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Background: In adults, a single pre-treatment four-dimensional CT (4D-CT) acquisition is often used to account for respiratory-induced target motion during radiotherapy. However, studies have indicated that a 4D-CT is not always representative for respiratory motion. Our aim was to investigate whether respiratory-induced diaphragm motion in children on a single pre-treatment 4DCT can accurately predict respiratory-induced diaphragm motion as observed on cone beam CTs (CBCTs).
Methods: Twelve patients (mean age 14.5 yrs.; range 8.6-17.9 yrs) were retrospectively included based on visibility of the diaphragm on abdominal or thoracic imaging data acquired during free breathing. A 4DCT for planning purposes and daily/weekly CBCTs (total 125; range 4-29 per patient) acquired prior to dose delivery were available. The amplitude, corresponding to the difference in position of the diaphragm in cranial-caudal direction in end-inspiration and end-expiration phases, was extracted from the 4DCT (A). The amplitude in CBCTs (A) was defined as displacement between averaged in- and expiration diaphragm positions on corresponding projection images, and the distribution of A was compared to A (one-sample t-test, significance level p < 0.05).
Results: Over all patients, the mean A was 10.4 mm and the mean A 11.6 mm. For 9/12 patients, A differed significantly (p < 0.05) from A. Differences > 3 mm were found in 69/125 CBCTs (55%), with A mostly underestimating A. For 7/12 patients, diaphragm positions differed significantly from the baseline position.
Conclusion: Respiratory-induced diaphragm motion determined on 4DCT does not accurately predict the daily respiratory-induced diaphragm motion observed on CBCTs, as the amplitude and baseline position differed statistically significantly in the majority of patients. Regular monitoring of respiratory motion during the treatment course using CBCTs could yield a higher accuracy when a daily adaptation to the actual breathing amplitude takes place.
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http://dx.doi.org/10.1186/s13014-018-1143-6 | DOI Listing |
J Endovasc Ther
August 2025
Department of Vascular and Endovascular Surgery, Nancy University Hospital, University of Lorraine, Nancy, France.
The endovascular surgical approach provides a minimally invasive treatment of abdominal aortic aneurysms with less perioperative morbidity. This technique depends heavily on imaging to diagnose, plan surgical treatment, conduct the surgical procedure, and follow-up with patients. Image fusion technique was proposed to decrease radiation and injected contrast exposure; however, the accuracy of image fusion still needs to be improved.
View Article and Find Full Text PDFPediatr Radiol
May 2025
University of Toronto, 27 King's College Cir, Toronto, ON, M5S 1A1, Canada.
Background: Conventional four-dimensional (4D) flow magnetic resonance imaging (MRI) is limited by long scan times, particularly in pediatric congenital heart disease (CHD) patients.
Objective: This study evaluates accelerated 4D flow MRI incorporating respiratory compensation and cardiac view sharing in healthy adults and pediatric CHD patients.
Materials And Methods: Subjects underwent 5-min free-breathing protocol with a three-dimensional (3D) radial trajectory and compressed sensing reconstruction.
Cureus
April 2024
Department of Radiation Oncology, Southern Tohoku Proton Therapy Center, Koriyama, JPN.
Background To evaluate the respiratory-induced intrafractional diaphragm motion and interfractional diaphragm displacement in pediatric patients with neuroblastoma (NBL). Materials and methods Ten pediatric patients with a mean age of 4.5 years (range: 1.
View Article and Find Full Text PDFPhys Imaging Radiat Oncol
October 2023
Medical Radiation Physics, Department of Clinical Sciences Lund, Lund University, Lund, Sweden.
Background And Purpose: Stereotactic body radiotherapy (SBRT) has emerged as a promising treatment for patients with ventricular tachycardia (VT) who do not respond to standard treatments. However, the management of respiratory motion during treatment remains a challenge. This study aimed to investigate the effect of abdominal compression (AC) on respiratory induced motion in the heart.
View Article and Find Full Text PDFJ Biomed Phys Eng
October 2022
PhD, Department of Radiology Technology, Faculty of Allied Medical Sciences, Shahid Beheshti University of Medical Sciences, Tehran, Iran.
Background: Respiratory movement and the motion range of the diaphragm can affect the quality and quantity of prostate images.
Objective: This study aimed to investigate the magnitude of respiratory-induced errors to determine Dominant Intra- prostatic Lesions (DILs) in positron emission tomography (PET) images.
Material And Methods: In this simulation study, we employed the 4D NURBS-based cardiac-torso (4D-NCAT) phantom with a realistic breathing model to simulate the respiratory cycles of a patient to assess the displacement, volume, maximum standardized uptake value (SUV), mean standardized uptake value (SUV), signal to noise ratio (SNR), and the contrast of DILs in frames within the respiratory cycle.