ES 07.04 Endoscopic Options for Solitary Pulmonary Nodules

Abstract

World-wide, aside from men in France, Spain and the Netherlands, peripherally located adenocarcinomas have now overtaken squamous cell carcinoma as the predominant lung cancer cell type. With the implementation of lung cancer screening programs using low dose CT and increasing use of CT imaging for clinical investigations, a large number of people are found to have lung nodules. In contrast to symptomatic lung cancer, the size of screening CT detected or incidental lung nodules suspicious of malignancy is much smaller. Over 75% of screening CT detected lung cancers are ≤20 mm with 20% to 47% of the lung cancers found in the first screening CT and 33% to 62% of lung cancers found in annual repeat screening CT are ≤10 mm.1-4 Because of the small size of these lesions, currently only 20% to 34% of screening CT detected lung cancers are diagnosed by endoscopy. The diagnostic yield of bronchoscopic biopsies is modest.1,2 In the real world setting, even with advanced bronchoscopic methods such as navigation bronchoscopy and radial ultrasound, the diagnostic yield of peripheral lung lesions is less than 60%.5,6 Several factors account for the suboptimal diagnostic yield. The diameter of the airways leading to the lesion may be smaller than the 1.4 mm diameter radial EBUS probe. The lesion may be eccentric rather than perpendicular to the biopsy forceps. Removable of the imaging probe from a guide sheath and re-insertion of biopsy forceps or needle may cause displacement or migration of the guide sheath to a different airway. To improve the diagnostic accuracy, other methods are being developed for endoscopic detection and biopsy of peripheral lung lesions ≤20 mm. Bronchoscopic transparenchymal approach to access peripheral lung nodules from more central airways and real time fluoroscopic transbronchial guidance systems are under evaluation.7,8 Flexible 21G peripheral needles are becoming commercially available for transbronchial aspiration or core biopsy. Small optical imaging probes < 0.5 mm that can be inserted within a 21G needle to confirm abnormal pathology in real time using optical frequency domain imaging9,10 or diffuse reflectance spectroscopy before taking a biopsy. These newer endoscopic approaches hold promise to improve diagnostic accuracy while maintaining the advantage of lower complication rates such as pneumothorax and bleeding compares to CT guided transthoracic lung biopsy. 1. National Lung Screening Research Team, Church TR, Black WC, et al. Results of initial low-dose computed tomographic screening for lung cancer. N Engl J Med. 2013 May 23;368(21):1980-91. 2. Aberle DR, DeMello S, Berg CD, et al. Results of the two incidence screenings in the National Lung Screening Trial. N Engl J Med 2013; 369(10):920-31. 3. McWilliams A, Tammemagi MC, Mayo et al. Probability of cancer in pulmonary nodules detected on first screening CT. N Engl J Med 2013;369:910-9.4. Horeweg N, van Rosmalen J, Heuvelmans MA, et al. Lung cancer probability in patients with CT- detected pulmonary nodules: a prespecified analysis of data from the NELSON trial of low-dose CT screening. Lancet Oncol. 2014 Nov;15(12):1332-41. 5. Ost DE, Ernst A, Lei X, et al. AQuIRE Bronchoscopy Registry. Diagnostic yield and complications of bronchoscopy for peripheral lung lesions. Results of the AQuIRE Registry. Am J Respir Crit Care Med. 2016 Jan 1;193(1):68-77. 6. Ali MS, Trick W, Mba BI, et al. Radial endobronchial ultrasound for the diagnosis of peripheral pulmonary lesions: A systematic review and meta-analysis. Respirology. 2017; 22(3):443-453. 7. Herth FJ, Li S, Jiayuan Sun J, Nader D. Bronchoscopic TransParenchymal Nodule Access: Evaluation of safety and feasibility of Archimedes System. Am J Respir Crit Care Med 2017;195:A7597. 8. Stoy SP, Whitten PE, Al-Zubaidi A, Hogarth K. Bronchoscopic peripheral lung nodule navigation by a novel Live fluoroscopic overlay guidance technology. Am J Respir Crit Care Med 2017;195:A2865. 9. Tan KM, Shishkov M, Chee A, et al. Flexible transbronchial optical frequency domain imaging smart needle for biopsy guidance. Biomed Opt Express 2012; 3::1947-1954. 10. Pahlevaninezhad H, Lee AM, A. R, et al. Endoscopic Doppler optical coherence tomography and autofluorescence imaging of peripheral pulmonary nodules and vasculature. Biomedical Optics xpress. 2015; 6(10):4191-9. Endoscopic biopsy