Faculty Bibliography

This article proposes codes for the primary tumor categories of adenocarcinoma in situ (AIS) and minimally invasive adenocarcinoma (MIA), and a uniform way to measure tumor size in part-solid tumors for the 8th edition of the tumor, node and metastasis (TNM) classification of lung cancer. In 2011 new entities of AIS, MIA and lepidic predominant adenocarcinoma (LPA) were defined and were later incorporated in the 2015 World Health Organization classification of lung cancer. To fit these entities into the T component of the staging system the Tis category is proposed for AIS, specifying Tis (AIS) if it is to be distinguished from squamous cell carcinoma in situ to be designated Tis (SCIS). We also propose MIA to be classified as T1mi. Furthermore, the use of the invasive size for T-descriptor size follows a recommendation made in three editions of the UICC TNM Supplement since 2003. For tumor size, the greatest dimension should be reported both clinically and pathologically. In nonmucinous lung adenocarcinomas, the computed tomography (CT) findings of ground glass versus solid opacities tend to correspond respectively to lepidic versus invasive patterns seen pathologically. However, this correlation is not absolute; so when CT features suggest nonmucinous AIS, MIA and LPA, the suspected diagnosis and clinical staging, should be regarded as a preliminary assessment that is subject to revision after pathologic evaluation of resected specimens. The ability to predict invasive versus non-invasive size based on solid versus ground glass components is not applicable to mucinous AIS, MIA or invasive mucinous adenocarcinomas because they generally show solid nodules or consolidation on CT.

BACKGROUND: Clinical TNM staging is based on a qualitative assessment of features defining T descriptors and has been found suboptimal for predicting prognosis of patients with MPM. Previous work suggests that volumetric CT (VOLCT) is prognostic and, if found practical and reproducible, could improve clinical MPM classification.background METHODS: Six North American institutions electronically submitted clinical, pathologic and imaging data on patients with stages I-IV MPM to an established multicenter database and biostatistical center (BC). Two reference radiologists, blinded to clinical data, independently reviewed scans, calculated clinical TNM stage by standard criteria, performed semi-automated tumor volume calculations using commercially available software, and submitted the findings to BC. Study endpoints included feasibility of a multi-institutional VOLCT network, concordance of independent VOLCT assessments and association of VOLCT with pathologic T classification. RESULTS: Of 164 submitted cases, 129 were evaluated by both reference radiologists. Discordant clinical staging of most cases confirmed the inadequacy of current criteria. The overall correlation between VOLCT estimates was good (Spearman Corr. = 0.822), but some were significantly discordant. Root-cause analysis of the most discordant estimates identified four common sources of variability. Despite these limitations, median tumor volume estimates were similar within subgroups of cases representing each pathological T descriptor, and increased monotonically for each reference pathologist with increasing pathological T status.results CONCLUSIONS: Good correlation between VOLCT estimates obtained for most cases reviewed by two independent radiologists, and qualitative association of VOLCT with pathological T status combine to encourage further study. Identified sources of user error will inform design of a follow-on prospective trial to more formally assess inter-observer variability of VOLCT and its potential contribution to clinical MPM staging. CONCLUSION:

Purpose To examine the factors that affect inter- and intraobserver agreement for pulmonary nodule type classification on low-radiation-dose computed tomographic (CT) images, and their potential effect on patient management. Materials and Methods Nodules (n = 160) were randomly selected from the Dutch-Belgian Lung Cancer Screening Trial cohort, with equal numbers of nodule types and similar sizes. Nodules were scored by eight radiologists by using morphologic categories proposed by the Fleischner Society guidelines for management of pulmonary nodules as solid, part solid with a solid component smaller than 5 mm, part solid with a solid component 5 mm or larger, or pure ground glass. Inter- and intraobserver agreement was analyzed by using Cohen kappa statistics. Multivariate analysis of variance was performed to assess the effect of nodule characteristics and image quality on observer disagreement. Effect on nodule management was estimated by differentiating CT follow-up for ground-glass nodules, solid nodules 8 mm or smaller, and part-solid nodules smaller than 5 mm from immediate diagnostic work-up for solid nodules larger than 8 mm and part-solid nodules 5 mm or greater. Results Pair-wise inter- and intraobserver agreement was moderate (mean kappa, 0.51 [95% confidence interval, 0.30, 0.68] and 0.57 [95% confidence interval, 0.47, 0.71]). Categorization as part-solid nodules and location in the upper lobe significantly reduced observer agreement (P = .012 and P < .001, respectively). By considering all possible reading pairs (28 possible combinations of observer pairs x 160 nodules = 4480 possible agreements or disagreements), a discordant nodule classification was found in 36.4% (1630 of 4480), related to presence or size of a solid component in 88.7% (1446 of 1630). Two-thirds of these discrepant readings (1061 of 1630) would have potentially resulted in different nodule management. Conclusion There is moderate inter- and intraobserver agreement for nodule classification by using current recommendations for low-radiation-dose CT examinations of the chest. Discrepancies in nodule categorization were mainly caused by disagreement on the size and presence of a solid component, which may lead to different management in the majority of cases with such discrepancies. ((c)) RSNA, 2015.

A wide variety of pathologic processes, both benign and malignant, affect the central airways. These processes may be classified into 4 distinct groups: anatomic variants, lesions that result in focal or diffuse airway narrowing, and those that result in multinodular airway disorder. Key to the accurate assessment of the central airways is meticulous imaging technique, especially the routine acquisition of contiguous high-resolution, 1-mm to 1.5-mm images. These images enable high-definition axial, coronal, and sagittal reconstructions, as well as advanced imaging techniques, including minimum intensity projection images and virtual bronchoscopy. Current indications most commonly include patients presenting with signs and symptoms of possible central airway obstruction, with or without hemoptysis. In addition to diagnosing airway abnormalities, computed tomography (CT) also serves a critical complementary role to current bronchoscopic techniques for both diagnosing and treating airway lesions. Advantages of CT include noninvasive visualization of the extraluminal extent of lesions, as well as visualization of airways distal to central airways obstructions. As discussed and illustrated later, thorough knowledge of current bronchoscopic approaches to central airway disease is essential for optimal correlative CT interpretation.

Lung cancer screening with a low-dose chest CT scan can result in more benefit than harm when performed in settings committed to developing and maintaining high-quality programs. This project aimed to identify the components of screening that should be a part of all lung cancer screening programs. To do so, committees with expertise in lung cancer screening were assembled by the Thoracic Oncology Network of the American College of Chest Physicians (CHEST) and the Thoracic Oncology Assembly of the American Thoracic Society (ATS). Lung cancer program components were derived from evidence-based reviews of lung cancer screening and supplemented by expert opinion. This statement was developed and modified based on iterative feedback of the committees. Nine essential components of a lung cancer screening program were identified. Within these components 21 Policy Statements were developed and translated into criteria that could be used to assess the qualification of a program as a screening facility. Two additional Policy Statements related to the need for multisociety governance of lung cancer screening were developed. High-quality lung cancer screening programs can be developed within the presented framework of nine essential program components outlined by our committees. The statement was developed, reviewed, and formally approved by the leadership of CHEST and the ATS. It was subsequently endorsed by the American Association of Throacic Surgery, American Cancer Society, and the American Society of Preventive Oncology.

Airway stents are increasingly used to treat symptomatic patients with obstructive tracheobronchial diseases who are not amenable to surgical resection or who have poor performance status, precluding them from resection. The most common conditions that are treated with tracheobronchial stents are primary lung cancer and metastatic disease. However, stents have also been used to treat patients with airway stenosis related to a variety of benign conditions, such as tracheobronchomalacia, relapsing polychondritis, postintubation tracheal stenosis, postoperative anastomotic stenosis, and granulomatous diseases. Additionally, airway stents can be used as a barrier method in the management of esophagorespiratory fistulas. Many types of stents are available from different manufacturers. Principally, they are classified as silicone; covered and uncovered metal; or hybrid, which are made of silicone and reinforced by metal rings. The advantages and disadvantages of each type of airway stent are carefully considered when choosing the most appropriate stent for each patient. Multidetector computed tomography plays an important role in determining the cause and assessing the location and extent of airway obstruction. Moreover, it is very accurate in its depiction of complications after airway stent placement. (c)RSNA, 2014.

Objective: The International Early Lung Cancer Action Program (I-ELCAP) is a collaborative group designed to demonstrate reduction in lung cancer mortality by using low-dose computed tomography (CT) screening to identify early stage disease in high-risk individuals. While the majority of patients with stage I non-small cell lung cancer (NSCLC) were treated with surgical resection, some patients were treated with definitive radiation. This study explores the characteristics and outcomes of this population. Methods: Clinical stage I NSCLC patients in North America treated by radiotherapy or surgery alone were identified in the I-ELCAP database. All had undergone low-dose CT screening according to a common protocol from 1993 to 2009. Patient characteristics and lung cancer-specific Kaplan-Meier survival rates were compared. Results: From 32,521 baseline and 34,394 annual repeat screenings, 455 cases of clinical stage I NSCLC were identified. Only 12 of these patients (2.6 %) underwent definitive radiation with median follow-up of 5.3 years. These 12 patients when compared with the 376 patients treated by surgery alone were older (72 vs. 67 years, p = 0.01), had more pre-existing comorbidities (1.5 vs. 1.0, p = 0.005), but had no significant differences in male gender, pack-years of smoking, emphysema, or tumor size. The median radiation dose was 6,150 cGy. There was no difference in lung cancer-specific survival between surgery and radiation (92 vs. 90 %, p = 0.78). Conclusion: This is the first study to show outcomes of definitive radiation for stage I NSCLC in a screened population. Although only used in a small number of cases, there is no difference in lung cancer-specific survival when comparing definitive radiation to surgical resection. 2014 Springer-Verlag Berlin Heidelberg

In this review, we focus on the radiologic, clinical, and pathologic aspects primarily of solitary subsolid pulmonary nodules. Particular emphasis will be placed on the pathologic classification and correlative computed tomography (CT) features of adenocarcinoma of the lung. The capabilities of fluorodeoxyglucose positron emission tomography-CT and histologic sampling techniques, including CT-guided biopsy, endoscopic-guided biopsy, and surgical resection, are discussed. Finally, recently proposed management guidelines by the Fleischner Society and the American College of Chest Physicians are reviewed.