chronic lung allograft dysfunction (CLAD) phenotypes were recently revised (2019 ISHLT consensus). Post-CLAD onset phenotype transition may occur as a result of change in obstruction, restriction, or RAS-like opacities (RLO). We aimed to assess the prevalence and prognostic implications of these transitions. This was a single-center, retrospective cohort study of bilateral lung transplants performed in 2009-2015. CLAD phenotypes were determined per ISHLT guidelines. CLAD phenotype transition was defined as a sustained change in obstruction, restriction or RLO. We specifically focused on phenotype changes based on RLO emergence. Association of RLO development with time to death or retransplant were assessed using Kaplan-Meier and Cox proportional hazards models. Among 211 patients with CLAD, 47 (22.2%) experienced a phenotype transition. Nineteen patients developed RLO. Development of RLO phenotype after CLAD onset was associated with a shorter time to death/retransplant when considering the entire CLAD patient cohort (HR = 4.00, CI 2.74-5.83, P < 0.001) and also when restricting the analysis to only patients with a Non-RLO phenotype at CLAD onset (HR 9.64, CI 5.52-16.84, P < 0.0001). CLAD phenotype change based on emergence of RAS-like opacities implies a worse outcome. This highlights the clinical importance of imaging follow-up to monitor for phenotype transitions after CLAD onset.

Computed Tomography of Contemporary Occupational Lung Disease: A Pictorial Review.

Occupational lung disease remains one of the most common work-related illnesses and accounts for most deaths from occupational illness. Occupational lung diseases often have delayed manifestation over decades and nonspecific clinical presentations, making it challenging for clinicians to promptly identify the disease and implement preventive measures. Radiologists play a crucial role in identifying and diagnosing occupational lung diseases, allowing for removal of the exposure and early medical intervention. In this review, we share our clinical and radiologic approach to diagnosing occupational lung disease and its subtypes. A collection of sample cases of occupational lung diseases commonly encountered in the modern era at a large Canadian university hospital is included to facilitate understanding. This review will provide radiologists with valuable insights into recognizing and diagnosing occupational lung diseases.

A radiographic score for human donor lungs on ex vivo lung perfusion predicts transplant outcomes.

BACKGROUND: Ex vivo lung perfusion (EVLP) is an advanced platform for isolated lung assessment and treatment. Radiographs acquired during EVLP provide a unique opportunity to assess lung injury. The purpose of our study was to define and evaluate EVLP radiographic findings and their association with lung transplant outcomes. METHODS: We retrospectively evaluated 113 EVLP cases from 2020-21. Radiographs were scored by a thoracic radiologist blinded to outcome. Six lung regions were scored for 5 radiographic features (consolidation, infiltrates, atelectasis, nodules, and interstitial lines) on a scale of 0 to 3 to derive a score. Spearman's correlation was used to correlate radiographic scores to biomarkers of lung injury. Machine learning models were developed using radiographic features and EVLP functional data. Predictive performance was assessed using the area under the curve. RESULTS: Consolidation and infiltrates were the most frequent findings at 1 hour EVLP (radiographic lung score 2.6 (3.3) and 4.6 (4.3)). Consolidation (r = -0.536 and -0.608, p < 0.0001) and infiltrates (r = -0.492 and -0.616, p < 0.0001) were inversely correlated with oxygenation (∆pO2) at 1 hour and 3 hours of EVLP. First-hour consolidation and infiltrate lung scores predicted transplant suitability with an area under the curve of 87% and 88%, respectively. Prediction of transplant outcomes using a machine learning model yielded an area under the curve of 80% in the validation set. CONCLUSIONS: EVLP radiographs provide valuable insight into donor lungs being assessed for transplantation. Consolidation and infiltrates were the most common abnormalities observed in EVLP lungs, and radiographic lung scores predicted the suitability of donor lungs for transplant.

Exercise and pulsatile pulmonary vascular loading in chronic thromboembolic pulmonary disease.

Chronic thromboembolic pulmonary disease (CTEPD) is characterized by organized nonresolving thrombi in pulmonary arteries (PA). In CTEPD with pulmonary hypertension (PH), chronic thromboembolic PH (CTEPH), early wave reflection results in abnormalities of pulsatile afterload and augmented PA pressures. We hypothesized that exercise during right heart catheterization (RHC) would elicit more frequent elevations of pulsatile vascular afterload than resistive elevations in patients with CTEPD without PH. The interdependent physiology of pulmonary venous and PA hemodynamics was also evaluated. Consecutive patients with CTEPD without PH (resting mean PA pressure ≤20 mmHg) undergoing an exercise RHC were identified. Latent resistive and pulsatile abnormalities of pulmonary vascular afterload were defined as an exercise mean PA pressure/cardiac output >3 WU, and PA pulse pressure to PA wedge pressure (PA PP/PAWP) ratio >2.5, respectively. Forty-five patients (29% female, 53 ± 14 years) with CTEPD without PH were analyzed. With exercise, 19 patients had no abnormalities (ExNOR), 26 patients had abnormalities (ExABN) of pulsatile (20), resistive (2), or both (4) elements of pulmonary vascular afterload. Exercise elicited elevations of pulsatile afterload (53%) more commonly than resistive afterload (13%) (p < 0.001). ExABN patients had lower PA compliance and higher pulmonary vascular resistance at rest and exercise and prolonged resistance-compliance time product at rest. The physiological relationship between changes in PA pressures relative to PAWP was disrupted in the ExABN group. In CTEPD without PH, exercise RHC revealed latent pulmonary vascular afterload elevations in 58% of patients with more frequent augmentation of pulsatile than resistive pulmonary vascular afterload.

Diagnostic Accuracy in Detecting Fungal Infection with Ultra-Low-Dose Computed Tomography (ULD-CT) Using Filtered Back Projection (FBP) Technique in Immunocompromised Patients.

Purpose: To compare the accuracy of ultra-low-dose (uLDCT) to standard-of-care low-dose chest CT (LDCT) in the detection of fungal infection in immunocompromised (IC) patients. Method and Materials: One hundred IC patients had paired chest CT scans performed with LDCT followed by uLDCT. The images were independently reviewed by three chest radiologists who assessed the image quality (IQ), diagnostic confidence, and detection of major (macro nodules, halo sign, cavitation, consolidation) and minor (4-10 mm nodules, ground-glass opacity) criteria for fungal disease using a five-point Likert score. Discrepant findings were adjudicated by a fourth chest radiologist. Box-whisker plots were used to analyze IQ and diagnostic confidence. Inter-rater reliability was assessed using interclass correlation coefficients (ICCs). The statistical difference between LDCT and uLDCT results was assessed using Wilcoxon paired test. Results: Lung reconstructions had IQ and diagnostic confidence scores (mean ± std) of 4.52 ± 0.47 and 4.63 ± 0.51 for LDCT and 3.85 ± 0.77 and 4.01 ± 0.88 for uLDCT. The images were clinically acceptable except for uLDCT in obese patients (BMI ≥ 30 kg/m2), which had an IQ ranking from poor to excellent (scores 1 to 5). The accuracy in detecting major and minor radiological findings with uLDCT was 96% and 84% for all the patients. The inter-rater agreements were either moderate, good, or excellent, with ICC values of 0.51-0.96. There was no significant statistical difference between the uLDCT and LDCT ICC values (p = 0.25). The effective dose for uLDCT was one quarter that of LDCT (CTDIvol = 0.9 mGy vs. 3.7 mGy). Conclusions: Thoracic uLDCT, at a 75% dose reduction, can replace LDCT for the detection of fungal disease in IC patients with BMI < 30.0 kg/m2.

Predictive [18F]-FDG PET/CT-Based Radiogenomics Modelling of Driver Gene Mutations in Non-small Cell Lung Cancer.

RATIONALE AND OBJECTIVES: To investigate whether [18F]-FDG PET/CT-derived radiomics may correlate with driver gene mutations in non-small cell lung cancer (NSCLC) patients. MATERIALS AND METHODS: In this IRB-approved retrospective study, 203 patients with surgically treated NSCLC who underwent subsequent genomic analysis of the primary tumour at our institution between December 2004 and January 2014 were identified. Of those, 128 patients (mean age 62.4 ± 10.8 years; range: 35-84) received preoperative [18F]-FDG PET/CT as part of their initial staging and thus were included in the study. PET and CT image segmentation and feature extraction were performed semi-automatically with an open-source software platform (LIFEx, Version 6.30, lifexsoft.org). Molecular profiles using different next-generation sequencing (NGS) panels were collected from a web-based resource (cBioPortal.ca for Cancer genomics). Two statistical models were then built to evaluate the predictive ability of [18F]-FDG PET/CT-derived radiomics features for driver gene mutations in NSCLC. RESULTS: More than half (68/128, 53%) of all tumour samples harboured three or more gene mutations. Overall, 55% of tumour samples demonstrated a mutation in TP53, 26% of samples had alterations in KRAS and 17% in EGFR. Extensive statistical analysis resulted in moderate to good predictive ability. The highest Youden Index for TP53 was achieved using combined PET/CT features (0.70), for KRAS using PET features only (0.57) and for EGFR using CT features only (0.60). CONCLUSION: Our study demonstrated a moderate to good correlation between radiomics features and driver gene mutations in NSCLC, indicating increased predictive ability of genomic profiles using combined [18F]-FDG PET/CT-derived radiomics features.

Respiratory oscillometry with CT image analysis in idiopathic pulmonary fibrosis following single lung transplant.

Oscillometry is an emerging pulmonary function testing tool that is conducted during tidal breaths with minimal patient effort. It is highly sensitive to changes in lung mechanics. Oscillometry was recently shown to be highly associated with disease severity in idiopathic pulmonary fibrosis (IPF). The usefulness of oscillometry after single lung transplant in IPF patients is not well understood. Our study demonstrated that oscillometry can detect changes in the graft despite presence of a native fibrotic lung to provide useful information to complement spirometry.

Bronchoalveolar Lavage Fluid Cellular Analysis and Radiologic Patterns in Patients with Fibrotic Interstitial Lung Disease.

BACKGROUND: Bronchoalveolar lavage (BAL) cellular analysis is often recommended during the initial diagnostic evaluation of fibrotic ILD. Despite recommendation for its use, between-center heterogeneity exists and supportive data concerning the clinical utility and correlation of BAL findings with radiologic features or patterns remains sparse. RESEARCH QUESTION: In patients with fibrotic ILD, are BAL findings associated with radiologic features, patterns, and clinical diagnoses? METHODS: Patients with fibrotic ILD who underwent BAL for diagnostic evaluation and enrolled in the prospective Canadian Registry for Pulmonary Fibrosis were re-reviewed in a standardized multidisciplinary discussion (MDD). BAL was categorized according to guideline-recommended thresholds, and also using thresholds of lymphocytosis>20% and neutrophils>4.5%. High-resolution computed tomography (HRCT) scans were scored (blinded to clinical data) for specific features and percentage lung involvement. Radiologists classified HRCTs according to guideline-defined patterns for idiopathic pulmonary fibrosis (IPF) and fibrotic hypersensitivity pneumonitis (fHP), then MDD diagnoses were assigned, considering all available data. RESULTS: Bronchoscopy with cellular analysis was performed in 209/1593 (13%) patients. Lymphocyte% was weakly negatively correlated with total fibrosis% (r=-0.16, p=0.023) but not statistically significantly correlated with ground glass opacity% (r=0.01, p=0.94). A mixed BAL pattern was the most frequent in all radiologic patterns (range 45% to 69%), with a minority classifiable according to BAL guidelines. BAL lymphocytosis appeared with similar frequency across HRCT patterns of fHP (21%) and UIP (18%). Only 5% of patients with MDD-based fHP had a guideline defined isolated lymphocytosis >15%. INTERPRETATION: BAL cellular analyses did not significantly correlate with radiologic features, guideline patterns, or MDD-based diagnoses. Ground glass opacities are often interpreted to represent pulmonary inflammation, but were not associated with BAL lymphocytosis in this cohort.

Risk-based lung cancer screening performance in a universal healthcare setting.

Globally, lung cancer is the leading cause of cancer death. Previous trials demonstrated that low-dose computed tomography lung cancer screening of high-risk individuals can reduce lung cancer mortality by 20% or more. Lung cancer screening has been approved by major guidelines in the United States, and over 4,000 sites offer screening. Adoption of lung screening outside the United States has, until recently, been slow. Between June 2017 and May 2019, the Ontario Lung Cancer Screening Pilot successfully recruited 7,768 individuals at high risk identified by using the PLCOm2012noRace lung cancer risk prediction model. In total, 4,451 participants were successfully screened, retained and provided with high-quality follow-up, including appropriate treatment. In the Ontario Lung Cancer Screening Pilot, the lung cancer detection rate and the proportion of early-stage cancers were 2.4% and 79.2%, respectively; serious harms were infrequent; and sensitivity to detect lung cancers was 95.3% or more. With abnormal scans defined as ones leading to diagnostic investigation, specificity was 95.5% (positive predictive value, 35.1%), and adherence to annual recall and early surveillance scans and clinical investigations were high (>85%). The Ontario Lung Cancer Screening Pilot provides insights into how a risk-based organized lung screening program can be implemented in a large, diverse, populous geographic area within a universal healthcare system.

Chronic thromboembolic pulmonary hypertension secondary to a vascular malformation: case report diagnosis by lung subtraction iodine mapping.

Chronic thromboembolic pulmonary hypertension (CTEPH) is a challenging diagnosis that can occur even in the absence of a prior thrombotic event. The main screening test is ventilation-perfusion (VQ) scintigraphy. The gold standard treatment for CTEPH is pulmonary endarterectomy (PEA), however, balloon pulmonary angioplasty (BPA) is an emerging treatment, especially for CTEPH at the segmental level. We report on a case of a patient with segmental CTEPH diagnosed by lung subtraction iodine mapping (LSIM) in the context of a chest wall vascular malformation. CTEPH was treated with BPA and by embolization and ligation of their vascular malformation.

An unusual case of interstitial lung disease: Revisiting peribronchiolar metaplasia interstitial lung disease (PBM-ILD).

Peribronchiolar metaplasia (PBM) is a histological finding of uncertain significance commonly seen in interstitial lung disease (ILD). PBM is thought to be secondary to small airway injury from insults such as tobacco smoke and other environmental exposures. The term PBM-ILD has been proposed for patients with ILD where PBM is the major histologic finding, however a lack of radiographic changes supportive of ILD in previously reported cases has limited recognition of the diagnosis. We present a rare case of welding-associated ILD with clinical, radiographic, and histologic evidence consistent with the proposed definition of PBM-ILD. We outline an approach to its consideration as a diagnosis based on our experience through multidisciplinary discussion.

Managing the Risk of Lung Toxicity with Trastuzumab Deruxtecan (T-DXd): A Canadian Perspective.

Ongoing advances in precision cancer therapy have increased the number of molecularly targeted and immuno-oncology agents for a variety of cancers, many of which have been associated with a risk of pulmonary complications, among the most concerning being drug-induced interstitial lung disease/pneumonitis (DI-ILD). As the number of patients undergoing treatment with novel anticancer agents continues to grow, DI-ILD is expected to become an increasingly significant clinical challenge. Trastuzumab deruxtecan (T-DXd) is an antibody-drug conjugate targeting human epidermal growth factor receptor 2 that is gaining widespread use in the metastatic breast cancer setting and is undergoing exploration for other oncologic indications. ILD/pneumonitis is an adverse event of special interest associated with T-DXd, which has potentially fatal consequences if left untreated and allowed to progress. When identified in the asymptomatic stage (grade 1), T-DXd-related ILD can be monitored and treated effectively with the possibility of treatment continuation. Delayed diagnosis and/or treatment, however, results in progression to grade 2 or higher toxicity and necessitates immediate and permanent discontinuation of this active agent. Strategies are, therefore, needed to optimize careful monitoring during treatment to ensure patient safety and optimize outcomes. Several guidance documents have been developed regarding strategies for the early identification and management of T-DXd-related ILD, although none have been within the context of the Canadian health care environment. A Canadian multidisciplinary steering committee was, therefore, convened to evaluate existing recommendations and adapt them for application in Canada. A multidisciplinary approach involving collaboration among medical oncologists, radiologists, respirologists, and allied health care professionals is needed to ensure the proactive identification and management of T-DXd-related ILD and DI-ILD associated with other agents with a similar toxicity profile.

Enhancing preoperative assessment in chronic thromboembolic pulmonary hypertension: A comprehensive analysis of interobserver agreement and proximity-based CT pulmonary angiography scoring.

Background: Surgical risk in chronic thromboembolic pulmonary hypertension (CTEPH) depends on the proximity of thromboembolism on CT pulmonary angiography (CTPA). We assessed interobserver agreement for the quantification of thromboembolic lesions in CTEPH using a novel CTPA scoring index. Methods: Forty CTEPH patients (mean age, 58 ± 16 years; 19 men) with preoperative CTPA who underwent pulmonary endarterectomy (PEA) (08/2020-09/2021) were retrospectively included. Three radiologists scored each CTPA for chronic thromboembolism (occlusions, eccentric thickening, webs) using a 32-vessel model of the pulmonary vasculature, with interobserver agreement evaluated using Fleiss' kappa. CT level of disease was determined by the most proximal chronic thromboembolism: level 1 (main pulmonary artery), 2 (lobar), 3 (segmental) and 4 (subsegmental), and compared to surgical level at PEA. Results: Interobserver agreement for CT level of disease was moderate overall (κ = 0.52). Agreement was substantial overall at the main/lobar level (κ, mean = 0.71) when excluding the left upper lobe (κ = 0.17). Though segmental and subsegmental agreement suffered (κ = 0.31), we found substantial agreement for occlusions (κ = 0.72) compared to eccentric thickening (κ = 0.45) and webs (κ = 0.14). Correlation between CT level and surgical level was strong overall (τb = 0.73) and in the right lung (τb = 0.68), but weak in the left lung (τb = 0.42) (p < 0.05). Radiologists often over- and underestimated the proximal extent of disease in right and left lung, respectively. Conclusions: CT level of disease demonstrated good agreement between radiologists and was highly predictive of the surgical level in CTEPH. Occlusions were the most reliable sign of chronic thromboembolism and are important in assessing the segmental vasculature.