- Email: [email protected]
Endosonography for Lung Cancer Staging
CHEST Endosonography for Lung Cancer Staging One Scope Fits All? cancer staging methodology has evolved Lung dramatically over the past years, and transeso-
phageal endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA) in particular has emerged as a valuable diagnostic technique for mediastinal staging.1 Its particular strength lies in the detection of lymph nodes in the lower mediastinum and the aortopulmonary window while the pretracheal and hilar nodes are out of reach because of the interposition of air from the large airways. So far, EUS-FNA is performed with ultrasound endoscopes developed primarily for gastroenterologists. The required acquisition of this special equipment likely represents one of the barriers for the implementation of endoscopic ultrasound (EUS) in non-small cell lung cancer (NSCLC) staging in the pulmonary community. Mediastinal nodes also can be accurately sampled under ultrasound guidance from the airways (endobronchial ultrasound-guided transbronchial needle aspiration [EBUS-TBNA]).2 This technique is ideally suited to detect pretracheal and hilar nodes. Conceptually, combined EUS and endobronchial ultrasound (EBUS) investigation should enable virtually a complete evaluation of the mediastinum because of the complementary reach of different nodes for each technique. Accurate staging of NSCLC is critically important for assessing the extent of the tumor and planning optimal treatment. Both EUS-FNA and EBUS-TBNA are incorporated in recent lung cancer staging guidelines as a minimally invasive alternative for surgical staging to detect, but not exclude, nodal metastases.3,4 EUS-FNA added to mediastinoscopy5 or EBUS-TBNA6,7 improves preoperative staging of NSCLC and, therefore, reduces futile thoracotomies. In this issue of CHEST, Hwangbo et al8 (see page 795) and Herth et al9 (see page 790) report on complete endosonographic staging of NSCLC using just a single EBUS scope to perform both EBUS and EUS. Hwangbo and colleagues investigated 150 patients with potentially operable (suspected) NSCLC with www.chestpubs.org
Editorials CHEST | Volume 138 | Number 4 | October 2010
an EBUS-TBNA bronchoscope immediately followed by a transesophageal investigation (EUS-FNA) using the same EBUS scope. For this evaluation of mediastinal nodes from the esophagus using the EBUS scope, the abbreviation EUS-B-FNA (endoscopic ultrasound with bronchoscope-guided fine-needle aspiration) was introduced by Hwangbo et al.8 In this study, EUS-B-FNA was used as an add-on to EBUS only for those patients in whom nodes were inaccessible or difficult to reach by EBUS. Therefore, unlike EBUS, no standardized evaluation of the mediastinal nodes was performed during the EUS investigation, which was likely reflected in the very different time periods used for each procedure (mean, 18.9 min vs 3.8 min for EBUS and EUS, respectively). The addition of EUS to EBUS resulted in the detection of three (7%) more patients with mediastinal metastases. Sensitivity and negative predictive value regarding mediastinal staging of EBUS alone vs the combined approach were 84% vs 91% and 93% vs 96%, respectively. As expected, EUS-B-FNA proved specifically useful for tissue sampling of nodes located paratracheally to the left (station 4L), the aortopulmonary window (station 5), and the nodes located in the lower mediastinum (stations 8 and 9). This single-center study was performed over 6 months in consecutive patients with (suspected) lung cancer with an indication of mediastinal tissue staging after CT scans and PET scans and used surgery as the reference standard for the absence of mediastinal metastases after endosonography. Herth and coworkers,9 curiously, also investigated 150 patients with (suspected) NSCLC using only the EBUS scope for a systematic investigation of all mediastinal nodes that can be reached from the airways as well as the esophagus. EBUS-TBNA identified 65 (91%) of 71 patients with mediastinal nodal metastases, whereas bronchoscope-guided EUS-FNA identified 63 (89%) and the combination of both identified 68 (96%). Sensitivity and negative predictive values for EBUS-TBNA and bronchoscope-guided EUS-FNA and the combined approach were 91% and 92%, 89% and 82%, 96% and 96%, respectively. A significant bias regarding patient selection seems likely in this investigation because the inclusion of 150 consecutive CHEST / 138 / 4 / OCTOBER, 2010
Downloaded from chestjournal.chestpubs.org by Kimberly Henricks on October 7, 2010 © 2010 American College of Chest Physicians
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patients from three large centers took 3 years. Additionally, the role of CT scans and PET scans in the workup is largely unclear, and a surgical reference standard was not available in all the patients, which theoretically might be a bias favoring improved outcome of endosonography. The important question, however, is how should these findings with the single EBUS scope approach be interpreted and translated into advice for clinical practice? The outcomes for the assessment of nodal staging in the studies by Hwangbo8 and Herth et al9 are remarkably similar to previous studies using conventional EUS scopes.6,7,10 Do these data imply that the “poor man’s” version of an EUS investigation performed with an EBUS scope will replace the conventional EUS equipment for lung cancer staging? Conventional EUS is very well tolerated by patients, and how patients perceive the various endoscopies under mild sedation is important in this discussion. Unlike EBUS, patients undergoing EUS rarely cough or experience shortness of breath. Additionally, the absence of cartilage rings makes the biopsy of lesions easier, especially in small nodes. Many pulmonologists who have access to both conventional EUS and EBUS have a preference for EUS above EBUS for these reasons mentioned, especially in patients with COPD. Regardless of the type of scope used, EUS investigators should be aware of indications and contraindications to EUS and should be adequately trained in mediastinal EUS. For a clear interpretation of the location of various nodes with EUS, knowledge of their anatomic relation with the various vascular structures is essential.11 With dedicated training, however, pulmonologists can implement EUS successfully.12 The potential advantages for performing EUS with an EBUS scope are manyfold. Only one ultrasound scope is needed, which significantly reduces initial investment, operating costs, and investigating time. Several limitations apply regarding the performance of EUS with an EBUS scope. First, both scanning range (70° vs 120°-180°) and penetration depth are markedly decreased, and ultrasound quality of EUS with an EBUS scope is inferior to that of conventional EUS. Consequently, the anatomic orientation in the mediastinum and visualization of paraesophageal lesions are inferior. Second, in our experience, the actual aspiration of nodes is more difficult with the relatively small scope in the esophagus compared with the stability of conventional EUS equipment. Third, the left adrenal gland (a predilection site for distant metastases) is more difficult to reach by EBUS scopes, even in the hands of experienced investigators. Do the limitations of EUS with EBUS scopes justify, then, the investment in a separate EUS scope? To address this question, it is important to determine
whether EUS will be used only in selected patients as an add-on to EBUS (as in the Hwangbo et al8 study) or as the minimally invasive staging test of choice (preferred above EBUS) if the target nodes are located within its reach. For the position of endosonography in novel lung cancer staging algorithms, publication of the various trials comparing endosonography with surgical staging is awaited (Assessment of Surgical Staging vs. Endoscopic Ultrasound in Lung Cancer: a Randomized Clinical Trial (ASTER Study) [Trial registration: clinicaltrials.gov; Identifier: NCT00432640]; Study Comparing EBUS & EUS to Mediastinoscopy in Staging and Detection of Lung Cancer [Trial registration: clinicaltrials.gov; Identifier: NCT00970645]; Minimally Invasive, Diagnosis and Staging of Lung Cancer: A Prospective Head-to-Head Comparison With Traditional Gold Standard Techniques [Trial registration: clinicaltrials.gov; Identifier: NCT01011595]). In conclusion, it is clear that endosonography improves lung cancer staging. EUS and EBUS combined are better than each technique alone due to the complementary reach of different mediastinal nodes. With EUS, nodes located paratracheally on the right will be missed, with EBUS nodes in the lower mediastinum and the aortopulmonary window. The present studies from different parts of the world have a clear practical message: If only an EBUS scope is available for the detection of mediastinal nodes, a transesophageal (EUS) investigation should be performed with it as well in order to improve preoperative tumor staging. That said, we still believe that a dedicated EUS scope has additional benefit and should be part of a complete diagnostic unit. Jouke T. Annema, MD, PhD Klaus F. Rabe, MD, PhD Leiden, The Netherlands Affiliations: From the Department of Pulmonology, Leiden University Medical Center. Financial/nonfinancial disclosures: The authors have reported to CHEST that no potential conflicts of interest exist with any companies/organizations whose products or services may be discussed in this article. Correspondence to: Jouke T. Annema, MD, PhD, Leiden University Medical Center, Department of Pulmonology C3-P, Albinusdreef 2, 2300 RC, Leiden, The Netherlands; e-mail: [email protected] © 2010 American College of Chest Physicians. Reproduction of this article is prohibited without written permission from the American College of Chest Physicians (http://www.chestpubs.org/ site/misc/reprints.xhtml). DOI: 10.1378/chest.10-0955
References 1. Micames CG, McCrory DC, Pavey DA, Jowell PS, Gress FG. Endoscopic ultrasound-guided fine-needle aspiration for non-small cell lung cancer staging: A systematic review and metaanalysis. Chest. 2007;131(2):539-548. 2. Gu P, Zhao Y Z, Jiang LY, Zhang W, Xin Y, Han BH. Endobronchial ultrasound-guided transbronchial needle aspiration
766
Editorials
Downloaded from chestjournal.chestpubs.org by Kimberly Henricks on October 7, 2010 © 2010 American College of Chest Physicians
3. 4.
5. 6.
7. 8.
9.
10.
11.
12.
for staging of lung cancer: a systematic review and meta-analysis. Eur J Cancer. 2009;45(8):1389-1396. De Leyn P, Lardinois D, Van Schil PE, et al. ESTS guidelines for preoperative lymph node staging for non-small cell lung cancer. Eur J Cardiothorac Surg. 2007;32(1):1-8. Detterbeck FC, Jantz MA, Wallace M, Vansteenkiste J, Silvestri GA; American College of Chest Physicians. Invasive mediastinal staging of lung cancer: ACCP evidence-based clinical practice guidelines (2nd edition). Chest. 2007;132 (3 Suppl): 202S-220S. Annema JT, Versteegh MI, Veseliç M, et al. Endoscopic ultrasound added to mediastinoscopy for preoperative staging of patients with lung cancer. JAMA. 2005;294(8):931-936. Vilmann P, Krasnik M, Larsen SS, Jacobsen GK, Clementsen P. Transesophageal endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA) and endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) biopsy: a combined approach in the evaluation of mediastinal lesions. Endoscopy. 2005;37(9):833-839. Wallace MB, Pascual JM, Raimondo M, et al. Minimally invasive endoscopic staging of suspected lung cancer. JAMA. 2008;299(5):540-546. Hwangbo B, Lee G-K, Lee HS, et al. Transbronchial and transesophageal fine-needle aspiration using an ultrasound bronchoscope in mediastinal staging of potentially operable lung cancer. Chest. 2010;138(4):795-802. Herth FJF, Krasnik M, Kahn N, Eberhardt R, Ernst A. Combined endoscopic-endobronchial ultrasound-guided, fine-needle aspiration of mediastinal lymph nodes through a single bronchoscope in 150 patients with suspected lung cancer. Chest. 2010;138(4):790-794. Rintoul RC, Skwarski KM, Murchison JT, Hill A, Walker WS, Penman ID. Endoscopic and endobronchial ultrasound realtime fine-needle aspiration for staging of the mediastinum in lung cancer. Chest. 2004;126(6):2020-2022. Tournoy KG , Annema JT, Krasnik M, Herth FJ, van Meerbeeck JP. Endoscopic and endobronchial ultrasonography according to the proposed lymph node map definition in the seventh edition of the tumor, node, metastasis classification for lung cancer. J Thorac Oncol. 2009;4(12): 1576-1584. Annema JT, Bohoslavsky R, Burgers S, et al. Implementation of endoscopic ultrasound for lung cancer staging. Gastrointest Endosc. 2010;71(1):64-70.
Viral Community-Acquired Pneumonia If We Do Not Diagnose It and Do Not Treat It, Can It Still Hurt Us? are a generally neglected cause of communityViruses acquired pneumonia (CAP) for a number of
understandable reasons. They are included in investigational and epidemiologic studies, but are not routinely sought in clinical practice because they are difficult to diagnose, primarily because the methods used for this purpose (culture, immunofluorescence for viral antigens, and serology) are expensive and often unavailable, and the results do not become known in a timely manner. In addition, there are few www.chestpubs.org
available antiviral agents, and when these are used therapeutically, they are not as rapidly and clinically effective as we have come to expect from antibacterial therapies. However, viral epidemics do attract our attention, as became clear with Hantavirus in New Mexico in 1993, Severe Acute Respiratory Syndrome (SARS)associated coronavirus in Asia in 2003, and novel 2009 influenza A(H1N1) [A(H1N1)] worldwide in 2009. In the latter instance, we appreciated the important clinical role of this pathogen, which could lead to nonpneumonic lower respiratory tract infection (tracheobronchitis), viral pneumonia (often with acute lung injury), secondary bacterial pneumonia, and probably asymptomatic colonization and carriage.1 The severity of the infection with the novel A(H1N1) in patients of all ages, and not just the elderly as in seasonal influenza, made us pay attention, and we all became familiar with nucleic acid amplification testing (NAAT) methods for definitive diagnosis as we sought new strategies for therapy. Compelling reasons for establishing a definitive diagnosis of epidemic viral infection, even in the absence of optimal therapy, were to identify infected patients so that they could be effectively isolated and also to identify noninfected patients so that they could be removed from isolation when they had a clinical presentation of a lower respiratory tract infection. Viruses are recognized as a common cause of CAP, yet little attention is paid to these organisms in clinical practice because of the diagnostic and therapeutic limitations discussed above. Although influenza remains the predominant viral cause of CAP in adults, the American Thoracic SocietyⲐInfectious Diseases Society of America guidelines for CAP includes other commonly recognized viruses such as respiratory syncytial virus (RSV), adenovirus, and parainfluenza virus, as well as less common viruses, including human metapneumovirus, herpes simplex virus, varicella-zoster virus, SARS-associated coronavirus, and measles virus.2 In studies of CAP from Spain and Chile, using immunofluorescent antigen detection methods, the incidence of CAP caused by viral infection in immune-competent individuals has varied from 18% to 32%, and in the Chilean study, viral pneumonia was particularly common in elderly patients.3,4 Interestingly, in the Chilean study, pure viral infection was present in 23% of patients with CAP, and was more commonly found in patients receiving outpatient antimicrobials, implying that many of these patients may have had bacterial coinfection, but that the bacterial component was eliminated by the use of antibiotics before hospitalization.3 The incidence of viral CAP can be as high as 56% when outpatients are included and when NAAT testing is used.5 CHEST / 138 / 4 / OCTOBER, 2010
Downloaded from chestjournal.chestpubs.org by Kimberly Henricks on October 7, 2010 © 2010 American College of Chest Physicians
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phageal endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA) in particular has emerged as a valuable diagnostic technique for mediastinal staging.1 Its particular strength lies in the detection of lymph nodes in the lower mediastinum and the aortopulmonary window while the pretracheal and hilar nodes are out of reach because of the interposition of air from the large airways. So far, EUS-FNA is performed with ultrasound endoscopes developed primarily for gastroenterologists. The required acquisition of this special equipment likely represents one of the barriers for the implementation of endoscopic ultrasound (EUS) in non-small cell lung cancer (NSCLC) staging in the pulmonary community. Mediastinal nodes also can be accurately sampled under ultrasound guidance from the airways (endobronchial ultrasound-guided transbronchial needle aspiration [EBUS-TBNA]).2 This technique is ideally suited to detect pretracheal and hilar nodes. Conceptually, combined EUS and endobronchial ultrasound (EBUS) investigation should enable virtually a complete evaluation of the mediastinum because of the complementary reach of different nodes for each technique. Accurate staging of NSCLC is critically important for assessing the extent of the tumor and planning optimal treatment. Both EUS-FNA and EBUS-TBNA are incorporated in recent lung cancer staging guidelines as a minimally invasive alternative for surgical staging to detect, but not exclude, nodal metastases.3,4 EUS-FNA added to mediastinoscopy5 or EBUS-TBNA6,7 improves preoperative staging of NSCLC and, therefore, reduces futile thoracotomies. In this issue of CHEST, Hwangbo et al8 (see page 795) and Herth et al9 (see page 790) report on complete endosonographic staging of NSCLC using just a single EBUS scope to perform both EBUS and EUS. Hwangbo and colleagues investigated 150 patients with potentially operable (suspected) NSCLC with www.chestpubs.org
Editorials CHEST | Volume 138 | Number 4 | October 2010
an EBUS-TBNA bronchoscope immediately followed by a transesophageal investigation (EUS-FNA) using the same EBUS scope. For this evaluation of mediastinal nodes from the esophagus using the EBUS scope, the abbreviation EUS-B-FNA (endoscopic ultrasound with bronchoscope-guided fine-needle aspiration) was introduced by Hwangbo et al.8 In this study, EUS-B-FNA was used as an add-on to EBUS only for those patients in whom nodes were inaccessible or difficult to reach by EBUS. Therefore, unlike EBUS, no standardized evaluation of the mediastinal nodes was performed during the EUS investigation, which was likely reflected in the very different time periods used for each procedure (mean, 18.9 min vs 3.8 min for EBUS and EUS, respectively). The addition of EUS to EBUS resulted in the detection of three (7%) more patients with mediastinal metastases. Sensitivity and negative predictive value regarding mediastinal staging of EBUS alone vs the combined approach were 84% vs 91% and 93% vs 96%, respectively. As expected, EUS-B-FNA proved specifically useful for tissue sampling of nodes located paratracheally to the left (station 4L), the aortopulmonary window (station 5), and the nodes located in the lower mediastinum (stations 8 and 9). This single-center study was performed over 6 months in consecutive patients with (suspected) lung cancer with an indication of mediastinal tissue staging after CT scans and PET scans and used surgery as the reference standard for the absence of mediastinal metastases after endosonography. Herth and coworkers,9 curiously, also investigated 150 patients with (suspected) NSCLC using only the EBUS scope for a systematic investigation of all mediastinal nodes that can be reached from the airways as well as the esophagus. EBUS-TBNA identified 65 (91%) of 71 patients with mediastinal nodal metastases, whereas bronchoscope-guided EUS-FNA identified 63 (89%) and the combination of both identified 68 (96%). Sensitivity and negative predictive values for EBUS-TBNA and bronchoscope-guided EUS-FNA and the combined approach were 91% and 92%, 89% and 82%, 96% and 96%, respectively. A significant bias regarding patient selection seems likely in this investigation because the inclusion of 150 consecutive CHEST / 138 / 4 / OCTOBER, 2010
Downloaded from chestjournal.chestpubs.org by Kimberly Henricks on October 7, 2010 © 2010 American College of Chest Physicians
765
patients from three large centers took 3 years. Additionally, the role of CT scans and PET scans in the workup is largely unclear, and a surgical reference standard was not available in all the patients, which theoretically might be a bias favoring improved outcome of endosonography. The important question, however, is how should these findings with the single EBUS scope approach be interpreted and translated into advice for clinical practice? The outcomes for the assessment of nodal staging in the studies by Hwangbo8 and Herth et al9 are remarkably similar to previous studies using conventional EUS scopes.6,7,10 Do these data imply that the “poor man’s” version of an EUS investigation performed with an EBUS scope will replace the conventional EUS equipment for lung cancer staging? Conventional EUS is very well tolerated by patients, and how patients perceive the various endoscopies under mild sedation is important in this discussion. Unlike EBUS, patients undergoing EUS rarely cough or experience shortness of breath. Additionally, the absence of cartilage rings makes the biopsy of lesions easier, especially in small nodes. Many pulmonologists who have access to both conventional EUS and EBUS have a preference for EUS above EBUS for these reasons mentioned, especially in patients with COPD. Regardless of the type of scope used, EUS investigators should be aware of indications and contraindications to EUS and should be adequately trained in mediastinal EUS. For a clear interpretation of the location of various nodes with EUS, knowledge of their anatomic relation with the various vascular structures is essential.11 With dedicated training, however, pulmonologists can implement EUS successfully.12 The potential advantages for performing EUS with an EBUS scope are manyfold. Only one ultrasound scope is needed, which significantly reduces initial investment, operating costs, and investigating time. Several limitations apply regarding the performance of EUS with an EBUS scope. First, both scanning range (70° vs 120°-180°) and penetration depth are markedly decreased, and ultrasound quality of EUS with an EBUS scope is inferior to that of conventional EUS. Consequently, the anatomic orientation in the mediastinum and visualization of paraesophageal lesions are inferior. Second, in our experience, the actual aspiration of nodes is more difficult with the relatively small scope in the esophagus compared with the stability of conventional EUS equipment. Third, the left adrenal gland (a predilection site for distant metastases) is more difficult to reach by EBUS scopes, even in the hands of experienced investigators. Do the limitations of EUS with EBUS scopes justify, then, the investment in a separate EUS scope? To address this question, it is important to determine
whether EUS will be used only in selected patients as an add-on to EBUS (as in the Hwangbo et al8 study) or as the minimally invasive staging test of choice (preferred above EBUS) if the target nodes are located within its reach. For the position of endosonography in novel lung cancer staging algorithms, publication of the various trials comparing endosonography with surgical staging is awaited (Assessment of Surgical Staging vs. Endoscopic Ultrasound in Lung Cancer: a Randomized Clinical Trial (ASTER Study) [Trial registration: clinicaltrials.gov; Identifier: NCT00432640]; Study Comparing EBUS & EUS to Mediastinoscopy in Staging and Detection of Lung Cancer [Trial registration: clinicaltrials.gov; Identifier: NCT00970645]; Minimally Invasive, Diagnosis and Staging of Lung Cancer: A Prospective Head-to-Head Comparison With Traditional Gold Standard Techniques [Trial registration: clinicaltrials.gov; Identifier: NCT01011595]). In conclusion, it is clear that endosonography improves lung cancer staging. EUS and EBUS combined are better than each technique alone due to the complementary reach of different mediastinal nodes. With EUS, nodes located paratracheally on the right will be missed, with EBUS nodes in the lower mediastinum and the aortopulmonary window. The present studies from different parts of the world have a clear practical message: If only an EBUS scope is available for the detection of mediastinal nodes, a transesophageal (EUS) investigation should be performed with it as well in order to improve preoperative tumor staging. That said, we still believe that a dedicated EUS scope has additional benefit and should be part of a complete diagnostic unit. Jouke T. Annema, MD, PhD Klaus F. Rabe, MD, PhD Leiden, The Netherlands Affiliations: From the Department of Pulmonology, Leiden University Medical Center. Financial/nonfinancial disclosures: The authors have reported to CHEST that no potential conflicts of interest exist with any companies/organizations whose products or services may be discussed in this article. Correspondence to: Jouke T. Annema, MD, PhD, Leiden University Medical Center, Department of Pulmonology C3-P, Albinusdreef 2, 2300 RC, Leiden, The Netherlands; e-mail: [email protected] © 2010 American College of Chest Physicians. Reproduction of this article is prohibited without written permission from the American College of Chest Physicians (http://www.chestpubs.org/ site/misc/reprints.xhtml). DOI: 10.1378/chest.10-0955
References 1. Micames CG, McCrory DC, Pavey DA, Jowell PS, Gress FG. Endoscopic ultrasound-guided fine-needle aspiration for non-small cell lung cancer staging: A systematic review and metaanalysis. Chest. 2007;131(2):539-548. 2. Gu P, Zhao Y Z, Jiang LY, Zhang W, Xin Y, Han BH. Endobronchial ultrasound-guided transbronchial needle aspiration
766
Editorials
Downloaded from chestjournal.chestpubs.org by Kimberly Henricks on October 7, 2010 © 2010 American College of Chest Physicians
3. 4.
5. 6.
7. 8.
9.
10.
11.
12.
for staging of lung cancer: a systematic review and meta-analysis. Eur J Cancer. 2009;45(8):1389-1396. De Leyn P, Lardinois D, Van Schil PE, et al. ESTS guidelines for preoperative lymph node staging for non-small cell lung cancer. Eur J Cardiothorac Surg. 2007;32(1):1-8. Detterbeck FC, Jantz MA, Wallace M, Vansteenkiste J, Silvestri GA; American College of Chest Physicians. Invasive mediastinal staging of lung cancer: ACCP evidence-based clinical practice guidelines (2nd edition). Chest. 2007;132 (3 Suppl): 202S-220S. Annema JT, Versteegh MI, Veseliç M, et al. Endoscopic ultrasound added to mediastinoscopy for preoperative staging of patients with lung cancer. JAMA. 2005;294(8):931-936. Vilmann P, Krasnik M, Larsen SS, Jacobsen GK, Clementsen P. Transesophageal endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA) and endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) biopsy: a combined approach in the evaluation of mediastinal lesions. Endoscopy. 2005;37(9):833-839. Wallace MB, Pascual JM, Raimondo M, et al. Minimally invasive endoscopic staging of suspected lung cancer. JAMA. 2008;299(5):540-546. Hwangbo B, Lee G-K, Lee HS, et al. Transbronchial and transesophageal fine-needle aspiration using an ultrasound bronchoscope in mediastinal staging of potentially operable lung cancer. Chest. 2010;138(4):795-802. Herth FJF, Krasnik M, Kahn N, Eberhardt R, Ernst A. Combined endoscopic-endobronchial ultrasound-guided, fine-needle aspiration of mediastinal lymph nodes through a single bronchoscope in 150 patients with suspected lung cancer. Chest. 2010;138(4):790-794. Rintoul RC, Skwarski KM, Murchison JT, Hill A, Walker WS, Penman ID. Endoscopic and endobronchial ultrasound realtime fine-needle aspiration for staging of the mediastinum in lung cancer. Chest. 2004;126(6):2020-2022. Tournoy KG , Annema JT, Krasnik M, Herth FJ, van Meerbeeck JP. Endoscopic and endobronchial ultrasonography according to the proposed lymph node map definition in the seventh edition of the tumor, node, metastasis classification for lung cancer. J Thorac Oncol. 2009;4(12): 1576-1584. Annema JT, Bohoslavsky R, Burgers S, et al. Implementation of endoscopic ultrasound for lung cancer staging. Gastrointest Endosc. 2010;71(1):64-70.
Viral Community-Acquired Pneumonia If We Do Not Diagnose It and Do Not Treat It, Can It Still Hurt Us? are a generally neglected cause of communityViruses acquired pneumonia (CAP) for a number of
understandable reasons. They are included in investigational and epidemiologic studies, but are not routinely sought in clinical practice because they are difficult to diagnose, primarily because the methods used for this purpose (culture, immunofluorescence for viral antigens, and serology) are expensive and often unavailable, and the results do not become known in a timely manner. In addition, there are few www.chestpubs.org
available antiviral agents, and when these are used therapeutically, they are not as rapidly and clinically effective as we have come to expect from antibacterial therapies. However, viral epidemics do attract our attention, as became clear with Hantavirus in New Mexico in 1993, Severe Acute Respiratory Syndrome (SARS)associated coronavirus in Asia in 2003, and novel 2009 influenza A(H1N1) [A(H1N1)] worldwide in 2009. In the latter instance, we appreciated the important clinical role of this pathogen, which could lead to nonpneumonic lower respiratory tract infection (tracheobronchitis), viral pneumonia (often with acute lung injury), secondary bacterial pneumonia, and probably asymptomatic colonization and carriage.1 The severity of the infection with the novel A(H1N1) in patients of all ages, and not just the elderly as in seasonal influenza, made us pay attention, and we all became familiar with nucleic acid amplification testing (NAAT) methods for definitive diagnosis as we sought new strategies for therapy. Compelling reasons for establishing a definitive diagnosis of epidemic viral infection, even in the absence of optimal therapy, were to identify infected patients so that they could be effectively isolated and also to identify noninfected patients so that they could be removed from isolation when they had a clinical presentation of a lower respiratory tract infection. Viruses are recognized as a common cause of CAP, yet little attention is paid to these organisms in clinical practice because of the diagnostic and therapeutic limitations discussed above. Although influenza remains the predominant viral cause of CAP in adults, the American Thoracic SocietyⲐInfectious Diseases Society of America guidelines for CAP includes other commonly recognized viruses such as respiratory syncytial virus (RSV), adenovirus, and parainfluenza virus, as well as less common viruses, including human metapneumovirus, herpes simplex virus, varicella-zoster virus, SARS-associated coronavirus, and measles virus.2 In studies of CAP from Spain and Chile, using immunofluorescent antigen detection methods, the incidence of CAP caused by viral infection in immune-competent individuals has varied from 18% to 32%, and in the Chilean study, viral pneumonia was particularly common in elderly patients.3,4 Interestingly, in the Chilean study, pure viral infection was present in 23% of patients with CAP, and was more commonly found in patients receiving outpatient antimicrobials, implying that many of these patients may have had bacterial coinfection, but that the bacterial component was eliminated by the use of antibiotics before hospitalization.3 The incidence of viral CAP can be as high as 56% when outpatients are included and when NAAT testing is used.5 CHEST / 138 / 4 / OCTOBER, 2010
Downloaded from chestjournal.chestpubs.org by Kimberly Henricks on October 7, 2010 © 2010 American College of Chest Physicians
767