Determinants of radiation exposure during mobile cone‐beam CT‐guided robotic‐assisted bronchoscopy

Abstract Background and Objective Robotic‐assisted bronchoscopy (RAB) is an emerging modality to sample pulmonary lesions. Cone‐beam computed tomography (CBCT) can be incorporated into RAB. We investigated the magnitude and predictors of patient and staff radiation exposure during mobile CBCT‐guided shape‐sensing RAB. Methods Patient radiation dose was estimated by cumulative dose area product (cDAP) and cumulative reference air kerma (cRAK). Staff equivalent dose was calculated based on isokerma maps and a phantom simulation. Patient, lesion and procedure‐related factors associated with higher radiation doses were identified by logistic regression models. Results A total of 198 RAB cases were included in the analysis. The median patient cDAP and cRAK were 10.86 Gy cm 2 (IQR: 4.62–20.84) and 76.20 mGy (IQR: 38.96–148.38), respectively. Among staff members, the bronchoscopist was exposed to the highest median equivalent dose of 1.48 μSv (IQR: 0.85–2.69). Both patient and staff radiation doses increased with the number of CBCT spins and targeted lesions ( p < 0.001 for all comparisons). Patient obesity, negative bronchus sign, lesion size <2.0 cm and inadequate sampling by on‐site evaluation were associated with a higher patient dose, while patient obesity and inadequate sampling by on‐site evaluation were associated with a higher bronchoscopist equivalent dose. Conclusion The magnitude of patient and staff radiation exposure during CBCT‐RAB is aligned with safety thresholds recommended by regulatory authorities. Factors associated with a higher radiation exposure during CBCT‐RAB can be identified pre‐operatively and solicit procedural optimization by reinforcing radiation protective measures. Future studies are needed to confirm these findings across multiple institutions and practices. image