keyword
MENU ▼
Read by QxMD icon Read
search

Radiotherapy contouring atlas

keyword
https://www.readbyqxmd.com/read/28048133/su-f-j-113-multi-atlas-based-automatic-organ-segmentation-for-lung-radiotherapy-planning
#1
J Kim, J Han, S Ailawadi, J Baker, A Hsia, Z Xu, S Ryu
PURPOSE: Normal organ segmentation is one time-consuming and labor-intensive step for lung radiotherapy treatment planning. The aim of this study is to evaluate the performance of a multi-atlas based segmentation approach for automatic organs at risk (OAR) delineation. METHODS: Fifteen Lung stereotactic body radiation therapy patients were randomly selected. Planning CT images and OAR contours of the heart - HT, aorta - AO, vena cava - VC, pulmonary trunk - PT, and esophagus - ES were exported and used as reference and atlas sets...
June 2016: Medical Physics
https://www.readbyqxmd.com/read/28048041/su-f-j-34-automatic-target-based-patient-positioning-framework-for-image-guided-radiotherapy-in-prostate-cancer-treatment
#2
M Sasahara, H Arimura, Y Shibayama, T Hirose, S Ohga, Y Umezu, H Honda, T Sasaki
PURPOSE: Current image-guided radiotherapy (IGRT) procedure is bonebased patient positioning, followed by subjective manual correction using cone beam computed tomography (CBCT). This procedure might cause the misalignment of the patient positioning. Automatic target-based patient positioning systems achieve the better reproducibility of patient setup. Our aim of this study was to develop an automatic target-based patient positioning framework for IGRT with CBCT images in prostate cancer treatment...
June 2016: Medical Physics
https://www.readbyqxmd.com/read/28047965/tu-h-campus-jep2-05-can-automatic-delineation-of-cardiac-substructures-on-noncontrast-ct-be-used-for-cardiac-toxicity-analysis
#3
Y Luo, Z Liao, W Jiang, D Gomez, R Williamson, L Court, J Yang
PURPOSE: To evaluate the feasibility of using an automatic segmentation tool to delineate cardiac substructures from computed tomography (CT) images for cardiac toxicity analysis for non-small cell lung cancer (NSCLC) patients after radiotherapy. METHODS: A multi-atlas segmentation tool developed in-house was used to delineate eleven cardiac substructures including the whole heart, four heart chambers, and six greater vessels automatically from the averaged 4DCT planning images for 49 NSCLC patients...
June 2016: Medical Physics
https://www.readbyqxmd.com/read/28047834/su-c-bra-04-automated-segmentation-of-head-and-neck-ct-images-for-radiotherapy-treatment-planning-via-multi-atlas-machine-learning-maml
#4
X Ren, G Sharp, H Gao
PURPOSE: Accurate image segmentation is a crucial step during image guided radiation therapy. This work proposes multi-atlas machine learning (MAML) algorithm for automated segmentation of head-and-neck CT images. METHODS: As the first step, the algorithm utilizes normalized mutual information as similarity metric, affine registration combined with multiresolution B-Spline registration, and then fuses together using the label fusion strategy via Plastimatch. As the second step, the following feature selection strategy is proposed to extract five feature components from reference or atlas images: intensity (I), distance map (D), box (B), center of gravity (C) and stable point (S)...
June 2016: Medical Physics
https://www.readbyqxmd.com/read/28047301/tu-ab-202-10-how-effective-are-current-atlas-selection-methods-for-atlas-based-auto-contouring-in-radiotherapy-planning
#5
D Peressutti, B Schipaanboord, J van Soest, T Lustberg, W van Elmpt, T Kadir, A Dekker, M Gooding
PURPOSE: To investigate the effectiveness of atlas selection methods for improving atlas-based auto-contouring in radiotherapy planning. METHODS: 275 H&N clinically delineated cases were employed as an atlas database from which atlases would be selected. A further 40 previously contoured cases were used as test patients against which atlas selection could be performed and evaluated. 26 variations of selection methods proposed in the literature and used in commercial systems were investigated...
June 2016: Medical Physics
https://www.readbyqxmd.com/read/28047055/su-g-jep2-06-dosimetric-and-workflow-evaluation-of-first-commercial-synthetic-ct-software-for-clinical-use-in-pelvis
#6
N Tyagi, J Zhang, L Happersett, M Kadbi, J Mechalakos, J Deasy, M Hunt
PURPOSE: evaluate a commercial synthetic CT (syn-CT) software for use in prostate radiotherapy METHODS: Twenty prostate patients underwent CT and MR simulation scans in treatment position on a 3T Philips scanner. The MR protocol consisted of a T2w turbo spin-echo for soft tissue contrast, a 2D balanced-fast field echo (b-FFE) for fiducial identification, a dual-echo 3D FFE B0 map for distortion analysis and a 3D mDIXON FFE sequence to generate syn-CT. Two echoes are acquired during mDIXON scan, allowing water, fat, and in-phase images to be derived using the frequency shift of the fat and water protons...
June 2016: Medical Physics
https://www.readbyqxmd.com/read/28046433/we-h-202-03-accounting-for-large-geometric-changes-during-radiotherapy
#7
G Hugo
: Deformable image registration has now been commercially available for several years, with solid performance in a number of sites and for several applications including contour and dose mapping. However, more complex applications have arisen, such as assessing response to radiation therapy over time, registering images pre- and post-surgery, and auto-segmentation from atlases. These applications require innovative registration algorithms to achieve accurate alignment. The goal of this session is to highlight emerging registration technology and these new applications...
June 2016: Medical Physics
https://www.readbyqxmd.com/read/27992058/an-mri-compatible-patient-rotation-system-design-construction-and-first-organ-deformation-results
#8
Brendan Whelan, Gary Liney, Jason A Dowling, Robba Rai, Lois Holloway, Leigh McGarvie, Ilana Feain, Megan Berry, Michael Barton, Rob Wilkins, Paul Keall
PURPOSE: Conventionally in radiotherapy, a very heavy beam forming apparatus (gantry) is rotated around a patient. From a mechanical perspective, a more elegant approach is to rotate the patient within a stationary beam. Key obstacles to this approach are patient tolerance and anatomical deformation. Very little information on either aspect is available in the literature. The purpose of this work was therefore to design and test an MRI compatible patient rotation system such that the feasibility of a patient rotation workflow could be tested...
December 19, 2016: Medical Physics
https://www.readbyqxmd.com/read/27991439/augmenting-atlas-based-liver-segmentation-for-radiotherapy-treatment-planning-by-incorporating-image-features-proximal-to-the-atlas-contours
#9
Dengwang Li, Li Liu, Jinhu Chen, Hongsheng Li, Yong Yin, Bulat Ibragimov, Lei Xing
Atlas-based segmentation utilizes a library of previously delineated contours of similar cases to facilitate automatic segmentation. The problem, however, remains challenging because of limited information carried by the contours in the library. In this studying, we developed a narrow-shell strategy to enhance the information of each contour in the library and to improve the accuracy of the exiting atlas-based approach. This study presented a new concept of atlas based segmentation method. Instead of using the complete volume of the target organs, only information along the organ contours from the atlas images was used for guiding segmentation of the new image...
January 7, 2017: Physics in Medicine and Biology
https://www.readbyqxmd.com/read/27797223/hippocampal-sparing-whole-brain-radiotherapy-and-integrated-simultaneous-boost-vs-stereotactic-radiosurgery-boost-a-comparative-dosimetric-planning-study
#10
Soon Keat Cheah, Thomas Matthews, Bin Sing Teh
BACKGROUND: Whole brain radiotherapy (WBRT) and stereotactic radiosurgery were frequently used to palliate patients with brain metastases. It remains controversial which modality or combination of therapy is superior especially in the setting of limited number of brain metastases. The availability of newer medical therapy that improves survival highlighted the importance of reducing long term radiation toxicity associated with WBRT. In this study, we aim to demonstrate the hippocampal sparing technique with whole brain and integrated simultaneous boost Materials and Methods: Planning data from 10 patients with 1-5 brain metastases treated with SRS were identified...
2016: Asian Pacific Journal of Cancer Prevention: APJCP
https://www.readbyqxmd.com/read/27570583/quantitative-assessment-of-target-delineation-variability-for-thymic-cancers-agreement-evaluation-of-a-prospective-segmentation-challenge
#11
Emma Holliday, Clifton D Fuller, Jayashree Kalpathy-Cramer, Daniel Gomez, Andreas Rimner, Ying Li, Suresh Senan, Lynn D Wilson, Jehee Choi, Ritsuko Komaki, Charles R Thomas
OBJECTIVES: We sought to quantitatively determine the inter-observer variability of expert radiotherapy target-volume delineation for thymic cancers, as part of a larger effort to develop an expert-consensus contouring atlas. METHODS: A pilot dataset was created consisting of a standardized case presentation with pre- and post-operative DICOM CT image sets from a single patient with Masaoka-Koga Stage III thymoma. Expert thoracic radiation oncologists delineated tumor targets on the pre- and post-operative scans as they would for a definitive and adjuvant case, respectively...
March 2016: Journal of Radiation Oncology
https://www.readbyqxmd.com/read/27536556/comparison-of-automated-atlas-based-segmentation-software-for-postoperative-prostate-cancer-radiotherapy
#12
Grégory Delpon, Alexandre Escande, Timothée Ruef, Julien Darréon, Jimmy Fontaine, Caroline Noblet, Stéphane Supiot, Thomas Lacornerie, David Pasquier
Automated atlas-based segmentation (ABS) algorithms present the potential to reduce the variability in volume delineation. Several vendors offer software that are mainly used for cranial, head and neck, and prostate cases. The present study will compare the contours produced by a radiation oncologist to the contours computed by different automated ABS algorithms for prostate bed cases, including femoral heads, bladder, and rectum. Contour comparison was evaluated by different metrics such as volume ratio, Dice coefficient, and Hausdorff distance...
2016: Frontiers in Oncology
https://www.readbyqxmd.com/read/27487892/a-patch-based-pseudo-ct-approach-for-mri-only-radiotherapy-in-the-pelvis
#13
Daniel Andreasen, Koen Van Leemput, Jens M Edmund
PURPOSE: In radiotherapy based only on magnetic resonance imaging (MRI), knowledge about tissue electron densities must be derived from the MRI. This can be achieved by converting the MRI scan to the so-called pseudo-computed tomography (pCT). An obstacle is that the voxel intensities in conventional MRI scans are not uniquely related to electron density. The authors previously demonstrated that a patch-based method could produce accurate pCTs of the brain using conventional T1-weighted MRI scans...
August 2016: Medical Physics
https://www.readbyqxmd.com/read/27455480/the-feasibility-of-atlas-based-automatic-segmentation-of-mri-for-h-n-radiotherapy-planning
#14
Kieran Wardman, Robin J D Prestwich, Mark J Gooding, Richard J Speight
Atlas-based autosegmentation is an established tool for segmenting structures for CT-planned head and neck radiotherapy. MRI is being increasingly integrated into the planning process. The aim of this study is to assess the feasibility of MRI-based, atlas-based autosegmentation for organs at risk (OAR) and lymph node levels, and to compare the segmentation accuracy with CT-based autosegmentation. Fourteen patients with locally advanced head and neck cancer in a prospective imaging study underwent a T1-weighted MRI and a PET-CT (with dedicated contrast-enhanced CT) in an immobilization mask...
July 8, 2016: Journal of Applied Clinical Medical Physics
https://www.readbyqxmd.com/read/27044498/genital-invasion-or-perigenital-spread-may-pose-a-risk-of-marginal-misses-for-intensity-modulated-radiotherapy-imrt-in-anal-cancer
#15
Julia Koeck, Frank Lohr, Daniel Buergy, Karen Büsing, Marcus J Trunk, Frederik Wenz, Sabine Mai
BACKGROUND: While intensity modulated radiotherapy (IMRT) in anal cancer is feasible and improves high-dose conformality, the current RTOG/AGITG contouring atlas and planning guidelines lack specific instructions on how to proceed with external genitalia. Meanwhile, the RTOG-Protocol 0529 explicitly recommends genital sparing on the basis of specific genital dose constraints. Recent pattern-of-relapse studies based on conventional techniques suggest that marginal miss might be a potential consequence of genital sparing...
April 4, 2016: Radiation Oncology
https://www.readbyqxmd.com/read/26970676/assessment-of-fully-automated-atlas-based-segmentation-of-novel-oral-mucosal-surface-organ-at-risk
#16
Jamie A Dean, Liam C Welsh, Dualta McQuaid, Kee H Wong, Aleksandar Aleksic, Emma Dunne, Mohammad R Islam, Anushka Patel, Priyanka Patel, Imran Petkar, Iain Phillips, Jackie Sham, Kate L Newbold, Shreerang A Bhide, Kevin J Harrington, Sarah L Gulliford, Christopher M Nutting
BACKGROUND AND PURPOSE: Current oral mucositis normal tissue complication probability models, based on the dose distribution to the oral cavity volume, have suboptimal predictive power. Improving the delineation of the oral mucosa is likely to improve these models, but is resource intensive. We developed and evaluated fully-automated atlas-based segmentation (ABS) of a novel delineation technique for the oral mucosal surfaces. MATERIAL AND METHODS: An atlas of mucosal surface contours (MSC) consisting of 46 patients was developed...
April 2016: Radiotherapy and Oncology: Journal of the European Society for Therapeutic Radiology and Oncology
https://www.readbyqxmd.com/read/26831922/pancreatic-cancer-planning-complex-conformal-vs-modulated-therapies
#17
Katherine L Chapman, Matthew E Witek, Hongyu Chen, Timothy N Showalter, Voichita Bar-Ad, Amy S Harrison
To compare the roles of intensity-modulated radiation therapy (IMRT) and volumetric- modulated arc therapy (VMAT) therapy as compared to simple and complex 3-dimensional chemoradiotherpy (3DCRT) planning for resectable and borderline resectable pancreatic cancer. In all, 12 patients who received postoperative radiotherapy (8) or neoadjuvant concurrent chemoradiotherapy (4) were evaluated retrospectively. Radiotherapy planning was performed for 4 treatment techniques: simple 4-field box, complex 5-field 3DCRT, 5 to 6-field IMRT, and single-arc VMAT...
2016: Medical Dosimetry: Official Journal of the American Association of Medical Dosimetrists
https://www.readbyqxmd.com/read/26328953/validation-of-clinical-acceptability-of-an-atlas-based-segmentation-algorithm-for-the-delineation-of-organs-at-risk-in-head-and-neck-cancer
#18
Albert K Hoang Duc, Gemma Eminowicz, Ruheena Mendes, Swee-Ling Wong, Jamie McClelland, Marc Modat, M Jorge Cardoso, Alex F Mendelson, Catarina Veiga, Timor Kadir, Derek D'Souza, Sebastien Ourselin
PURPOSE: The aim of this study was to assess whether clinically acceptable segmentations of organs at risk (OARs) in head and neck cancer can be obtained automatically and efficiently using the novel "similarity and truth estimation for propagated segmentations" (STEPS) compared to the traditional "simultaneous truth and performance level estimation" (STAPLE) algorithm. METHODS: First, 6 OARs were contoured by 2 radiation oncologists in a dataset of 100 patients with head and neck cancer on planning computed tomography images...
September 2015: Medical Physics
https://www.readbyqxmd.com/read/26206715/supervised-machine-learning-based-classification-scheme-to-segment-the-brainstem-on-mri-in-multicenter-brain-tumor-treatment-context
#19
Jose Dolz, Anne Laprie, Soléakhéna Ken, Henri-Arthur Leroy, Nicolas Reyns, Laurent Massoptier, Maximilien Vermandel
PURPOSE: To constrain the risk of severe toxicity in radiotherapy and radiosurgery, precise volume delineation of organs at risk is required. This task is still manually performed, which is time-consuming and prone to observer variability. To address these issues, and as alternative to atlas-based segmentation methods, machine learning techniques, such as support vector machines (SVM), have been recently presented to segment subcortical structures on magnetic resonance images (MRI). METHODS: SVM is proposed to segment the brainstem on MRI in multicenter brain cancer context...
January 2016: International Journal of Computer Assisted Radiology and Surgery
https://www.readbyqxmd.com/read/26142269/atlas-of-the-thoracic-lymph-nodal-delineation-and-recommendations-for-lymph-nodal-ctv-of-esophageal-squamous-cell-cancer-in-radiation-therapy-from-china
#20
Wei Huang, Yong Huang, Jujie Sun, Xibin Liu, Jian Zhang, Tao Zhou, Baijiang Zhang, Baosheng Li
PURPOSE: To construct an anatomical atlas of thoracic lymph node regions of esophageal cancer (EC) based on definitions from The Japan Esophageal Society (JES) and generate a consensus to delineate the nodal clinical target volume (CTVn) for elective nodal radiation (ENI) of esophageal squamous cell carcinoma (ESCC). METHODS AND MATERIALS: An interdisciplinary group including two dedicated radiation oncologists, an experienced radiologist, a pathologist and two thoracic surgeons were gathered to generate a three-dimensional radiological description for the mediastinal lymph node regions of EC on axial CT scans...
July 2015: Radiotherapy and Oncology: Journal of the European Society for Therapeutic Radiology and Oncology
keyword
keyword
48952
1
2
Fetch more papers »
Fetching more papers... Fetching...
Read by QxMD. Sign in or create an account to discover new knowledge that matter to you.
Remove bar
Read by QxMD icon Read
×

Search Tips

Use Boolean operators: AND/OR

diabetic AND foot
diabetes OR diabetic

Exclude a word using the 'minus' sign

Virchow -triad

Use Parentheses

water AND (cup OR glass)

Add an asterisk (*) at end of a word to include word stems

Neuro* will search for Neurology, Neuroscientist, Neurological, and so on

Use quotes to search for an exact phrase

"primary prevention of cancer"
(heart or cardiac or cardio*) AND arrest -"American Heart Association"