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CBCT Radiation

Kihong Son, Jin Sung Kim, Hoyeon Lee, Seungryong Cho
This study investigates dose distribution due to kV cone-beam computed tomography (CBCT) for the patients undergoing CBCT-based image-guided radiation therapy (IGRT). The kV-CBCT provides an efficient image-guidance tool for acquiring the latest volumetric image of a patient's anatomy, and has been being routinely used in clinics for an accurate treatment setup. Imaging radiation doses resulting from six different acquisition protocols of the on-board imager (OBI) were calculated using a Geant4 Application for Tomographic Emission (GATE) Monte Carlo simulation toolkit, and the absorbed doses by various organs were analyzed for the adult and pediatric numerical XCAT phantoms in this study...
October 20, 2016: Radiation Protection Dosimetry
Johann Malina-Altzinger, Georg Damerau, Klaus W Grätz, P D Bernd Stadlinger
BACKGROUND: The aim of this study was to evaluate the validity and the inter- and intra-examiner reliability of panoramic-radiograph-driven findings of different maxillary sinus anatomic variations and pathologies, which had initially been prediagnosed by cone beam computed tomography (CBCT). METHODS: After pairs of two-dimensional (2D) panoramic and three-dimensional (3D) CBCT images of patients having received treatment at the outpatient department had been screened, the predefinition of 54 selected maxillary sinus conditions was initially performed on CBCT images by two blinded consultants individually using a questionnaire that defined ten different clinically relevant findings...
December 2015: Int J Implant Dent
Navnina Bhatia, David Tisseur, Solene Valton, Jean Michel Létang
Due to the increased cone beam coverage and the introduction of flat panel detector, the size of X-ray illumination fields has grown dramatically in Cone Beam Computed Tomography (CBCT), causing an increase in scatter radiation. Existing reconstruction algorithms do not model the scatter radiation, so scatter artifacts appear in the reconstruction images. The contribution of scattering of photons inside the detector itself becomes prominent and challenging in case of X-ray source of high energy (over a few 100 keV) which is used in typical industrial Non Destructive Testing (NDT)...
October 6, 2016: Journal of X-ray Science and Technology
Ying Hou, Stephanie Lee, Vishesh Agrawal, John Romano, Elizabeth H Baldini, Aileen B Chen, David E Kozono, Joseph H Killoran, Matthew Wagar, Fred L Hacker, Hugo Jwl Aerts, John H Lewis, Raymond H Mak
INTRODUCTION: Quantification of volume changes on cone beam computed tomography (CBCT) during lung stereotactic body radiation therapy (SBRT) for non-small cell lung cancer (NSCLC) may provide a useful radiological marker for radiation response and for adaptive treatment planning. This study quantifies inter-scan and inter-observer variability in tumour volume delineation on CBCT. METHODS: Three clinicians independently contoured the primary gross tumour volume (GTV) manually on CBCTs taken immediately before SBRT treatment (pre) and after the same SBRT treatment (post) for 19 NSCLC patients...
October 5, 2016: Journal of Medical Imaging and Radiation Oncology
Anna Maria Ierardi, Filippo Piacentino, Francesca Giorlando, Alberto Magenta Biasina, Alessandro Bacuzzi, Raffaele Novario, Gianpaolo Carrafiello
OBJECTIVE: To demonstrate the feasibility of percutaneous nucleoplasty procedures at L5/S1 level using cone beam CT (CBCT) and its associated image guidance technology for the treatment of lumbar disc herniation (LDH). MATERIALS AND METHODS: We retrospectively reviewed 25 cases (20 men, 5 women) of LDH at L5/S1 levels. CBCT as guidance imaging was chosen after a first unsuccessful fluoroscopy attempt that was related to complex anatomy (n = 15), rapid pathological changes due to degenerative diseases (n = 7) or both (n = 3)...
October 3, 2016: Skeletal Radiology
Qi Shi, Nanbo Sun, Tao Sun, Jing Wang, Shan Tan
The exposure of normal tissues to high radiation during cone-beam CT (CBCT) imaging increases the risk of cancer and genetic defects. Statistical iterative algorithms with the total variation (TV) penalty have been widely used for low dose CBCT reconstruction, with state-of-the-art performance in suppressing noise and preserving edges. However, TV is a first-order penalty and sometimes leads to the so-called staircase effect, particularly over regions with smooth intensity transition in the reconstruction images...
September 1, 2016: Biomedical Optics Express
Noor Mail, Muhammad Yusuf, Nazeeh Alothmany, A Abdulrahman Kinsara, Fahad Abdulkhaliq, Suliman M Ghamdi, Abdelhamid Saoudi
Cone-beam computed tomography CBCT systems are used in radiation therapy for patient alignment and positioning. The CBCT imaging procedure for patient setup adds substantial radiation dose to patient's normal tissue. This study pre-sents a complete procedure for the CBCT dosimetry using the InLight optically-stimulated-luminescence (OSL) nanoDots. We report five dose parameters: the mean slice dose (DMSD); the cone beam dose index (CBDIW); the mean volume dose (DMVD); point-dose profile, D(FOV); and the off-field Dose...
2016: Journal of Applied Clinical Medical Physics
Lotte E J R Schyns, Isabel P Almeida, Stefan J van Hoof, Benedicte Descamps, Christian Vanhove, Guillaume Landry, Patrick V Granton, Frank Verhaegen
OBJECTIVES: The aim of this work was to investigate if quantitative dual energy CT (DECT) imaging is feasible for small animal irradiators with an integrated cone beam CT (CBCT) system. METHODS: The optimal imaging protocols were determined by analyzing different energy combinations and dose levels. The influence of beam hardening effects and the performance of a beam hardening correction were investigated. In addition, two systems from different manufacturers were compared in terms of errors in the extracted effective atomic numbers ([Formula: see text]) and relative electron densities ([Formula: see text]) for phantom inserts with known elemental compositions and relative electron densities...
September 28, 2016: British Journal of Radiology
Simon van Kranen, Olga Hamming-Vrieze, Annelisa Wolf, Eugène Damen, Marcel van Herk, Jan-Jakob Sonke
PURPOSE: We set out to investigate loss of target coverage from anatomy changes in head and neck cancer patients as a function of applied safety margins and to verify a cone beam computed tomography (CBCT)-based adaptive strategy with an average patient anatomy to overcome possible target underdosage. METHODS AND MATERIALS: For 19 oropharyngeal cancer patients, volumetric modulated arc therapy treatment plans (2 arcs; simultaneous integrated boost, 70 and 54.25 Gy; 35 fractions) were automatically optimized with uniform clinical target volume (CTV)-to-planning target volume margins of 5, 3, and 0 mm...
November 1, 2016: International Journal of Radiation Oncology, Biology, Physics
Shisuo Du, Virginia Lockamy, Lin Zhou, Christine Xue, Justin LeBlanc, Shonna Glenn, Gaurav Shukla, Yan Yu, Adam P Dicker, Dennis B Leeper, You Lu, Bo Lu
PURPOSE: To implement clinical stereotactic body radiation therapy (SBRT) using a small animal radiation research platform (SARRP) in a genetically engineered mouse model of lung cancer. METHODS AND MATERIALS: A murine model of multinodular Kras-driven spontaneous lung tumors was used for this study. High-resolution cone beam computed tomography (CBCT) imaging was used to identify and target peripheral tumor nodules, whereas off-target lung nodules in the contralateral lung were used as a nonirradiated control...
November 1, 2016: International Journal of Radiation Oncology, Biology, Physics
R Yeung, J Sidney, R Ferris, J Soo, M C Liu
No abstract text is available yet for this article.
October 1, 2016: International Journal of Radiation Oncology, Biology, Physics
Luis Munoz, Amy Ziebell, Jason Morton, Madhava Bhat
An in-house solution for the verification of dose delivered to a moving phantom as required for the clinical implementation of lung stereotactic ablative body radiation therapy was developed. The superior-inferior movement required to simulate tumour motion during a normal breathing cycle was achieved via the novel use of an Arduino Uno™, a low-cost open-source microcontroller board connected to a high torque servo motor. Slow CT imaging was used to acquire the image set and a 4D cone beam CT (4D-CBCT) verified the efficacy of contoured margins before treatment on the moving phantom...
September 15, 2016: Australasian Physical & Engineering Sciences in Medicine
Cyril Mory, Guillaume Janssens, Simon Rit
Four-dimensional cone-beam computed tomography (4D-CBCT) of the free-breathing thorax is a valuable tool in image-guided radiation therapy of the thorax and the upper abdomen. It allows the determination of the position of a tumor throughout the breathing cycle, while only its mean position can be extracted from three-dimensional CBCT. The classical approaches are not fully satisfactory: respiration-correlated methods allow one to accurately locate high-contrast structures in any frame, but contain strong streak artifacts unless the acquisition is significantly slowed down...
September 21, 2016: Physics in Medicine and Biology
Yuru Pei, Xingsheng Ai, Hongbin Zha, Tianmin Xu, Gengyu Ma
PURPOSE: Tooth segmentation is an essential step in acquiring patient-specific dental geometries from cone-beam computed tomography (CBCT) images. Tooth segmentation from CBCT images is still a challenging task considering the comparatively low image quality caused by the limited radiation dose, as well as structural ambiguities from intercuspation and nearby alveolar bones. The goal of this paper is to present and discuss the latest accomplishments in semisupervised tooth segmentation with adaptive 3D shape constraints...
September 2016: Medical Physics
Verónica García-Vázquez, Eugenio Marinetto, Pedro Guerra, Manlio Fabio Valdivieso-Casique, Felipe Ángel Calvo, Eduardo Alvarado-Vásquez, Claudio Vicente Sole, Kirby Gannett Vosburgh, Manuel Desco, Javier Pascau
Intraoperative electron radiation therapy (IOERT) involves irradiation of an unresected tumour or a post-resection tumour bed. The dose distribution is calculated from a preoperative computed tomography (CT) study acquired using a CT simulator. However, differences between the actual IOERT field and that calculated from the preoperative study arise as a result of patient position, surgical access, tumour resection and the IOERT set-up. Intraoperative CT imaging may then enable a more accurate estimation of dose distribution...
August 23, 2016: Zeitschrift Für Medizinische Physik
Azadeh A T Borojeni, Dennis O Frank-Ito, Julia S Kimbell, John S Rhee, Guilherme J M Garcia
Virtual surgery planning based on computational fluid dynamics (CFD) simulations has the potential to improve surgical outcomes for nasal airway obstruction (NAO) patients, but the benefits of virtual surgery planning must outweigh the risks of radiation exposure. Cone beam computed tomography (CBCT) scans represent an attractive imaging modality for virtual surgery planning due to lower costs and lower radiation exposures compared with conventional CT scans. However, to minimize the radiation exposure, the CBCT sinusitis protocol sometimes images only the nasal cavity, excluding the nasopharynx...
August 15, 2016: International Journal for Numerical Methods in Biomedical Engineering
Aurélien Corroyer-Dulmont, Nadia Falzone, Veerle Kersemans, James Thompson, Mark Hill, P Danny Allen, John Beech, Stuart Gilchrist, Paul Kinchesh, Boris Vojnovic, Iain Tullis, Mark Gaze, Sean Smart, Katherine A Vallis
OBJECTIVE: Neuroblastoma has one of the lowest survival rates of all childhood cancers despite the use of intensive treatment regimens. Preclinical models of neuroblastoma are essential for testing new multimodality protocols, including those that involve radiotherapy (RT). The aim of this study was to develop a robust method for RT planning and tumour response monitoring based on combined MRI and cone beam CT (CBCT) imaging and to apply it to a widely studied mouse xenograft model of neuroblastoma, SK-N-SH...
August 15, 2016: British Journal of Radiology
R de Crevoisier, B Chauvet, I Barillot, C Lafond, M Mahé, G Delpon
The IGRT is described in its various equipment and implementation. IGRT can be based either on ionizing radiation generating 2D imaging (MV or kV) or 3D imaging (CBCT or MV-CT) or on non-ionizing radiation (ultrasound, optical imaging, MRI or radiofrequency). Adaptive radiation therapy is then presented in its principles of implementation. The function of the technicians for IGRT is then presented and the possible dose delivered by the on-board imaging is discussed. The quality control of IGRT devices is finally described...
September 2016: Cancer Radiothérapie: Journal de la Société Française de Radiothérapie Oncologique
Victor Razafindranaly, Eric Truy, Jean-Baptiste Pialat, Amanda Martinon, Magali Bourhis, Nawele Boublay, Frédéric Faure, Aïcha Ltaïef-Boudrigua
OBJECTIVE: To evaluate the diagnostic concordance between multislice computed tomography (MSCT) and cone beam computed tomography (CBCT) in the early postoperative assessment of patients after cochlear implantation. STUDY DESIGN: Prospective, randomized, single-center, interventional, pilot study on the diagnostic performance of a medical device. SETTING: Tertiary referral center. PATIENTS: Patients aged over 18 years requiring a computed tomographic (CT) scan after cochlear implant surgery...
October 2016: Otology & Neurotology
Awet Z Kibrom, Kellie A Knight
Significant changes in the shape, size and position of the bladder during radiotherapy (RT) treatment for bladder cancer have been correlated with high local failure rates; typically due to geographical misses. To account for this, large margins are added around the target volumes in conventional RT; however, this increases the volume of healthy tissue irradiation. The availability of cone beam computed tomography (CBCT) has not only allowed in-room volumetric imaging of the bladder, but also the development of adaptive radiotherapy (ART) for modification of plans to patient-specific changes...
December 2015: Journal of Medical Radiation Sciences
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