Using 4DCT-ventilation to characterize lung function changes for pediatric patients getting thoracic radiotherapy

• Type of Material: Article
• Authors: Yevgeniy Vinogradskiy, University of Colorado; Austin Faught, University of Colorado; Richard Castillo, Emory University; Edward Castillo, Beaumont Health System; Thomas Guerrero, Beaumont Health System; Moyed Miften, University of Colorado; Arthur K. Liu, University of Colorado
• Language: English
• Date: 2018-06-26
• Publisher: American Association of Physicists in Medicine
• Publication Version: Final Published Version
• Copyright Statement: © 2018 The Authors. Journal of Applied Clinical Medical Physics published by Wiley Periodicals, Inc. on behalf of American Association of Physicists in Medicine.
• License: Creative Commons Attribution 4.0 International
• Final Published Version (URL): http://dx.doi.org/10.1002/acm2.12397
• Title of Journal or Parent Work: Journal of Applied Clinical Medical Physics
• ISSN: 1526-9914
• Volume: 19
• Issue: 5
• Start Page: 407
• End Page: 412
• Grant/Funding Information: This work was partially funded by NCI/NIH grant R01CA200817 (YV, AF, MM, EC, RC, TG).
• Keywords: dose-response assessment; pediatric radiotherapy; CT ventilation; lung function imaging
• Research Categories: Physics, Radiation; Health Sciences, Oncology

Abstract

Purpose: A form of lung functional imaging has been developed that uses 4DCT data to calculate ventilation (4DCT-ventilation). Because 4DCTs are acquired as standard-of-care to manage breathing motion during radiotherapy, 4DCT-ventilation provides functional information at no extra dosimetric or monetary cost. 4DCT-ventilation has yet to be described in children. 4DCT-ventilation can be used as a tool to help assess post-treatment lung function and predict for future clinical thoracic toxicities for pediatric patients receiving radiotherapy to the chest. The purpose of this work was to perform a preliminary evaluation of 4DCT-ventilation-based lung function changes for pediatric patients receiving radiotherapy to the lungs. Methods: The study used four patients with pre and postradiotherapy 4DCTs. The 4DCTs, deformable image registration, and a density-change-based algorithm were used to compute pre and post-treatment 4DCT-ventilation images. The post-treatment 4DCT-ventilation images were compared to the pretreatment 4DCT-ventilation images for a global lung response and for an intrapatient dose–response (providing an assessment for dose-dependent regional dose–response). Results: For three of the four patients, a global ventilation decline of 7–37% was observed, while one patient did not demonstrate a global functional decline. Dose–response analysis did not reveal an intrapatient dose–response from 0 to 20 Gy for three patients while one patient demonstrated increased 4DCT-ventilation decline as a function of increasing lung doses up to 50 Gy. Conclusions: Compared to adults, pediatric patients have unique lung function, dosimetric, and toxicity profiles. The presented work is the first to evaluate spatial lung function changes in pediatric patients using 4DCT-ventilation and showed lung function changes for three of the four patients. The early changes demonstrated with lung function imaging warrant further longitudinal work to determine whether the imaging-based early changes can be predicted for long-term clinical toxicity.