Objective: To analyze the effectiveness and safety of robotic-assisted bronchoscopy (RAB) for subsolid nodules, including semi-solid nodules (SSN) and ground glass nodules (GGN).

Methods: This is a subset analysis of a multicenter, prospective observational study that investigates patients with subsolid nodules undergoing RAB. Effectiveness is defined by reach, measured by radial endobronchial ultrasound (rEBUS) confirmation and median distance from bronchoscope tip to the lesion prior to biopsy, and access, measured by sensitivity for malignancy and diagnostic yield (DY). Adverse events were collected to assess safety.

Results: Of 679 patients analyzed, 91 (13.4%) had subsolid nodules: 78 were SSN and 13 were pure GGN. Median subsolid nodule size was 18.5 mm, 61.5% were in the upper lobes, and 89.0% were in the outer two-thirds of the lung. The malignancy rate was 45.1%, predominantly adenocarcinoma. rEBUS localization rates were 81.4% for SSN and 61.5% for GGN, with median distances from the bronchoscope tip of 22.0 mm and 19.5 mm, respectively. Sensitivity for malignancy was 77.8% for SSN and 75.0% for GGN, while the strict DY was 50.0% for SSN and 61.5% for GGN. Non-diagnostic results occurred in 31 subsolid nodules (34.1%) at the index biopsy. The pneumothorax incidence was 4.4%, and pneumothorax requiring chest tube was 2.2% in the subsolid nodule cohort. There were no bleeding, respiratory complications, or mortalities reported in the subsolid nodule cohort in the 7-day follow-up period.

Conclusions: Our findings confirm that RAB is safe and effective for diagnosing subsolid nodules.