Robotic-assisted bronchoscopy safe in targeting small, peripheral lesions

Key takeaways:

• The study included 679 patients with robotic-assisted bronchoscopy.
• Median lesion size was 18.5 mm with a median distance from pleural surface of 5 mm.
• At 12 months, 65.7% of patients had cancer.

BOSTON — Robotic-assisted bronchoscopy safely targeted small and peripheral lesions with robust diagnostic yield across a range of definitions and methodologies, according to a presentation at the CHEST Annual Meeting.

These findings also indicated the technology’s applicability among diverse patient populations and academic and community centers, Septimiu D. Murgu, MD, interventional pulmonologist with University of Chicago Medicine, and colleagues wrote.

Conducted across 21 sites in the United States and Hong Kong, the study included 679 patients (mean age, 68.7 years; 55.4% female; 86.5% white) with lung lesions of 8 mm to 50 mm who had a robotic-assisted bronchoscopy (RAB) via the MONARCH (Auris Health) platform. The researchers called it the largest prospective study of RAB to date.

The cohort included 77.5% current or previous tobacco users, 42.2% with underlying obstructive lung disease and 13.1% with prior lung cancer. The researchers followed the patients for 12 months.

Lesion sizes had a median of 18.5 mm (interquartile range [IQR], 13.5-26.5) with a median distance from the pleural surface of 5 mm (IQR, 0-16). Also, 86.6% (n = 587) of the lesions were solid, 87.5% (n = 593) were in the lung’s outer surface and 59.9% (n = 406) had bronchus sign.

The primary endpoint compiled adverse events related to the device or procedure including pneumothorax or bleeding requiring intervention and respiratory failure according to independent assessors using the Common Terminology Criteria for Adverse Events (CTCAE).

Specifically, pneumothorax and bleeding with a CTCAE grade of 2 or higher and respiratory failure with a CTCAE grade of 4 or higher were considered adverse events.

The researchers also investigated navigation success, procedure time, radial probe endobronchial ultrasound (R-EBUS) confirmation and diagnostic yield as secondary endpoints.

The study steering committee independently reviewed and adjudicated all pathology reports from the index procedure and categorized them a priori as malignant, specific benign, non-specific benign or non-diagnostic. The researchers additionally said they used strict, intermediate and liberal methodologies to calculate diagnostic yield.

The intermediate methodology used subsequent pathology results from the following 12 months to determine definitive diagnoses for the lesions deemed non-specific benign at index.

The liberal methodology used subsequent measurements of lesion size through 12 months to determine definitive diagnoses for the lesions classified as non-diagnostic at index.

Overall, 3.8% of patients (n = 26) met the composite primary endpoint, including 19 with pneumothorax and seven with bleeding. There were no cases of respiratory failure.

R-EBUS confirmed lesion localization in 93.6% of the solid nodules and in 78.3% of the subsolid nodules. Also, 2.1% of the patients (n = 14) had a salvage procedure, and 65.7% had cancer through 12 months.

Diagnostic yields included 63.8% with a strict, index only approach, 76.6% with an intermediate approach and 87% with a liberal approach.

Based on these findings, the researchers concluded that physicians were able to safely use RAB to target small and peripheral lesions, with robust diagnostic yield, in a broad span of definitions and methodologies indicating its applicability for varied patient populations treated by academic and community centers alike.