Rebuttal From Drs Folch and Majid

Abstract

Our colleagues, Drs Kinsey and Channick,1Kinsey CM Channick CL Counterpoint: are >50 supervised procedures required to develop competency in performing endobronchial ultrasound-guided tranbronchial needle aspiration for lung cancer staging? No.Chest. 2013; 143: 891-893Abstract Full Text Full Text PDF PubMed Scopus (16) Google Scholar bring up excellent points. We agree that convex-probe endobronchial ultrasound-guided transbronchial needle aspiration (CP-EBUS) has impacted the diagnosis and evaluation of patients with lung cancer, leading to increased popularity in mainstream clinical practice. However, we disagree on the number that they consider appropriate for acquiring the necessary skills to perform a complete and systematic lymph node sampling for staging of lung cancer.2Detterbeck F Puchalski J Rubinowitz A Cheng D Classification of the thoroughness of mediastinal staging of lung cancer.Chest. 2010; 137: 436-442Abstract Full Text Full Text PDF PubMed Scopus (84) Google Scholar They quote a study by Adawi and Simoff3Adawi RS Simoff MJ Endobronchial ultrasound guided transbronchial needle aspiration: a preliminary experience.Journal of Bronchology. 2008; 15: 87-90Crossref Scopus (4) Google Scholar; interestingly, the study is from a high-volume center where they successfully sampled the target in 78% of the cases (39 of 50). Is 78% yield good enough? These numbers are comparable to those reported by Fernández-Villar and colleagues4Fernández-Villar A Leiro-Fernández V Botana-Rial M Represas-Represas C Núñez-Delgado M The endobronchial ultrasound-guided transbronchial needle biopsy learning curve for mediastinal and hilar lymph node diagnosis.Chest. 2012; 141: 278-279Abstract Full Text Full Text PDF PubMed Scopus (44) Google Scholar and Medford,5Medford AR Learning curve for endobronchial ultrasound-guided transbronchial needle aspiration.Chest. 2012; 141: 1643Abstract Full Text Full Text PDF PubMed Scopus (39) Google Scholar who reported 82% and 85% accuracy in the octile of 21 to 40 cases. However, their studies also show that accuracy >90% is reached between 80 and 100 cases. The pulmonary and thoracic surgery literature has embraced the studies that show CP-EBUS and mediastinoscopy to have comparable sensitivity, specificity, and accuracy. We should not forget that those studies were done by experienced interventional pulmonologists and thoracic surgeons. Furthermore, the continued exposure to enough cases is another matter of concern. The steepness of the learning curve is also related to exposure over time. That is, if a clinician is exposed to a significant number of cases in a short period of time, his or her technical skill is likely to improve faster than if he or she were exposed over a long period of time.6Kemp SV El Batrawy SH Harrison RN et al.Learning curves for endobronchial ultrasound using cusum analysis.Thorax. 2010; 65: 534-538Crossref PubMed Scopus (125) Google Scholar This argues in favor of concentrating the cases in large-volume centers. Regarding safety, it is clear that the procedure itself is safe, but the consequences of over- or understaging cannot be overemphasized. As estimates on the experience necessary to acquire competence are not firm, it is proper that if one must err, one should err on the side of more extensive training to reduce misclassification. It is undeniable that the skill required to reach a subcarinal lymph node is significantly different from the skill required to identify and perform biopsy on lymph nodes in stations 2R, 2L, 4L, 10, and 11. Contrary to our colleagues, we believe that the cognitive aspects of staging of lung cancer are different from reaching for “the low-hanging fruit” of an enlarged lymph node. Furthermore, the knowledge of the different lymph node maps and their implications in establishing the clinical stage does matter to the individual patient. Our colleagues also suggest that it is unnecessary and impractical to have more stringent competency requirements for endobronchial ultrasound-guided transbronchial needle aspiration performed for lung cancer staging. We would agree, if the consequences of inaccurate staging were not severe and life changing. However, precision, accuracy, and efficiency are paramount during the procedure to maximize safety and provide adequate treatment and prognosis. We agree that the opportunities to train in advanced CP-EBUS are limited. However, if we lower the standards in an attempt to increase the number of available practitioners, we should also consider shortening the length of medical school, residency, or fellowship training to meet the current health-care demands. Instead, the overall trend is toward longer and more exhaustive medical training with further specialization. As an example, we now have a board of interventional cardiology for congenital heart disease in adults. We believe that higher standards foster better care. But following our colleagues premise, we also conclude that lower standards foster more care. Finally, whether the number is 50 or more for CP-EBUS is debatable, but at least we have brought the issue up for discussion. This is a discussion that should happen at every academic center and community hospital considering CP-EBUS for lung cancer staging.