Novel Robotic Bronchoscopy Approach in Peripheral Pulmonary Nodule Diagnosis

Compared with existing technologies, robotic bronchoscopy results in significantly increased abilities to localize, puncture, and diagnose peripheral pulmonary nodules (PPNs), according to research published in CHEST.

Using a cadaver model, researchers conducted a prospective, single-blinded, randomized, controlled, comparative trial comparing robotic bronchoscopy, electromagnetic navigational bronchoscopy, and radial endobronchial ultrasound with an ultrathin bronchoscope in the evaluation of pulmonary nodules <2 cm in size. Currently, limited data exist regarding the efficacy of robotic bronchoscopy and according to study authors, no comparative data exist comparing the 3 methods.

A total of 60 procedures, targeting 20 PPN pseudotumors, were performed during the study period. Pseudotumors were implanted and distributed across all lobes; the mean nodule size was 16.5±1.5 mm with 80% located in the outer third of the lung and 50% with a computed tomography bronchus sign.

In total, 20 procedures were completed successfully using each of the 3 bronchoscopic modalities. Ten procedures were randomly assigned to electromagnetic navigational bronchoscopy following robotic bronchoscopy; 10 were randomly assigned to robotic bronchoscopy followed by electromagnetic navigational bronchoscopy.

For each PPN, nodule localization resulting in ≥1 attempted needle pass was achieved in 65%, 85%, and 100% of radial endobronchial ultrasound with an ultrathin bronchoscope, electromagnetic navigational bronchoscopy, and robotic bronchoscopy cases, respectively. Robotic bronchoscopy utilization resulted in a “significantly higher rate” of successful localization and needle puncture compared with electromagnetic navigational bronchoscopy (80% vs 45%; P =.022). Radial endobronchial ultrasound with an ultrathin bronchoscope resulted in considerably lower rates of successful localization compared with robotic bronchoscopy (25% vs 80%; P <.001). No significant difference was noted between radial endobronchial ultrasound with an ultrathin bronchoscope and electromagnetic navigational bronchoscopy.

Secondary analyses focused on a broader definition of procedural success; particularly, successful localization and puncture included “all procedures that achieved an assessed needle position of center, peripheral, distal, or adjacent,” according to the investigators. This adjusted definition resulted in higher rates of successful localization and needle puncture across all groups. Success rates were 25% higher for robotic bronchoscopy compared with electromagnetic navigational bronchoscopy, but this result did not reach statistical significance (90% vs 65%; P =.058).

Finally, the researchers analyzed the difference in median distance between needle and target on a “miss” result and identified 6 measurements from 2 targets for robotic bronchoscopy, 11 measurements from 4 targets for electromagnetic navigational bronchoscopy, and 16 measurements from 6 targets for radial endobronchial ultrasound with an ultrathin bronchoscope. The median distance between the needle and target nodule was 0.4 cm in the robotic bronchoscopy, 0.7 cm in the electromagnetic navigational bronchoscopy, and 1.3 cm in the ultrathin bronchoscope groups, respectively. Limitations to the study included the use of a cadaveric model, which may not be generalizable to in vivo interventions, and the lack of concurrent radial endobronchial ultrasound use that “may have resulted in lower yields.”

“While these results are compelling, further study with prospective multicenter comparative trials are needed to better understand the true diagnostic utility of this novel platform and delineate what obstacles [robotic bronchoscopy] may be able to overcome to improve PPN diagnostic yields,” the researchers concluded. “Future studies evaluating new technology should consider incorporating combined modality approaches.”

Disclosure: Several study authors declared affiliations with the pharmaceutical industry. Please see the original reference for a full list of authors’ disclosures.

Reference

Yarmus L, Akulian J, Wahidi M, et al; on behalf of the Interventional Pulmonary Outcomes Group (IPOG). A prospective randomized comparative study of three guided bronchoscopic approaches for investigating pulmonary nodules: the PRECISION-1 Study [published online November 1, 2019]. CHEST. doi:10.1016/j.chest.2019.10.016