Effective Radiation Dose from Cone-Beam Computed Tomography Guidance during Bronchoscopic Tumour Ablation

Introduction: Endobronchial radiofrequency ablation (RFA) is a novel minimally invasive approach to management of peripheral non-small-cell lung cancer (NSCLC) in medically inoperable patients. Minimally invasive ablative techniques are generally delivered with cone-beam computed tomography (CBCT) guidance. CBCT requires a significant number of two dimensional imaging projections to be acquired which is then reconstructed as a three-dimensional cone-beam image. The objective of this study was to determine the radiation dosimetry consequent to use of CBCT guidance for bronchoscopic RFA. Methods: Post hoc analysis of data following bronchoscopic RFA of stage I biopsy-confirmed NSCLC performed with CBCT. Effective dose estimates for these patients were calculated using PCXMC2.0 software. Results: Ten patients underwent bronchoscopic RFA, with a median 3 (range 2-4) CBCT spins per procedure. Mean dose area product (DAP) per procedure was 7,778 mu Gy.m2 (+/- 4,743) with an effective dose of 11.6 mSv (+/- 7.4). The DAP per spin for these 10 patients varied from 83.8 to 8,625.6 mu Gy.m2 (effective dose range 0.15-13.81 mSv). Conclusion: This is the first study to report radiation dosimetry consequent to CT guidance for bronchoscopic RFA procedures. Effective doses appear comparable to other CT fluoroscopic procedures.