Robotic Bronchoscopy for Diagnosing Peripheral Lung Lesions

Improved diagnosis of peripheral lung lesions is of increasing importance because the diagnostic yield of current bronchoscopic approaches remains suboptimal. Therefore, we read with great interest the article in CHEST (February 2021) by Chen et al1Chen A.C. Pastis Jr., N.J. Mahajan A.K. et al.Robotic bronchoscopy for peripheral pulmonary lesions: a multicenter pilot and feasibility study (BENEFIT).Chest. 2021; 159: 845-852Abstract Full Text Full Text PDF PubMed Scopus (32) Google Scholar who evaluated robotic bronchoscopy in a prospective pilot study. We congratulate them on the high success rate (96%) of lesion localization by radial endobronchial ultrasound scanning. Can the authors explain how in almost all patients, independent of the presence or absence of a bronchus sign, lesions were detected with radial endobronchial ultrasound scanning? Were patients selected based on chest CT, or were consecutive patients included? What was the rationale to have “navigational success” as the primary end point? In our opinion, the main determinate of a successful diagnostic procedure is whether representative samples are retrieved; therefore, diagnostic yield would qualify best as the primary end point. Although we appreciate the rigorous definition of (non-)diagnostic specimens, the discrepancy between lesion detection (96%) and diagnostic yield (74%) is striking. How do the authors explain this? The findings of Chen et al1Chen A.C. Pastis Jr., N.J. Mahajan A.K. et al.Robotic bronchoscopy for peripheral pulmonary lesions: a multicenter pilot and feasibility study (BENEFIT).Chest. 2021; 159: 845-852Abstract Full Text Full Text PDF PubMed Scopus (32) Google Scholar support those of a previous retrospective experience,2Chaddha U. Kovacs S.P. Manley C. et al.Robot-assisted bronchoscopy for pulmonary lesion diagnosis: results from the initial multicenter experience.BMC Pulm Med. 2019; 19: 243Crossref PubMed Scopus (39) Google Scholar which suggests that robotic bronchoscopy provides enhanced navigational success but lacks tool-in-lesion confirmation. This is in-line with a cadaver study published in CHEST, in which robotic bronchoscopy demonstrated improved navigation ability over other bronchoscopic techniques but a near-miss rate of the target lesion of 20% remained.3Yarmus L. Akulian J. Wahidi M. et al.A prospective randomized comparative study of three guided bronchoscopic approaches for investigating pulmonary nodules: the PRECISION-1 study.Chest. 2020; 157: 694-701Abstract Full Text Full Text PDF PubMed Scopus (27) Google Scholar In our opinion, the aforementioned studies1Chen A.C. Pastis Jr., N.J. Mahajan A.K. et al.Robotic bronchoscopy for peripheral pulmonary lesions: a multicenter pilot and feasibility study (BENEFIT).Chest. 2021; 159: 845-852Abstract Full Text Full Text PDF PubMed Scopus (32) Google Scholar, 2Chaddha U. Kovacs S.P. Manley C. et al.Robot-assisted bronchoscopy for pulmonary lesion diagnosis: results from the initial multicenter experience.BMC Pulm Med. 2019; 19: 243Crossref PubMed Scopus (39) Google Scholar, 3Yarmus L. Akulian J. Wahidi M. et al.A prospective randomized comparative study of three guided bronchoscopic approaches for investigating pulmonary nodules: the PRECISION-1 study.Chest. 2020; 157: 694-701Abstract Full Text Full Text PDF PubMed Scopus (27) Google Scholar underline that for adequate bronchoscopic peripheral lung lesion analysis, a two-step approach is desired. First, a bronchoscopic tool is needed to navigate within close proximity of the target lesion. In this respect, the observed 2.3-cm distance between the bronchoscope tip and target lesion by Chen et al1Chen A.C. Pastis Jr., N.J. Mahajan A.K. et al.Robotic bronchoscopy for peripheral pulmonary lesions: a multicenter pilot and feasibility study (BENEFIT).Chest. 2021; 159: 845-852Abstract Full Text Full Text PDF PubMed Scopus (32) Google Scholar is encouraging. Second, a real-time feedback tool, such as cone-beam CT or confocal laser endomicroscopy (CLE), is desirable to confirm the optimal needle positioning. Do the authors support our hypothesis? In our experience, bronchoscopic CLE imaging through a needle in central and peripheral lung tumors enables realtime malignancy detection at the needle tip4Kramer T, Wijmans L, Bruin de DM, et al. Bronchoscopic needle based confocal laser endomicroscopy as a real-time detection tool for peripheral lung cancer. Thorax. 2021. In press.Google Scholar,5Wijmans L. Yared J. de Bruin D.M. et al.Needle-based confocal laser endomicroscopy for real-time diagnosing and staging of lung cancer.Eur Respir J. 2019; 53: 1801520Crossref PubMed Scopus (11) Google Scholar which allows fine-tuning of the optimal needle positioning. Robotic bronchoscopy combined with real-time tool-in-lesion confirmation with the use of needle based CLE imaging is now prospectively evaluated in an ongoing trial (ClinicalTrials.gov NCT04441749) and could potentially reduce the current substantial near-miss rate. Although the results by Chen et al1Chen A.C. Pastis Jr., N.J. Mahajan A.K. et al.Robotic bronchoscopy for peripheral pulmonary lesions: a multicenter pilot and feasibility study (BENEFIT).Chest. 2021; 159: 845-852Abstract Full Text Full Text PDF PubMed Scopus (32) Google Scholar look promising, the discrepancy between navigational success and diagnostic yield requires additional prospective studies to determine best clinical practice and combination of techniques to improve the diagnosis of peripheral lung lesions. Robotic Bronchoscopy for Peripheral Pulmonary Lesions: A Multicenter Pilot and Feasibility Study (BENEFIT)CHESTVol. 159Issue 2PreviewThis is the first, prospective, multicenter study of robotic bronchoscopy in patients with PPLs. Successful lesion localization was achieved in 96.2% of cases, with an adverse event rate comparable with conventional bronchoscopic procedures. Additional large prospective studies are warranted to evaluate procedure characteristics, such as diagnostic yield. Full-Text PDF Open AccessResponseCHESTVol. 160Issue 3PreviewWe appreciate the interest that Kramer et al have taken regarding our article on robotic bronchoscopy for peripheral pulmonary lesions (BENEFIT).1 We will first address their questions regarding specific content within the article before commenting on their proposal for combining robotic bronchoscopy with additional tools and techniques. Full-Text PDF