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https://www.readbyqxmd.com/read/28898423/iterative-volume-of-interest-based-4d-cone-beam-ct
#1
Rachael Martin, Moiz Ahmad, Geoffrey Hugo, Tinsu Pan
PURPOSE: 4D cone-beam CT (CBCT) has potential applications in soft tissue alignment and tumor motion verification at the time of radiation treatment. However, prominent streak artifacts with conventional image reconstructions have limited its clinical use and alternative reconstructions are generally too computationally expensive for the time available. We propose an iterative volume of interest based (I4D VOI) reconstruction technique, where 4D reconstruction is only performed within a VOI, to limit streak artifacts with limited added computation time...
September 12, 2017: Medical Physics
https://www.readbyqxmd.com/read/28890818/individualized-4-dimensional-computed-tomography-proton-treatment-for-pancreatic-tumors
#2
Matthew L Knecht, Ning Wang, April Vassantachart, Rachel Mifflin, Jerry D Slater, Gary Y Yang
BACKGROUND: The goal of this study is to determine whether a phase or reconstruction of a 10-phase 4 dimensional computed tomography (4D CT) scan can be used as the primary planning scan for proton treatment of the pancreas, thus eliminating the need for second a slow CT or free breathing CT. METHODS: Ten patients with pancreatic adenocarcinoma were simulated with 4D CT and a proton treatment plan generated based upon one of three primary planning scans, the T0 phase, T50 phase or average reconstruction...
August 2017: Journal of Gastrointestinal Oncology
https://www.readbyqxmd.com/read/28886071/dynamics-of-the-aortic-annulus-in-4d-ct-angiography-for-transcatheter-aortic-valve-implantation-patients
#3
Mustafa A Elattar, Leon W Vink, Martijn S van Mourik, Jan Baan, Ed T vanBavel, R Nils Planken, Henk A Marquering
BACKGROUND: Transcatheter aortic valve implantation (TAVI) is a well-established treatment for patients with severe aortic valve stenosis. This procedure requires pre-operative planning by assessment of aortic dimensions on CT Angiography (CTA). It is well-known that the aortic root dimensions vary over the heart cycle. However, sizing is commonly performed at either mid-systole or end-diastole only, which has resulted in an inadequate understanding of its full dynamic behavior. STUDY GOAL: We studied the variation in annulus measurements during the cardiac cycle and determined if this variation is dependent on the amount of calcification at the annulus...
2017: PloS One
https://www.readbyqxmd.com/read/28885090/difference-in-target-definition-using-three-different-methods-to-include-respiratory-motion-in-radiotherapy-of-lung-cancer
#4
Ditte Sloth Møller, Marianne Marquard Knap, Tine Bisballe Nyeng, Azza Ahmed Khalil, Marianne Ingerslev Holt, Maria Kandi, Lone Hoffmann
INTRODUCTION: Minimizing the planning target volume (PTV) while ensuring sufficient target coverage during the entire respiratory cycle is essential for free-breathing radiotherapy of lung cancer. Different methods are used to incorporate the respiratory motion into the PTV. MATERIAL AND METHODS: Fifteen patients were analyzed. Respiration can be included in the target delineation process creating a respiratory GTV, denoted iGTV. Alternatively, the respiratory amplitude (A) can be measured based on the 4D-CT and A can be incorporated in the margin expansion...
September 8, 2017: Acta Oncologica
https://www.readbyqxmd.com/read/28877531/towards-individualized-tracheobronchial-stents-technical-practical-and-legal-considerations
#5
Lutz Freitag, Martin Gördes, Paul Zarogoulidis, Kaid Darwiche, Daniel Franzen, Faustina Funke, Wolfgang Hohenforst-Schmidt, Hervé Dutau
Stent placement has been established as a standard procedure for treating airway obstructions. Other indications are localized malacias and fistulas. Though many different stents with various diameters and lengths are available, the shapes are hardly ever ideal because of the distorted anatomy in patients with diseased airways. There are technical and legal limitations for customizing purchased airway stents. Individually tailored stents would be preferable. New techniques of additive manufacturing such as 3D printing make it possible to produce optimized stents for a particular patient...
September 7, 2017: Respiration; International Review of Thoracic Diseases
https://www.readbyqxmd.com/read/28872050/super-resolution-reconstruction-of-4d-ct-lung-data-via-patch-based-low-rank-matrix-reconstruction
#6
Shiting Fang, Huafeng Wang, Yueliang Liu, Minghui Zhang, Wei Yang, Qianjin Feng, Wufan Chen, Yu Zhang
Lung 4D computed tomography (4D-CT), which is a time-resolved CT data acquisition, performs an important role in explicitly including respiratory motion in treatment planning and delivery. However, the radiation dose is usually reduced at the expense of inter-slice spatial resolution to minimize radiation-related health risk. Therefore, resolution enhancement along the superior-inferior direction is necessary. Methods: In this paper, a super-resolution (SR) reconstruction method based on a patch low-rank matrix reconstruction is proposed to improve the resolution of lung 4D-CT images...
September 5, 2017: Physics in Medicine and Biology
https://www.readbyqxmd.com/read/28871982/evaluating-the-toxicity-reduction-with-computed-tomographic-ventilation-functional-avoidance-radiation-therapy
#7
Austin M Faught, Yuya Miyasaka, Noriyuki Kadoya, Richard Castillo, Edward Castillo, Yevgeniy Vinogradskiy, Tokihiro Yamamoto
PURPOSE: Computed tomographic (CT) ventilation imaging is a new modality that uses 4-dimensional (4D) CT information to calculate lung ventilation. Although retrospective studies have reported on the reduction in dose to functional lung, no work to our knowledge has been published in which the dosimetric improvements have been translated to a reduction in the probability of pulmonary toxicity. Our work estimates the reduction in toxicity for CT ventilation-based functional avoidance planning...
October 1, 2017: International Journal of Radiation Oncology, Biology, Physics
https://www.readbyqxmd.com/read/28870227/cone-beam-ct-reconstruction-for-non-periodic-organ-motion-using-time-ordered-chain-graph-model
#8
Masahiro Nakano, Akihiro Haga, Jun'ichi Kotoku, Taiki Magome, Yoshitaka Masutani, Shouhei Hanaoka, Satoshi Kida, Keiichi Nakagawa
PURPOSE: The purpose of this study is to introduce the new concept of a four-dimensional (4D) cone-beam computed tomography (CBCT) reconstruction approach for non-periodic organ motion in cooperation with the time-ordered chain graph model (TCGM) and to compare it with previously developed methods such as total variation-based compressed sensing (TVCS) and prior-image constrained compressed sensing (PICCS). MATERIALS AND METHODS: Our proposed reconstruction is based on a model including the constraint originating from the images of neighboring time phases...
September 4, 2017: Radiation Oncology
https://www.readbyqxmd.com/read/28845691/four-dimensional-ct-angiography-4d-cta-in-the-evaluation-of-juvenile-nasopharyngeal-angiofibromas-comparison-with-digital-subtraction-angiography-dsa-and-surgical-findings
#9
Zebin Xiao, Yingyan Zheng, Jian Li, Dehua Chen, Fang Liu, Dairong Cao
OBJECTIVES: To explore the value of four-dimensional CT angiography (4D-CTA) in the preoperative evaluation of JNAs using 320-row volume CT. METHODS: 4D-CTA and DSA data of 18 patients with histopathologically proven JNAs were retrospectively reviewed. The location, extent, feeding vessels and stage of JNAs were assessed by two radiologists independently and blindly. The agreements between both reviewers and between 4D-CTA and surgical findings for assessing the above indicators were analyzed respectively...
August 27, 2017: Dento Maxillo Facial Radiology
https://www.readbyqxmd.com/read/28843397/experimental-validation-of-a-4d-dose-calculation-routine-for-pencil-beam-scanning-proton-therapy
#10
T Pfeiler, C Bäumer, E Engwall, D Geismar, B Spaan, B Timmermann
Respiratory induced organ motion poses a major challenge for high-precision radiotherapy such as pencil beam scanning proton therapy (PBS). In order to employ PBS for target regions affected by respiratory motion, the implementation of dedicated motion mitigation techniques should be considered and residual uncertainties need to be assessed. For the latter purpose, a routine simulating the delivery of a scanned proton beam to a moving target was developed and implemented in the commercial treatment planning system RayStation...
August 23, 2017: Zeitschrift Für Medizinische Physik
https://www.readbyqxmd.com/read/28833248/real-time-respiratory-phase-matching-between-2d-fluoroscopic-images-and-3d-ct-images-for-precise-percutaneous-lung-biopsy
#11
Chijun Weon, Mina Kim, Chang Min Park, Jong Beom Ra
PURPOSE: A 3D CT image is used along with real-time 2D fluoroscopic images in the state-of-the-art cone-beam CT system to guide percutaneous lung biopsy (PLB). To improve the guiding accuracy by compensating for respiratory motion, we propose an algorithm for real-time matching of 2D fluoroscopic images to multiple 3D CT images of different respiratory phases that is robust to the small movement and deformation due to cardiac motion. METHODS: Based on the transformations obtained from non-rigid registration between two 3D CT images acquired at expiratory and inspiratory phases, we first generate sequential 3D CT images (or a 4D CT image) and the corresponding 2D digitally reconstructed radiographs (DRRs) of vessels...
August 20, 2017: Medical Physics
https://www.readbyqxmd.com/read/28817381/advanced-radiation-dosimetry-phantom-ardos-a-versatile-breathing-phantom-for-4d-radiation-therapy-and-medical-imaging
#12
Natalia Kostiukhina, Dietmar Georg, Sofia Rollet, Peter Kuess, Andrej Sipaj, Piotr Andrzejewski, Hugo Furtado, Ivo Rausch, Wolfgang Lechner, Elisabeth Steiner, Hunor Kertesz, Barbara Knaeusl
A novel breathing phantom was designed for being used in conventional and ion-beam radiotherapy as well as for medical imaging. Accurate dose delivery and patient safety are aimed to be verified for four-dimensional (4D) treatment techniques compensating for breathing-induced tumor motion. The phantom includes anthropomorphic components representing an average human thorax. It consists of real tissue equivalent materials to fulfill the requirements for dosimetric experiments and imaging purposes. The different parts of the torso (lungs, chest wall, and ribs) and the tumor can move independently...
August 17, 2017: Physics in Medicine and Biology
https://www.readbyqxmd.com/read/28816147/evaluating-which-dose-function-metrics-are-most-critical-for-functional-guided-radiation-therapy
#13
Austin M Faught, Tokihiro Yamamoto, Richard Castillo, Edward Castillo, Jingjing Zhang, Moyed Miften, Yevgeniy Vinogradskiy
PURPOSE: Four-dimensional (4D) computed tomography (CT) ventilation imaging is increasingly being used to calculate lung ventilation and implement functional-guided radiation therapy in clinical trials. There has been little exhaustive work evaluating which dose-function metrics should be used for treatment planning and plan evaluation. The purpose of our study was to evaluate which dose-function metrics best predict for radiation pneumonitis (RP). METHODS AND MATERIALS: Seventy lung cancer patients who underwent 4D CT imaging and pneumonitis grading were assessed...
September 1, 2017: International Journal of Radiation Oncology, Biology, Physics
https://www.readbyqxmd.com/read/28797700/4dct-imaging-to-assess-radiomics-feature-stability-an-investigation-for-thoracic-cancers
#14
Ruben T H M Larue, Lien Van De Voorde, Janna E van Timmeren, Ralph T H Leijenaar, Maaike Berbée, Meindert N Sosef, Wendy M J Schreurs, Wouter van Elmpt, Philippe Lambin
BACKGROUND AND PURPOSE: Quantitative tissue characteristics derived from medical images, also called radiomics, contain valuable prognostic information in several tumour-sites. The large number of features available increases the risk of overfitting. Typically test-retest CT-scans are used to reduce dimensionality and select robust features. However, these scans are not always available. We propose to use different phases of respiratory-correlated 4D CT-scans (4DCT) as alternative. MATERIALS AND METHODS: In test-retest CT-scans of 26 non-small cell lung cancer (NSCLC) patients and 4DCT-scans (8 breathing phases) of 20 NSCLC and 20 oesophageal cancer patients, 1045 radiomics features of the primary tumours were calculated...
August 7, 2017: Radiotherapy and Oncology: Journal of the European Society for Therapeutic Radiology and Oncology
https://www.readbyqxmd.com/read/28793141/factors-associated-with-discordance-between-preoperative-parathyroid-4-dimensional-computed-tomographic-scans-and-intraoperative-findings-during-parathyroidectomy
#15
Shonan Sho, Alexander D Yuen, Michael W Yeh, Masha J Livhits, Ali R Sepahdari
Importance: Parathyroid 4-dimensional computed tomographic scans (4D-CTs) have emerged as an accurate and cost-effective initial localization study for patients with primary hyperparathyroidism. However, potential limitations and factors affecting the accuracy of preoperative 4D-CTs remain poorly defined. Objectives: To characterize factors associated with missed parathyroid lesions on preoperative 4D-CTs and to investigate patterns of commonly observed errors. Design, Setting, and Participants: A prospectively accrued patient database was analyzed from September 1, 2011, through October 31, 2016...
August 9, 2017: JAMA Surgery
https://www.readbyqxmd.com/read/28780900/results-from-a-clinical-trial-evaluating-the-efficacy-of-real-time-body-surface-visual-feedback-in-reducing-patient-motion-during-lung-cancer-radiotherapy
#16
Gareth J Price, Corinne Faivre-Finn, Julia Stratford, Sheena Chauhan, Michelle Bewley, Laura Clarke, Corinne N Johnson, Christopher J Moore
INTRODUCTION: Optical surface measurement devices are a maturing technology in radiotherapy. The challenge for such devices is to demonstrate how they can improve clinical care. We present results from a phase 1 clinical trial designed to test the hypothesis that if presented with live data from a novel optical measurement device, showing their deviation from an ideal radiotherapy treatment position, patients will be able to better control their motion and increase their geometrical conformance...
August 7, 2017: Acta Oncologica
https://www.readbyqxmd.com/read/28766726/a-novel-3d-printed-phantom-insert-for-4d-pet-ct-imaging-and-simultaneous-integrated-boost-radiotherapy
#17
Laura Cerviño, Dima Soultan, Mariel Cornell, Adam Yock, Niclas Pettersson, William Y Song, Joseph Aguilera, Sunil Advani, James Murphy, Carl Ho, Claude James, Anthony Paravati, Robin Coope, Bradford Gill, Vitali Moiseenko
PURPOSE: To construct a 3D-printed phantom insert designed to mimic the variable PET tracer uptake seen in lung tumor volumes and a matching dosimetric insert to be used in simultaneous integrated boost (SIB) phantom studies, and to evaluate the design through end-to-end tests. METHODS: A set of phantom inserts was designed and manufactured for a realistic representation of gated radiotherapy steps from 4D PET/CT scanning to dose delivery. A cylindrical phantom (φ80x120 mm) holds inserts for PET/CT scanning...
August 2, 2017: Medical Physics
https://www.readbyqxmd.com/read/28765192/four-dimensional-ct-guided-transcatheter-removal-of-a-fractured-migrated-catheter-of-a-totally-implantable-venous-access-port
#18
Kazushi Fujimoto, Hajime Kasai, Toshihiko Sugiura, Koichiro Tatsumi
Patients undergoing chemotherapy usually undergo placement of a totally implantable venous access port (TIVAP), but TIVAP catheter fracture is rare. We encountered a case where flushing the TIVAP catheter became impossible because of resistance. A 61-year-old-woman underwent TIVAP placement. Although a chest X-ray revealed the fractured catheter had migrated into the right hilar area, the timing of the fracture was unclear. Four-dimensional computed tomography (4D-CT) showed that the tip of the fractured catheter was located at the anterior segmental artery of the right upper lobe and was immobile, with the remaining portion flapping with the blood flow...
August 1, 2017: BMJ Case Reports
https://www.readbyqxmd.com/read/28746180/a-consort-compliant-prospective-randomized-controlled-trial-radiation-dose-reducing-in-computed-tomography-using-an-additional-lateral-scout-view-combined-with-automatic-tube-current-modulation-phantom-and-patient-study
#19
RANDOMIZED CONTROLLED TRIAL
Wanlin Peng, Zhenlin Li, Chunchao Xia, Yingkun Guo, Jinge Zhang, Kai Zhang, Lei Li, Fei Zhao
BACKGROUND: Radiation exposure has been a hot point in research field of computed tomography (CT). Recently, automated tube current modulation (ATCM) has emerged as an important technique to reduce radiation exposure. Many studies have shown that the difference in scout view would affect modulation. This prospective randomized controlled study is aimed to investigate the impact of an additional lateral scout view on radiation dose and image quality in CT using ACTM. METHODS: Combined with ATCM (Care Dose 4D) on multidetector CT, 2 thoracic phantom CT image series were acquired in which planning was conducted with either an anteroposterior (AP) or an AP-lateral scout view...
July 2017: Medicine (Baltimore)
https://www.readbyqxmd.com/read/28741786/ectopic-parathyroid-adenoma-in-the-pyriform-sinus
#20
Jonathan Kim, Maricel Cubangbang, Lacey Adkins, Stanley Chia, Timothy R DeKlotz, Lisa Boyle, Bruce Davidson
BACKGROUND: Ectopic parathyroid glands may complicate the surgical approach to primary hyperparathyroidism. We describe a rare ectopic parathyroid location, the pyriform sinus. METHODS: Three patients, 2 after prior unsuccessful parathyroid exploration, were found to have ectopic parathyroid adenomas in the pyriform sinus. Two cases were identified by 4D-CT of the neck. The other was localized by a technetium 99m sestamibi single photon emission CT (SPECT). In each case, office endoscopy confirmed the lesions...
July 25, 2017: Head & Neck
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