Radiol Clin N Am 43 (2005) xi Preface Essentials of Thoracic Imaging Caroline Chiles, MD Guest Editor Diagnostic radiology, like many other medical amount of current literature in thoracic radiology to specialties, does not allow physicians to maintain the application of new technologies to bread-and- competence solely on the basis of accumulating ex- butter cases. Thank you to my colleagues who have perience, but requires a commitment to life–long shared their expertise in the basics of thoracic imag- learning. Keeping pace with new knowledge and ing: lung cancer, metastatic disease, the solitary pul- new technology competes with clinical demands on monary nodule, pneumonia, cardiovascular disease, a radiologist’s time. At the 2002 annual meeting in and high resolution CT. Thank you as well to Ron Chicago, the Radiological Society of North America Zagoria, who included me in the initial Radiological initiated a series of continuing medical education Society of North America Essentials faculty, and to lectures called bThe Essentials.Q Attendance and Barton Dudlick, who saw this project through from audience feedback surpassed all expectations. Sur- start to finish. veys of radiologists attending bThe EssentialsQ lectures showed an equal mix of general radiologists, Caroline Chiles, MD and radiologists who practice subspecialties outside Division of Radiological Sciences the lecture topic. The participants were seeking prac- Department of Radiology tical information that would impact their daily radiol- Wake Forest University School of Medicine ogy work—applying new technologies to diseases Medical Center Boulevard that are encountered every day. Winston-Salem, NC 27157-1088, USA My goal for this issue of Radiologic Clinics of E-mail address: [email protected] North America is to condense the overwhelming 0033-8389/05/$ – see front matter D 2005 Elsevier Inc. All rights reserved. doi:10.1016/j.rcl.2005.03.001 radiologic.theclinics.com Radiol Clin N Am 43 (2005) 467 – 480 Imaging of Non–Small Cell Lung Cancer Reginald F. Munden, MD, DMD*, John Bruzzi, MD Division of Diagnostic Imaging, Department of Radiology, The University of Texas MD Anderson Cancer Center, 1515 Holcombe Boulevard, Houston, TX 77030, USA Lung cancer is the most common type of cancer assessing treatment effects and complications. This and the leading cause of cancer deaths in the United article discusses the imaging in patients with NSCLC States for both men and women. It was estimated that and its use in caring for these patients. 173,770 new cases and 160,440 deaths from lung cancer would occur in 2004 [1]. More Americans die of lung cancer than of colorectal, breast, and prostate Importance of staging lung cancer cancers combined, which are the second through fourth leading causes of cancer mortality, respec- Because surgical resection of lung cancer offers tively. Even though major efforts at improving sur- the best chance of cure, accurate staging is important vival have occurred over the years, the overall 5-year to determine if patients are surgical candidates. In survival of lung cancer remains dismal at 14% for all general, clinical stage I, II, and some stage IIIA pa- stages (clinical staging), 61% for stage IA, 38% tients are considered to have disease that is resectable, for stage IB, 34% for stage IIA, 24% for stage IIB, whereas more extensive disease as in some patients 13% for stage IIIA, 5% for stage IIIB, and 1% for with stage IIIA and most with stage IIIB and IV is stage IV [2]. treated with radiation therapy, chemotherapy, or a Once lung cancer has been established, the Inter- combination of both [4]. More than 60% of patients national System for Staging Lung Cancer is used to with lung cancer receive radiotherapy at some point stage newly diagnosed non–small cell lung cancer in their disease, 17% of which is for palliation [5]. (NSCLC). This system describes the extent of Patients with early stage disease (stage I–II) who are NSCLC in terms of the size, location, and extent of not surgical candidates because of medical comor- the primary tumor (T descriptor); the presence and bidities or who refuse surgery may undergo radio- location of lymph node involvement (N descriptor); therapy with curative intent [6]. Radiotherapy may and the presence or absence of distant metastatic also be used as preoperative concurrent chemo- disease (M descriptor) [2]. Radiologic evaluation is radiotherapy in locally advanced lung cancer to an important component of the clinical staging ‘‘downstage’’ the patient to a lower stage and make evaluation and can greatly influence whether the them a candidate for surgical cure. Preliminary patient is treated with surgical resection, radiation studies suggest this technique may have a role in therapy, chemotherapy, or a combination of these treating NSCLC, but remains controversial [7]. For modalities [3]. In addition to staging, the radiologic locally advanced and inoperable lung cancer, chemo- evaluation of the patient undergoing treatment and therapy is used in conjunction with radiation therapy subsequent follow-up is important to the clinician for to improve survival [8–10]. Chemotherapy alone is used in stage III and IV NSCLC patients who are not candidates for surgery or chemoradiation. * Corresponding author. Because the determination of disease extent is E-mail address: [email protected] often based on clinical staging, imaging studies and (R.F. Munden). the radiologist’s interpretation are very important 0033-8389/05/$ – see front matter D 2005 Elsevier Inc. All rights reserved. doi:10.1016/j.rcl.2005.01.009 radiologic.theclinics.com 468 munden & bruzzi aspects of the treatment plan decision between surgery, radiation therapy, chemotherapy, or a combi- nation of treatments. Common imaging modalities for staging lung cancer are chest radiographs, CT, MR imaging, positron-emission tomography (PET), and fused PET-CT. Although a common method of detecting lung cancer, chest radiographs are of lim- ited value in staging lung cancer. The most common radiologic examination in the lung cancer patient is chest CT [11] because of its ability to provide anatomic information regarding the primary tumor and evaluate the extent of intrathoracic and regional extrathoracic disease. Whole-body PET using fluorine- 18–fluorodeoxyglucose (18F-FDG) has become a Fig. 1. A 60-year-old man with T2 non–small cell lung very useful tool in staging lung cancer; fused PET– cancer. Axial image from a contrast-enhanced CT scan shows that the primary tumor is located centrally (arrow), CT imaging is a newer technique that has further causing distal postobstructive atelectasis. Note the difficulty improved staging [3,12,13]. of differentiating tumor from collapsed lung parenchyma. Staging The sensitivity and specificity of CT in determining chest wall invasion is reported to vary from 38% to The radiologic evaluation of the primary tumor 87% and 40% to 90%, respectively [16]. Glazer et al (T descriptor) should describe the size, location, mar- [17] reported CT to have 87% sensitivity, 59% speci- gins, and relationship to adjacent structures for the ficity, and 68% accuracy for assessing chest wall surgeon, radiation oncologist, or medical oncologist invasion; however, local chest pain was more specific to determine an appropriate treatment plan. T1 tumors (94%) and accurate (85%). MR imaging sensitivity are technically the easiest to resect because they are and specificity (63%–90% and 84%–86%, respec- smaller (< 3 cm) and are limited to the lung paren- tively) in diagnosing chest wall invasion are similar chyma. T1 tumors are surrounded by lung paren- to those of CT [16,18,19]. Even though radiologic chyma but may reside near other structures that are evaluation for chest wall invasion is somewhat limi- important to note. As an example, tumors adjacent to ted, at times definite invasion can be determined, and pulmonary vessels may require a change in surgical important to note for treatment planning. Likewise, technique or radiotherapy treatment plan. if invasion is not definite, this uncertainty should also T2 tumors are larger ( 3 cm), but should not be be noted. closer than 2 cm to the carina and may have asso- Invasion of the primary tumor into the medias- ciated atelectasis or pneumonitis that does not include tinum is also important to assess. As in chest wall the entire lobe (Fig. 1). As with T1 tumors, the ana- invasion, CT and MR imaging can be accurate tomic relationship of the tumor to nearby structures (56%–89% and 50%–93%, respectively) for con- may influence the treatment plan and should be firming gross invasion of the mediastinum [20–22], reported. For instance, if the lobar bronchus or main but have limited accuracy when invasion is subtle. bronchus is involved by tumor, a sleeve resection or Definite invasion, however, should be reported. pneumonectomy may be required [14]. Associated Improvement in determining the extent of chest wall atelectasis is important because it may require an or mediastinal invasion by the primary tumor using alteration in the radiotherapy treatment plan. PET and PET–CT has not been reported. T3 tumors can be any size; invade the chest wall, T4 tumors involve the mediastinum, heart, great diaphragm, mediastinal pleura, parietal pericardium, vessels, trachea, esophagus, vertebral body, carina, or be within 2 cm of the carina; or have associated or have a malignant pleural or pericardial effusion atelectasis or pneumonitis of the entire lobe. Appro- (Fig. 2). If the patients have no other contraindication priate description of location is important because if to surgery, some of these tumors represent the one the tumor is less than 2 cm from the carina, a carinal subset within clinical stage IIIB patients who remain pneumonectomy needs to be performed [15]. The good candidates for surgery [23]. Surgical resection extent of chest wall invasion is also important to of selected tumors involving the left atrium, great convey because more extensive surgical techniques vessels, superior vena cava, vertebral body, trachea, or larger radiotherapy treatment plans are required.