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Lung cancer is a leading cause of cancer-related mortality worldwide. Imaging is integral in accurate clinical staging to stratify patients into groups to predict survival and determine treatment. The eighth edition of the tumor, node, and metastasis (TNM-8) staging system proposed by the International Association for the Study of Lung Cancer in 2016, accepted by both the Union for International Cancer Control and the American Joint Committee on Cancer, is the current standard method of staging lung cancer. This single TNM staging is used for all histologic subtypes of lung cancer, including nonsmall cell lung cancer, small cell lung cancer, and bronchopulmonary carcinoid tumor, and it addresses both clinical and pathologic staging. Familiarity with the strengths and limitations of imaging modalities used in staging, the nuances of TNM-8, its correct nomenclature, and potential pitfalls are important to optimize patient care. In this article, we discuss the role of computed tomography (CT) and positron emission tomography/CT in lung cancer staging, as well as current imaging recommendations pertaining to TNM-8.

In the oncologic setting, misinterpretation of fluid in pericardial recesses as mediastinal adenopathy or benign pericardial findings as malignant can lead to inaccurate staging and inappropriate management. Knowledge of normal pericardial anatomy, imaging features to differentiate fluid in pericardial sinuses and recesses from mediastinal adenopathy and potential pitfalls in imaging of the pericardium on CT and PET/CT is important to avoid misinterpretation.

In imaging of the mediastinum, advances in computed tomography (CT), and magnetic resonance imaging (MRI) technology enable improved characterization of mediastinal masses. Knowledge of the boundaries of the mediastinal compartments is key to accurate localization. Awareness of distinguishing imaging characteristics allows radiologists to suggest a specific diagnosis or narrow the differential. In certain situations, MRI adds value to further characterize mediastinal lesions.

Fungal pneumonia is the most frequent presentation of invasive fungal infections (IFIs) in patients with hematologic malignancies (HM) and hematopoietic stem cell transplantation (HSCT) recipients. The most common causes include Aspergillus, Mucor, Fusarium, and Candida species. The high incidence and high morbidity and mortality rate of fungal pneumonias in HM/HSCT populations arise from severe immune dysfunction that may be caused by both the underlying disease and/or its treatment. CT is routinely used when pulmonary complications are suspected after HSCT. Appropriate image interpretation of the posttransplant patient requires a combination of pattern recognition and knowledge of the clinical setting. In this article, we provide an overview of the clinical manifestations and CT imaging features of the most common invasive fungal pneumonias (IFPs) seen in severely immunosuppressed hosts.

Myriad conditions may affect both the neurologic system and the thorax, while other diseases primarily affecting the thorax may manifest with neurologic abnormalities. Correlation of signs, symptoms, and imaging findings in the neurological system with those in the thorax can help diagnose certain conditions and/or guide further diagnostic work-up and treatment. We will review and illustrate the imaging appearance of several systemic/neurological diseases with thoracic manifestations as well as discuss conditions in the thorax that can lead to neurologic symptoms.

Thymic carcinomas are rare malignancies that in general arise in the prevascular (anterior) mediastinum. These tumors are usually invasive, often present at advanced stages, and typically behave aggressively. Studies are hampered by the paucity of these tumors, the large variety of carcinoma subtypes, and the lack of unique morphologic and immunophenotypic features. Despite these challenges, advances in diagnostic imaging, surgical approaches, systemic therapies, and radiation therapy techniques have been made. The WHO classification of thymic epithelial tumors has been updated in 2021, and the eighth tumor nodal metastasis staging by the American Joint Committee on Cancer/Union for International Cancer Control included thymic carcinomas in 2017. Molecular alterations that provide more insight into the pathogenesis of these tumors and that potentially permit use of novel targeted therapies are increasingly being identified. New approaches to radiation therapy, chemotherapy, and immunotherapy are under evaluation. International societies, including the International Thymic Malignancy Interest Group, European Society of Thoracic Surgeons, and Japanese, Chinese, and Korean thymic associations, have been critical in organizing and conducting multi-institutional clinical studies. Herein, we review contemporary multidisciplinary perspectives in diagnosis and management of thymic carcinoma.

Tracheobronchial obstruction, haemoptysis, and airway fistulas caused by airway involvement by primary or metastatic malignancies may result in dyspnoea, wheezing, stridor, hypoxaemia, and obstructive atelectasis or pneumonia, and can lead to life-threatening respiratory failure if untreated. Complex minimally invasive endobronchial interventions are being used increasingly to treat cancer patients with tracheobronchial conditions with curative or, most often, palliative intent, to improve symptoms and quality of life. The selection of the appropriate treatment strategy depends on multiple factors, including tumour characteristics, whether the lesion is predominately endobronchial, shows extrinsic compression, or a combination of both, the patient's clinical status, the urgency of the clinical scenario, physician expertise, and availability of tools. Pre-procedure multidetector computed tomography (MDCT) imaging can aid in the most appropriate selection of bronchoscopic treatment. Follow-up imaging is invaluable for the early recognition and management of any potential complication. This article reviews the most commonly used endobronchial procedures in the oncological setting and illustrates the role of MDCT in planning, assisting, and follow-up of endobronchial therapeutic procedures.

Non-small-cell lung cancer (NSCLC) is frequently diagnosed when it is not amenable to local therapies; therefore, systemic agents are the mainstay of therapy for many patients. In recent years, treatment of advanced NSCLC has evolved from a general approach primarily involving chemotherapy to a more personalised strategy in which biomarkers such as the presence of genomic tumour aberrations and the expression of immune proteins such as programmed death-ligand 1 (PD-L1), in combination with other elements of clinical information such as histology and clinical stage, guide management. For instance, pathways resulting in uncontrolled growth and proliferation of tumour cells due to epidermal growth factor receptor (EGFR) mutations and anaplastic lymphoma kinase (ALK) rearrangements may be targeted by tyrosine kinase inhibitors (TKIs). In this article, we review the current state of medical oncology, imaging characteristics of mutations, pitfalls in response assessments and the imaging of complications.

Chimeric antigen receptor (CAR) T-cell therapy is a recently approved breakthrough treatment that has become a new paradigm in treatment of recurrent or refractory B-cell lymphomas and pediatric or adult acute lymphoid leukemia. CAR T cells are a type of cellular immunotherapy that artificially enhances T cells to boost eradication of malignancy through activation of the native immune system. The CAR construct is a synthetically created functional cell receptor grafted onto previously harvested patient T cells, which bind to preselected tumor-associated antigens and thereby activate host immune signaling cascades to attack tumor cells. Advantages include a single treatment episode of 2-3 weeks and durable disease elimination, with remission rates of over 80%. Responses to therapy are more rapid than with conventional chemotherapy or immunotherapy, with intervening short-interval edema. CAR T-cell administration is associated with therapy-related toxic effects in a large percentage of patients, notably cytokine release syndrome, immune effect cell-associated neurotoxicity syndrome, and infections related to immunosuppression. Knowledge of the expected evolution of therapy response and potential adverse events in CAR T-cell therapy and correlation with the timeline of treatment are important to optimize patient care. Some toxic effects are radiologically evident, and familiarity with their imaging spectrum is key to avoiding misinterpretation. Other clinical toxic effects may be occult at imaging and are diagnosed on the basis of clinical assessment. Future directions for CAR T-cell therapy include new indications and expanded tumor targets, along with novel ways to capture T-cell activation with imaging.

By boosting the immune system, immunotherapy with immune checkpoint inhibitors (ICIs) has altered the management of patients with various cancers including those with metastatic non-small cell lung cancer (NSCLC). As a result of immune system activation, ICIs are associated with unique response patterns (that are not addressed by traditional response criteria) and inflammatory side effects termed immune-related adverse events. In this article, we will review the role of immunotherapy in cancer treatment, specifically ICIs used in NSCLC treatment, radiological response criteria of immunotherapy, and the imaging spectrum of immune-related adverse events.

Malignant pleural mesothelioma is a rare tumor arising from the pleural mesothelial cells. Imaging plays a crucial role in the diagnosis, staging, and management of patients with mesothelioma. Accurate staging to stratify patients into homogeneous groups is required to evaluate the effectiveness of multimodality therapeutic regimens. CT and PET/CT are recommended for the initial staging of MPM. MRI adds value to further assess invasion of the tumor into the diaphragm, chest wall, and mediastinum. This review will discuss pearls and pitfalls in the imaging of mesothelioma with emphasis on the roles of CT, MRI, and PET/CT.

Malignant mesothelioma is a rare tumor arising from the mesothelial cells that line the pleura, pericardium, peritoneum, and tunica vaginalis. Imaging plays a primary role in the diagnosis, staging, and management of malignant mesothelioma. Multimodality imaging, including radiography, computed tomography (CT), magnetic resonance imaging (MRI), and F-18 fluorodeoxyglucose positron emission tomography/computed tomography (FDG PET/CT), is used in a variety of scenarios, including diagnosis, guidance for tissue sampling, staging, and reassessment of disease after therapy. CT is the primary imaging modality used in staging. MRI has superior contrast resolution compared with CT and can add value in terms of determining surgical resectability in equivocal cases. MRI can further assess the degree of local invasion, particularly into the mediastinum, chest wall, and diaphragm, for malignant pleural and pericardial mesotheliomas. FDG PET/CT plays a role in the diagnosis and staging of malignant pleural mesothelioma (MPM) and has been shown to be more accurate than CT, MRI, and PET alone in the staging of malignant pleural mesothelioma. PET/CT can also be used to target lesions for biopsy and to assess prognosis, treatment response, and tumor recurrence.

To report early findings from a phase II trial of high-dose radiotherapy (HD-RT) with or without low-dose RT (LD-RT) for metastatic cancer.Eligible patients had metastatic disease that progressed on immunotherapy within 6 months. Patients were given either HD-RT (20-70 Gy total; 3-12.5 Gy/f), or HD-RT + LD-RT (0.5-2 Gy/f up to 1-10 Gy total) to separate lesions, with continued immunotherapy. Radiographic response was assessed per RECIST 1.1 and Immune-Related Response Criteria (irRC). Primary endpoints: (1) 4-month disease control (DCR, complete/partial response [CR/PR] or stable disease [SD]) or an overall response (ORR, CR/PR) at any point in ≥10% of patients, per RECIST 1.1; (2) dose-limiting toxicity within 3 months not exceeding 30%. Secondary endpoint was lesion-specific response.Seventy-four patients (NSCLC, n = 38; melanoma n = 21) were analyzed (39 HD-RT and 35 HD-RT + LD-RT). The median follow-up time was 13.6 months. The primary endpoint was met for 72 evaluable patients, with a 4-month DCR of 42% (47% [16/34] vs. 37% [14/38] in HD-RT + LD-RT vs. HD-RT, P = 0.38), and 19% ORR at any time (26% [9/34] vs. 13% [5/38] in HD-RT + LD-RT vs. HD-RT, P = 0.27). Three patients had toxicity ≥grade 3. LD-RT lesion response (53%) was improved compared to nonirradiated lesions in HD-RT + LD-RT (23%, P = 0.002) and HD-RT (11%, P 0.001). T- and NK cell infiltration was enhanced in lesions treated with LD-RT.HD-RT plus LD-RT safely improved lesion-specific response in patients with immune resistant solid tumors by promoting infiltration of effector immune cells into the tumor microenvironment.

Immune checkpoint inhibitors (ICIs), a form of immunotherapy, are increasingly used for a variety of malignancies and have been linked to numerous treatment-related side effects known as immune-related adverse events (irAEs). IrAEs can affect multiple organ systems and are important to recognise in order to avoid misinterpretation as progressive tumour and to ensure appropriate management. In this pictorial review, we will briefly discuss radiological response criteria of immunotherapy and describe the imaging appearances of the wide spectrum of these ICI-associated toxicities.

This review focuses on 2 fat-containing entities in the mediastinum that may raise a diagnostic challenge: Morgagni's hernia and Epipericardial (mediastinal) fat necrosis. Familiarity with the typical imaging findings of these 2 entities is vital for the radiologist to recognize and accurately characterize unusual mediastinal pathological conditions.

Pulmonary embolism (PE) can present with a wide spectrum of clinical symptoms that can overlap considerably with other cardiovascular diseases. To avoid PE related morbidity and mortality, it is vital to identify this disease accurately and in a timely fashion. Several clinical criteria have been developed to standardize the diagnostic approach for patients with suspected PE. Computed tomographic pulmonary angiogram has significantly improved the detection of pulmonary embolism and is considered the imaging modality of choice to diagnose this disease. However, there are several potential pitfalls associated with this modality which can make diagnosis of PE challenging. In this review, we will discuss various pitfalls routinely encountered in the diagnostic work up of patients with suspected PE, approaches to mitigate these pitfalls and incidental pulmonary embolism.

OBJECTIVE. The purpose of this study is to evaluate the CT and clinical characteristics of in situ pulmonary artery thrombosis (PAT) associated with radiation therapy (RT). MATERIALS AND METHODS. A database search was performed to identify patients who had PAT develop after receiving RT. The CT characteristics of PAT, including the number, location, and appearance of filling defects as well as the presence of associated lung fibrosis, were recorded. The terminology (in situ thrombosis vs acute or chronic pulmonary embolism) used by the interpreting radiologists to describe PAT, the time between the completion of RT and development of PAT, the change in the size of the PAT, and observation of any new thrombi and emboli on follow-up imaging, were also recorded. RESULTS. Of the 27 patients in the study cohort, 22 (81%) had lung cancer and five (19%) had mesothelioma. Most PATs were solitary (93%) and nonocclusive (96%) and formed an obtuse angle to the vessel wall (89%). All PATs were eccentric within the involved PA and were located within the RT volume. The time from completion of RT to initial diagnosis of PAT on CT ranged from 53 to 2522 days (mean, 675 days). Radiation-induced lung fibrosis was present in the ipsilateral lung in all patients. No evidence of additional PA filling defects that suggested embolization were seen on follow-up images of any of the patients, even those who did not receive anticoagulant therapy. CONCLUSION. In situ PAT associated with RT, which to our knowledge has not previously been described in the English literature, has imaging features different from those of acute pulmonary emboli and does not appear to embolize. Radiologist awareness of PAT can facilitate accurate diagnosis and impact management.

ispartof: Mediastinum vol:6 pages:26- ispartof: location:China status: Published online

Imaging plays an essential role in the diagnosis and staging of pulmonary malignancy. Familiarity of less common manifestations of lung cancer including subsolid nodule, consolidation, and cyst associated lung cancer is important to avoid delayed diagnosis and improve patient outcomes. In this article, we review the staging of multifocal lung cancer, PET negative lung cancers (carcinoid and indolent lung adenocarcinoma), and false positive lymph nodes on PET due to infectious and inflammatory etiologies. Knowledge of these potential pitfalls and pearls in lung cancer imaging and correlation with patients’ clinical history are essential to prevent misinterpretation.

Whole body positron emission tomography (PET)/computed tomography (CT) imaging with [18F]-fluoro-2-deoxy-D-glucose (FDG) is widely used in oncologic imaging. In the chest, common PET/CT applications include the evaluation of solitary pulmonary nodules, cancer staging, assessment of response to therapy, and detection of residual or recurrent disease. Knowledge of the technical artifacts and potential pitfalls that radiologists may encounter in the interpretation of PET/CT in the thorax is important to avoid misinterpretation and optimize patient management. This article will review pitfalls in the interpretation of PET/CT in the chest related to technical factors, physiologic uptake, false positive findings, false negative findings, and iatrogenic conditions.

Hematopoietic stem cell transplantation (HSCT) is used in the treatment of various oncologic and hematologic diseases. After HSCT, patients are immunocompromised and are at risk for a wide variety of infectious and noninfectious complications. CT is routinely used when pulmonary complications are suspected after HSCT. In this article, we review the CT appearance of pulmonary complications that occur in the post-transplantation period with special emphasis on opportunistic infections, many of which are life-threatening.

Radiologic signs are often based on items or patterns that are encountered in everyday life. They are especially useful because their observation allows the differential diagnosis to be narrowed, and in some cases, enables a diagnosis to be made. In this review, several classic and newer computed tomography signs in the lungs are discussed.

Leukemias are malignancies in which abnormal white blood cells are produced in the bone marrow, resulting in compromise of normal bone marrow hematopoiesis and subsequent cytopenias. Leukemias are classified as myeloid or lymphoid depending on the type of abnormal cells produced and as acute or chronic according to cellular maturity. The four major types of leukemia are acute myeloid leukemia, chronic myeloid leukemia, acute lymphoblastic leukemia, and chronic lymphocytic leukemia. Clinical manifestations are due to either bone marrow suppression (anemia, thrombocytopenia, or neutropenia) or leukemic organ infiltration. Imaging manifestations of leukemia in the thorax are myriad. While lymphadenopathy is the most common manifestation of intrathoracic leukemia, leukemia may also involve the lungs, pleura, heart, and bones and soft tissues. Myeloid sarcomas occur in 5%-7% of patients with acute myeloid leukemia and represent masses of myeloid blast cells in an extramedullary location. ©RSNA, 2019.

In the imaging of the mediastinum, benign lesions mimicking malignancy constitute potential pitfalls in interpretation. Localization and characteristic imaging features are key to narrow the differential diagnosis and avoid potential pitfalls in interpretation. Based on certain anatomic landmarks, the mediastinal compartment model enables accurate localization. Depending on the anatomic origin, mediastinal lesions can have various etiologies. The anatomic location and structures contained within each mediastinal compartment are helpful in generating the differential diagnoses. These structures include thyroid, thymus, parathyroid, lymph nodes, pericardium, embryogenic remnants, and parts of the enteric tracts, vessels, and nerves. Imaging characteristics on computed tomography (CT), magnetic resonance imaging (MRI), and positron emission tomography-computed tomography (PET/CT), including attenuation (fluid, fat, calcification), contrast enhancement, and metabolic activity, aid in narrowing the differential diagnoses. Understanding the roles and limitations of various imaging modalities is helpful in the evaluation of mediastinal masses. In this review, we present potential pitfalls in the imaging of mediastinal lesions with emphasis on the mimics of malignancy.

Radiation therapy using conventional fractionated external-beam or high-precision dose techniques including three-dimensional conformal radiotherapy, stereotactic body radiation therapy, intensity-modulated radiation therapy, and proton therapy, is a key component in the treatment of patients with lung cancer. Knowledge of the radiation technique used, radiation treatment plan, expected temporal evolution of radiation-induced lung injury and patient-specific parameters, such as previous radiotherapy, concurrent chemoradiotherapy, and/or immunotherapy, is important in imaging interpretation. This review discusses factors that affect the development and severity of radiation-induced lung injury and its radiological manifestations with emphasis on the differences between conventional radiation and high-precision dose radiotherapy techniques.

Chest computed tomography (CT) is the modality of choice for mediastinal imaging. The high-resolution images provided by multi-detector CT result in routine visualization of normal anatomic structures, which can be confused with pathology. In addition, many mediastinal abnormalities are discovered incidentally, with a routine chest CT protocol which may be insufficient for definite diagnosis. Awareness of the spectrum of potential pitfalls of mediastinal imaging, artifacts related to flow, motion, and solutions to mitigate these problematic issues is important in accurate interpretation. The purpose of this review is to highlight and discuss potential pitfalls in the imaging of the mediastinum.

To evaluate the inter-observer consistency for subsolid pulmonary nodule radiomic features.Subsolid nodules were selected by reviewing radiology reports of CT examinations performed December 1, 2015 to April 1, 2016. Patients with CTs at two time points were included in this study. There were 55 patients with subsolid nodules, of whom 14 had two nodules. Of 69 subsolid nodules, 66 were persistent at the second time point, yielding 135 lesions for segmentation. Two thoracic radiologists and an imaging fellow segmented the lesions using a semi-automated volumetry algorithm (Syngo.via Vb20, Siemens). Coefficient of variation (CV) was used to assess consistency of 91 quantitative measures extracted from the subsolid nodule segmentations, including first and higher order texture features. The accuracy of segmentation was visually graded by an experienced thoracic radiologist. Influencing factors on radiomic feature consistency and segmentation accuracy were assessed using generalized estimating equation analyses and the Exact Mann-Whitney test.Mean patient age was 71 (38-93 years), with 39 women and 16 men. Mean nodule volume was 1.39mL, range .03-48.2mL, for 135 nodules. Several radiomic features showed high inter-reader consistency (CV5%), including entropy, uniformity, sphericity, and spherical disproportion. Descriptors such as surface area and energy had low consistency across inter-reader segmentations (CV10%). Nodule percent solid component and attenuation influenced inter-reader variability of some radiomic features. The presence of contrast did not significantly affect the consistency of subsolid nodule radiomic features. Near perfect segmentation, within 5% of actual nodule size, was achieved in 68% of segmentations, and very good segmentation, within 25% of actual nodule size, in 94%. Morphologic features including nodule margin and shape (each p0.01), and presence of air bronchograms (p = 0.004), bubble lucencies (p = 0.02) and broad pleural contact (p0.01) significantly affected the probability of near perfect segmentation. Stroke angle (p = 0.001) and length (p0.001) also significantly influenced probability of near perfect segmentation.The inter-observer consistency of radiomic features for subsolid pulmonary nodules varies, with high consistency for several features, including sphericity, spherical disproportion, and first and higher order entropy, and normalized non-uniformity. Nodule morphology influences the consistency of subsolid nodule radiomic features, and the accuracy of subsolid nodule segmentation.

Chondrosarcomas primarily originating in the mediastinal compartment are vanishingly rare. Contrary to other unusual tumors of the mediastinum, chondrosarcomas have been described in either anterior or posterior mediastinum. The histopathological spectrum that has been described in these mediastinal tumors is similar to that described in soft tissues. In our current practice, diagnostic imaging plays an important role before any of these neoplasms is rendered as of mediastinal origin. It is also important to highlight that even though a tumor may be presenting as a mediastinal tumor, such information in essence does not constitute that the tumor is not in fact associated with another structure within the thoracic cavity, thus the importance of strict radiological correlation. Furthermore, molecular characterization of tumors that in the past were coded under the spectrum of chondrosarcomas, are now believed to represent different tumoral conditions, which raises important issues in tumor classification. Therefore, in this review, we will outline a more specific criteria regarding the diagnosis of chondrosarcomas, as wells as the essentials in the histopathological assessment of these tumors. In addition, we will discuss the current knowledge of these entities as well as their differential diagnosis, which inevitably will depend on the anatomic distribution of the tumor—anterior or posterior compartment.

A significant reduction in lung cancer specific mortality rate was demonstrated by the National Lung Screening Trial (NLST) in participants who had annual low-dose computed tomography (LDCT) screening. In addition to early detection of lung cancer, lung cancer screening (LCS) provides an opportunity to detect cardiovascular disease, pulmonary disease (such as chronic obstructive pulmonary disease and interstitial lung disease), and extrapulmonary neoplasms, such as thyroid, breast, kidney, liver, esophageal, pancreatic and mediastinal tumors. Considering the fact that 22.3% of the certified deaths in the computed tomography (CT) arm of the NLST trial were due to extrapulmonary malignancies, compared to 22.9% of deaths from lung cancer, it is possible that early diagnosis and treatment of clinically significant incidental findings may further decrease morbidity and mortality in screening participants. In this article we review prevalence, clinical relevance and management of incidentally detected extrapulmonary malignancies.

The updated eighth edition of the tumor, node, metastasis (TNM) classification for lung cancer includes revisions to T and M descriptors. In terms of the M descriptor, the classification of intrathoracic metastatic disease as M1a is unchanged from TNM-7. Extrathoracic metastatic disease, which was classified as M1b in TNM-7, is now subdivided into M1b (single metastasis, single organ) and M1c (multiple metastases in one or multiple organs) descriptors. In this article, the rationale for changes in the M descriptors, the utility of preoperative staging with PET/computed tomography, and the treatment options available for patients with oligometastatic disease are discussed.

The number of screening-detected lung nodules is expected to increase as low-dose computed tomography screening is implemented nationally. Standardized guidelines for image acquisition, interpretation, and screen-detected nodule workup are essential to ensure a high standard of medical care and that lung cancer screening is implemented safely and cost effectively. In this article, we review the current guidelines for pulmonary nodule management in the lung cancer screening setting.

The treatment strategy in advanced non-small cell lung cancer (NSCLC) has evolved from empirical chemotherapy to a personalized approach based on histology and molecular markers of primary tumors. Targeted therapies are directed at the products of oncogenic driver mutations. Immunotherapy facilitates the recognition of cancer as foreign by the host immune system, stimulates the immune system, and alleviates the inhibition that allows the growth and spread of cancer cells. The authors describes the role of targeted therapy and immunotherapy in the treatment of NSCLC, patterns of disease present on imaging studies, and immune-related adverse events encountered with immunotherapy.

Lung cancer remains the leading cause of cancer-related mortality worldwide. To formulate effective treatment strategies and optimize patient outcomes, accurate staging is essential. Lung cancer staging has traditionally relied on a TNM staging system, for which the International Association for the Study of Lung Cancer (IASLC) has recently proposed changes. The revised classification for this eighth edition of the TNM staging system (TNM-8) is based on detailed analysis of a new large international database of lung cancer cases assembled by the IASLC for the purposes of this project. Fundamental changes incorporated into TNM-8 include (a) modifications to the T classification on the basis of 1-cm increments in tumor size; (b) grouping of lung cancers that result in partial or complete lung atelectasis or pneumonitis; (c) grouping of tumors with involvement of a main bronchus irrespective of distance from the carina; (d) reassignment of diaphragmatic invasion in terms of T classification; (e) elimination of mediastinal pleural invasion from the T classification; and (f) subdivision of the M classification into different descriptors on the basis of the number and site of extrathoracic metastases. In response to these revisions, established stage groups have been modified, and others have been created. In addition, recommendations for classifying patterns of disease that result in multiple sites of pulmonary involvement, including multiple primary lung cancers, lung cancers with separate tumor nodules, multiple ground-glass/lepidic lesions, and consolidation, as well as recommendations for lesion measurement, are addressed. Understanding the key revisions introduced in TNM-8 allows radiologists to accurately stage patients with lung cancer and optimize therapy.

Pulmonary and pleural metastases are routinely identified on thoracic computed tomography. Pulmonary metastases are the most common pulmonary neoplasms and commonly originate from primary malignancies of the lung, breast, colon, pancreas, stomach, skin (ie, melanoma), head and neck, and kidney. Metastatic disease to the lungs may occur via 3 routes of spread: hematogenous, lymphatic, and endobronchial. Pleural metastases most commonly originate from primary malignancies of the lung and breast. Mechanisms of pleural metastatic involvement include hematogenous spread, direct invasion from a neighboring tumor, and retrograde lymphatic spread from the mediastinum. Awareness of the spectrum of appearances of metatastic disease in the chest is important in avoiding misinterpretation.

Non-small cell lung cancer (NSCLC) is usually diagnosed when it is not amenable to curative surgery or radiation. Many of these patients are candidates for systemic therapy. Median survival is only approximately 10 months, and, accordingly, treatment in advanced NSCLC is evolving toward a more personalized approach with the identification of genetic abnormalities based on biomarkers. For example, gene mutations in EGFR (epidermal growth factor receptor) and ALK (anaplastic lymphoma kinase) lead to a cascade of pathways resulting in uncontrolled growth, proliferation, and survival of tumor cells. Targeted therapies are aimed at the products of these mutated genes and include agents such as erlotinib and gefitinib (in EGFR-mutant NSCLC) or crizotinib (in ALK-positive NSCLC). Antiangiogenesis agents such as bevacizumab are another category of targeted therapy that inhibits vascular endothelial growth factors. The imaging characteristics of advanced NSCLC with genetic abnormalities, the evolution of targeted therapies and their imaging manifestations will be discussed.

18F-fluorodeoxryglucose (18F-FDG) PET/CT imaging is routinely performed in the evaluation of patients with known or suspected thoracic malignancy. Indications for its use include staging of malignancy, assessment of response to therapy, evaluation of suspected disease recurrence, and evaluation of a solitary pulmonary nodule. In this article, we will discuss specific technical artifacts and also review potential pitfalls in the interpretation of PET/CT in thoracic malignancies including normal variations in physiologic uptake of FDG, benign conditions (such as infection, inflammation, posttreatment changes, and iatrogenic factors) that can result in increased FDG uptake, and malignancies that demonstrate scarce to no FDG uptake.

Lung cancer remains the most common cause of cancer death in the United States of America and worldwide despite continued advances in lung cancer screening as well as surgical, medical, and radiation oncological treatments. Adenocarcinoma is the most common histological subtype of primary lung cancer and has recently been reorganized into a spectrum ranging from preinvasive lesions to invasive adenocarcinoma. An understanding of the pathology, diagnosis, and management of the spectrum of lung adenocarcinoma is more important than ever, considering the central role of the radiologist. The aim of this review is to describe the subtypes of the lung adenocarcinoma spectrum in terms of histological and imaging features, their pattern of growth on imaging, management, staging, and evolving knowledge of tumor genetics.

Computed tomography pulmonary angiography (CTPA) has become the primary imaging modality for evaluating the pulmonary arteries. Although pulmonary embolism is the primary indication for CTPA, various pulmonary vascular abnormalities can be detected in adults. Knowledge of these disease entities and understanding technical pitfalls that can occur when performing CTPA are essential to enable accurate diagnosis and allow timely management. This review will cover a spectrum of acquired abnormalities including pulmonary embolism due to thrombus and foreign bodies, primary and metastatic tumor involving the pulmonary arteries, pulmonary hypertension, as well as pulmonary artery aneurysms and stenoses. Additionally, methods to overcome technical pitfalls and interventional treatment options will be addressed.

Eosinophilic lung diseases encompass a broad range of conditions wherein patients present with pulmonary opacities and eosinophilia of the serum, pulmonary tissue, or bronchoalveolar lavage fluid. Many of these entities can be idiopathic or are secondary to parasitic infection, exposure to drugs, toxins, or radiation. These diseases exhibit a wide range of imaging findings, including consolidation, ground-glass opacities, nodules, and masses. Diagnoses often require bronchoalveolar lavage and/or biopsy to confirm respiratory eosinophilia and to exclude other entities, such as infection or malignancy. Treatment entails administration of corticosteroids, removal of inciting agents, and treatment of underlying infection.

Dual-energy CT (DECT) is an emerging technology that has potential to enhance diagnostic performance and radiologists' confidence in the evaluation of thoracic malignancies. DECT clinical applications include characterization of solitary pulmonary nodule, lung masses and mediastinal tumors. DECT-derived iodine uptake quantification may assist in characterization of tumor differentiation and gene expression. The use DECT in oncology has potential to improve lung cancer staging, therapy planning, and assessment of response to therapy as well as detection of incidental pulmonary embolism.