A Prospective Study of Safety and the Incremental Diagnostic Value of Transbronchial Cryobiopsy Incorporated into Robotic-Assisted Bronchoscopy in a Cancer Population.

BACKGROUND

Shape-sensing robotic-assisted bronchoscopy (ssRAB) combined with intraoperative imaging optimizes tool-lesion relationship during the sampling of focal pulmonary lesions. Nevertheless, confirmation of tool-in-lesion status is not equivalent to diagnostic sampling. This gap may be bridged by the addition of transbronchial cryobiopsy (TBCB) to traditional transbronchial needle aspiration (TBNA) and forceps biopsy (TBFB); however, the performance of TBCB, specifically with the 1.7-mm cryoprobe, has raised significant safety concerns.

OBJECTIVE

Evaluate the safety of TBCB using the 1.7-mm cryoprobe, added into ssRAB-guided TBNA and TBFB, and performed via a protocolized approach in a cancer center patient population undergoing lung biopsy for focal parenchymal pulmonary lesions. Secondary endpoints included diagnostic yield, accuracy, and TBFB vs. TBCB tissue quality measures.

METHODS

This prospective, single center, single arm study, enrolled patients referred for sampling of focal pulmonary parenchymal lesions. All procedures were performed with image-guided ssRAB with prophylactic balloon occlusion. The primary endpoint was a safety composite of grade ≥ 2 bleeding, grade ≥ 2 pneumothorax, or other biopsy-related grade ≥ 3 complication. Secondary endpoints included conservative diagnostic yield, diagnostic accuracy for malignancy, and biopsy specimen quality measures.

RESULTS

Fifty-one participants were enrolled and underwent image-guided ssRAB. The primary severe adverse event rate was 0% (95% CI 0.0-7.9). The conservative diagnostic yield was 92% and the diagnostic accuracy for malignancy was 90%. TBCB was superior to forceps biopsy in measures of total specimen dimensions, diagnostic tissue area, and degree of crush artifact (P < 0.001 for all comparisons).

CONCLUSION

In cancer patients with localized parenchymal lung lesions, the incorporation of a rigorous safety protocol into image-guided ssRAB allows for the safe acquisition of high-quality peripheral lung TBCB specimen, utilizing the 1.7-mm cryoprobe.

CLINICAL TRIAL REGISTRATION: Clinicaltrials.gov identifier: NCT04548830.