Open AccessUsing 4 DCT ‐ventilation to characterize lung function changes for pediatric patients getting thoracic radiotherapy
Author(s) -
Vinogradskiy Yevgeniy,
Faught Austin,
Castillo Richard,
Castillo Edward,
Guerrero Thomas,
Miften Moyed,
Liu Arthur K.
Publication year - 2018
Publication title -
journal of applied clinical medical physics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.83
H-Index - 48
ISSN - 1526-9914
DOI - 10.1002/acm2.12397
Subject(s) - lung function , medicine , radiation therapy , radiology , pulmonary function testing , lung , ventilation (architecture) , lung ventilation , medical physics , nuclear medicine , physics , thermodynamics
Purpose A form of lung functional imaging has been developed that uses 4 DCT data to calculate ventilation (4 DCT ‐ventilation). Because 4 DCT s are acquired as standard‐of‐care to manage breathing motion during radiotherapy, 4 DCT ‐ventilation provides functional information at no extra dosimetric or monetary cost. 4 DCT ‐ventilation has yet to be described in children. 4 DCT ‐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 4 DCT ‐ventilation‐based lung function changes for pediatric patients receiving radiotherapy to the lungs. Methods The study used four patients with pre and postradiotherapy 4 DCT s. The 4 DCT s, deformable image registration, and a density‐change‐based algorithm were used to compute pre and post‐treatment 4 DCT ‐ventilation images. The post‐treatment 4 DCT ‐ventilation images were compared to the pretreatment 4 DCT ‐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 4 DCT ‐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 4 DCT ‐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.