ULTRA-LOW DOSE CONE-BEAM CT INCREASES POSITIVE DIAGNOSIS RATE OF PERIPHERAL NODULE BRONCHOSCOPY WHILE IMPROVING RADIATION SAFETY

TYPE: Late Breaking Abstract TOPIC: Procedures PURPOSE: Cone-beam CT (CBCT) can be used during electromagnetic navigation bronchoscopy (ENB) to improve accuracy and safety of biopsy. Although the added value of CBCT is recognized, there are concerns about radiation exposure. We investigate the impact of a ultra-low-dose CBCT protocol. METHODS: A single institution, retrospective, comparative study of CBCT-ENB for biopsies using two radiation protocols (standard (Gp1) vs ultra-low-dose (Gp2)). We estimated the total E, E attributed to CBCT (E1) and E attributed to fluoroscopy (E2) per lesion from the dose-area-product (conversion factor 0.16 mSv/Gy·cm2). Secondary outcomes were number of CBCT runs and positive diagnosis (PD) rate. RESULTS: From Jan 2015-22, 386 patients (mean age 68.3) underwent CBCT-ENB for biopsy of 452 pulmonary lesions (mean size 19.5 mm): Gp1 121 patients with 138 lesions, Gp2 258 patients with 306 lesions. Total E was 4.85 mSv (Gp1) vs 1.72 mSv (Gp2) (64.5% decrease, p<0.01). E1 was 3.57 mSv (Gp1) vs 1.46 mSv (Gp2) (p<0.01) and E2 was 1.28 mSv (Gp1) vs 0.29 mSv (Gp2) (p<0.01). The number of CBCT runs increased from 3.65 to 5.68 (55.6% increase, p<0.01, dose-per-CBCT-run 0.98 mSv vs 0.26 mSv). PD rate increased from 61.7% to 72.0% (16.7% increase, p=0.05). CONCLUSIONS: The ultra-low dose protocol reduced radiation exposure compared to standard dose protocol. This allowed for more CBCT runs, more accurate tool positioning, and an improved diagnostic rate. CLINICAL IMPLICATIONS: Ultra-low dose CBCT not only reduces radiation exposure, but allows more iterative CBCT runs and improved diagnostic rate and should be adopted more widely. DISCLOSURE: Funded student internship at Philips Image Guided Therapy Systems (Best, The Netherlands) (applies to submitter). Two co-authors are employee's of Philips Image Guided Therapy Systems (Best, The Netherlands). KEYWORD: Interventional pulmonology