Diagnostic performance of monarch robotic bronchoscopy with and without mobile cone-beam CT support

Robotic-assisted bronchoscopy (RAB) is limited by CT-to-body divergence. Cone-beam CT (CBCT) may enhance tool-to-lesion alignment and diagnostic yield (DY), but the benefit of integrating mobile CBCT (mCBCT) into the Monarch^TM RAB remains understudied. This is the first study to evaluate diagnostic performance between Monarch alone versus Monarch plus mCBCT for peripheral pulmonary lesion (PPL) biopsy, hypothesizing improved DY with the combined approach.

This single-center retrospective study examined adults undergoing RAB biopsy for PPLs (May 2019-March 2023), applying a strict DY definition. Clinical characteristics and outcomes were evaluated in Monarch and Monarch plus mCBCT groups.

Of 331 cases, 179 used Monarch and 152 used Monarch plus mCBCT. There was no significant difference in baseline characteristics. DY was not different (70.9 % in Monarch vs 71.7 % in Monarch plus mCBCT, p = 0.976) nor were complication rates (7.3 % in Monarch vs. 3.9 % in Monarch plus mCBCT, p = 0.291). In the Monarch group, the procedure duration was longer (77 min in Monarch vs. 69 min in Monarch plus mCBCT, p = 0.002) and the radiation dose was lower (7.4 mGy in Monarch vs. 285.9 mGy in Monarch plus mCBCT, p < 0.001). Adjusted analysis demonstrated that mCBCT was not associated with improved DY (OR [95 % CI]: 1.33[0.78-2.28]) or reduced risk for complications (OR [95 % CI]: 0.41 [0.13; 1.14]). DY increased with larger nodule size but not with lesion location.

Evaluating outcomes across two sequential practice eras, the addition of mCBCT to Monarch RAB did not significantly improve DY or reduce complications but reduced procedure duration at the cost of increased radiation exposure.

- Evaluated diagnostic performance of Monarch™ vs. Monarch™ + mobile Cone-beam CT (mCBCT). - Diagnostic yield and complication rates were similar. - The mCBCT group had shorter procedure times and about 40-fold higher radiation doses.

The study findings have been presented in American Association for Bronchology and Interventional Pulmonology Annual Conference in 2024. The institutional review board approved all protocols (IRB 23-005284).