FIRST-IN-HUMAN VALIDATION OF X-RAY VELOCIMETRY DEMONSTRATES SUPERIOR SENSITIVITY OVER SPIROMETRY AND CT FOR QUANTIFICATION OF REGIONAL LUNG FUNCTION

Abstract

SESSION TITLE: Imaging Posters SESSION TYPE: Original Investigation Posters PRESENTED ON: October 18-21, 2020 PURPOSE: X-ray Velocimetry (XV) is a powerful 4D imaging-based method for quantifying regional ventilation, aiding in the assessment of lung function. Developed through extensive preclinical research, XV has recently been validated in a first-in-human study. Here, we report on the comparison of XV to spirometry and computed tomography (CT) through global correlations and case studies. METHODS: XV Technology was assessed in a clinical trial to monitor changes in lung function in patients receiving radiotherapy for various thoracic cancers (NCT02735746). Patient data were obtained at screening, treatment initiation, and 4 and 12-months post-treatment. Repeatability tests confirmed reproducibility of the analysis. XV metrics such as ventilation defect percent (VDP) and regional ventilation heterogeneity (VH) were compared to pulmonary function tests (PFT) and CT at each time-point. Ventilation histograms and spatial distributions were analyzed at each time-point, enabling monitoring of subtle changes in lung function. RESULTS: Overall, VDP and VH significantly correlated with FEV1 and FEV1/FVC (p<0.05). Additionally, several cases illustrated the advantage of XV over PFT and CT. Here we show two cases where patients had normal PFTs which were stable throughout the study. However, XV analysis showed regional lung function varied over time. In one case, FEV1 and FVC were >100% expected and CT showed mostly clear lungs pre-treatment. However, VDP and VH were well above baseline (15% and 55%, respectively) suggesting functional abnormalities. At 12-months post-treatment, XV metrics had improved (VDP=9% and VH=37%), while PFTs remained stable. Conversely, in another patient, pre-treatment CT could not rule out airway or interstitial disease however VDP and VH were relatively low (10% and 39%, respectively). At 12-months post-treatment, VDP and VH had increased to 13% and 53%, respectively, despite no change in PFTs. Further, regional ventilation maps demonstrated increased specific ventilation in the right lung compared to the left at 12-months, suggesting compensation in the right lung masked dysfunction in PFTs. CONCLUSIONS: XV analysis provided rich lung function information, revealing local variations in ventilation related to dysfunction and compensation that were not identified via PFT or CT. CLINICAL IMPLICATIONS: While XV metrics are consistent overall with gold-standard diagnostics, they offer superior sensitivity, providing considerable value to clinicians and researchers. The enhanced sensitivity associated with XV regional ventilation analysis promises to be invaluable for detecting, monitoring, and treating early stage disease. DISCLOSURES: No relevant relationships by John DeMarco, source=Web Response Employee relationship with 4Dx Please note: $20001 - $100000 Added 05/29/2020 by Chandni Doshi, source=Web Response, value=Salary Employee relationship with 4DMedical Please note: >$100000 Added 05/29/2020 by Jonathan Dusting, source=Web Response, value=Salary Employee relationship with 4DMedical Please note: >$100000 Added 06/01/2020 by Andreas Fouras, source=Web Response, value=Salary Owner/Founder relationship with 4DMedical Please note: >$100000 Added 06/01/2020 by Andreas Fouras, source=Web Response, value=Ownership interest No relevant relationships by Cynthia Martin, source=Web Response No relevant relationships by Stephen Shiao, source=Web Response Employee relationship with 4DMedical Please note: $20001 - $100000 Added 05/27/2020 by Olivia Stephens, source=Web Response, value=Salary 4DMedical Clinical Development relationship with 4DMedical Please note: >$100000 Added 05/29/2020 by Neeraj Vij, source=Web Response, value=CRO service fees Employee relationship with 4DMedical Please note: $20001 - $100000 Added 06/01/2020 by David Wenger, source=Web Response, value=Salary