Open AccessThe effectiveness of 4 DCT in children and adults: A pooled analysis
Author(s) -
Huijskens Sophie C.,
Dijk Irma W. E. M.,
Visser Jorrit,
Balgobind Brian V.,
Rasch Coen R. N.,
Alderliesten Tanja,
Bel Arjan
Publication year - 2019
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/acm2.12488
Subject(s) - medicine , diaphragm (acoustics) , nuclear medicine , cone beam computed tomography , breathing , respiratory system , radiology , computed tomography , anatomy , physics , acoustics , loudspeaker
Background While four‐dimensional computed tomography (4 DCT ) is extensively used in adults, reluctance remains to use 4 DCT in children. Day‐to‐day (interfractional) variability and irregular respiration (intrafractional variability) have shown to be limiting factors of 4 DCT effectiveness in adults. In order to evaluate 4 DCT applicability in children, the purpose of this study is to quantify inter‐ and intrafractional variability of respiratory motion in children and adults. The pooled analysis enables a solid comparison to reveal if 4 DCT application for planning purposes in children could be valid. Methods/materials We retrospectively included 90 patients (45 children and 45 adults), for whom the diaphragm was visible on abdominal/thoracic free‐breathing cone beam CT s (480 pediatric, 524 adult CBCT s). For each CBCT , the cranial–caudal position of end‐exhale and end‐inhale positions of the right diaphragm dome were manually selected in the projection images. The difference in position between both phases defines the amplitude. Cycle time equaled inspiratory plus expiratory time. We analyzed the variability of the inter‐ and intrafractional respiratory‐induced diaphragm motion. Results Ranges of respiratory motion characteristics were large in both children and adults (amplitude: 4–17 vs 5–24 mm, cycle time 2.1–3.9 vs 2.7–6.5 s). The mean amplitude was slightly smaller in children than in adults (10.7 vs 12.3 mm; P = 0.06). Interfractional amplitude variability was statistically significantly smaller in children than in adults (1.4 vs 2.2 mm; P = 0.00). Mean cycle time was statistically significantly shorter in children (2.9 vs 3.6 s; P = 0.00). Additionally, intrafractional cycle time variability was statistically significantly smaller in children (0.5 vs 0.7 s; P = 0.00). Conclusions Overall variability is smaller in children than in adults, indicating that respiratory motion is more regular in children than in adults. This implies that a single pretreatment 4 DCT could be a good representation of daily respiratory motion in children and will be at least equally beneficial for planning purposes as it is in adults.