3,557 results match your criteria volumetric scans

Volumetric and dimensional accuracy assessment of CAD-CAM-manufactured dental prostheses from different materials.

J Prosthet Dent 2021 Jul 27. Epub 2021 Jul 27.

Senior Lecturer, Oral rehabilitation Department, Faculty of Dentistry, University Lille Nord de France, Paris, France.

Statement Of Problem: In computer-aided design and computer-aided manufacturing (CAD-CAM) dentistry, the CAD of the prosthesis represents the clinical prerequisite design to restore the treated tooth. However, how closely the CAM prosthesis shape matches the CAD, particularly in relation to different materials, is unclear.

Purpose: The purpose of this in vitro study was to evaluate onlays designed and manufactured with the same CAD-CAM system but manufactured with different materials. Read More

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Ultrasound fusion biopsy.

Radiologe 2021 Jul 29. Epub 2021 Jul 29.

Department of Radiology, Interdisciplinary Ultrasound Center, Campus Charité Mitte, Charité-Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Charitéplatz 1, 10117, Berlin, Germany.

Background: Ultrasound (US)-guided biopsy is widely used for the diagnostic confirmation of focal lesions. For sampling of prostate tissue, magnetic resonance imaging (MRI)/US fusion-guided biopsy has already been implemented in routine clinical practice and has shown a superior detection rate of significant prostate cancer in risk assessment compared with standard systematic biopsy. Newer three-dimensional software tools with volumetric mapping of the prostate and biopsy core channels provide a better overview of systematic biopsy and thus contribute to more accurate treatment planning. Read More

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Volumetric Accuracy Analysis of Virtual Safety Barriers for Cooperative-Control Robotic Mastoidectomy.

Otol Neurotol 2021 Jul 28. Epub 2021 Jul 28.

Department of Otolaryngology-Head and Neck Surgery, Johns Hopkins University School of Medicine Department of Biomedical Engineering Department of Computer Science, Johns Hopkins University Whiting School of Engineering, Baltimore, Maryland.

Hypothesis: Virtual fixtures can be enforced in cooperative-control robotic mastoidectomies with submillimeter accuracy.

Background: Otologic procedures are well-suited for robotic assistance due to consistent osseous landmarks. We have previously demonstrated the feasibility of cooperative-control robots (CCRs) for mastoidectomy. Read More

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CT-based volumetric assessment of rotator cuff muscle in shoulder arthroplasty preoperative planning.

Bone Jt Open 2021 Jul;2(7):552-561

Centre Orthopédique Santy, Lyon, France.

Aims: The aim of this study was to describe a quantitative 3D CT method to measure rotator cuff muscle volume, atrophy, and balance in healthy controls and in three pathological shoulder cohorts.

Methods: In all, 102 CT scans were included in the analysis: 46 healthy, 21 cuff tear arthropathy (CTA), 18 irreparable rotator cuff tear (IRCT), and 17 primary osteoarthritis (OA). The four rotator cuff muscles were manually segmented and their volume, including intramuscular fat, was calculated. Read More

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Morphometric and volumetric analysis of the cervical spinal cord and vertebral canal using computed tomography images in normal Van cats.

Anat Histol Embryol 2021 Jul 27. Epub 2021 Jul 27.

Department of Anatomy, Faculty of Veterinary Medicine, University of Van Yuzuncu Yil, Van, Turkey.

This study was performed on Van cats to determine the volumetric, morphometric and surface area measurement values of their cervical spinal cords (SC) and vertebral canals (CC) and the ratios between their dimensions using computed tomography (CT) images. The study also aims to reveal any biometric differences in these values between the two sexes. Spinal cord and vertebral canal CT images of 16 healthy adult Van cats (8 males and 8 females) were used in the study. Read More

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Age-Dependent Changes in Total and Free Water Content of In Vivo Human Lenses Measured by Magnetic Resonance Imaging.

Invest Ophthalmol Vis Sci 2021 Jul;62(9):33

Department of Physiology, School of Medical Sciences, New Zealand National Eye Centre, University of Auckland, New Zealand.

Purpose: To use magnetic resonance imaging (MRI) to measure age-dependent changes in total and free water in human lenses in vivo.

Methods: Sixty-four healthy adults aged 18 to 86 years were recruited, fitted with a 32-channel head receiver coil, and placed in a 3 Tesla clinical MR scanner. Scans of the crystalline lens were obtained using a volumetric interpolated breath-hold examination sequence with dual flip angles, which were corrected for field inhomogeneity post-acquisition using a B1-map obtained using a turbo-FLASH sequence. Read More

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24-Hour Urine Calcium Oxalate Supersaturation Risk Correlates With CT Volumetric Calcium Oxalate Stone Growth.

J Urol 2021 Jul 21:101097JU0000000000001961. Epub 2021 Jul 21.

Department of Urology, University of Florida, Gainesville, Florida.

Purpose: experiments demonstrate calcium oxalate supersaturation (SS CaOx) drives CaOx nucleation and growth. We investigated the link between 24-hour urine SS CaOx and stone growth through a natural history, imaging study.

Materials And Methods: Using an IRB-approved database, we sought >80% CaOx stone formers who, prior to stone intervention, obtained two separate computed tomograph (CT) scans with at least one 24-hour urine collection between scans. Read More

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Retrospective evaluation of planning margins for patients undergoing radical radiation therapy treatment for bladder cancer using volumetric modulated arc therapy and cone beam computed tomography.

J Med Radiat Sci 2021 Jul 20. Epub 2021 Jul 20.

Mid North Coast Cancer Institute Coffs Harbour, Coffs Harbour, New South Wales, Australia.

Introduction: Current contouring guidelines for curative radiation therapy for muscle-invasive bladder cancer (MIBC) recommend margins of 1.5-2.0 cm, applied to the clinical target volume (CTV). Read More

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Characteristics of expert search behavior in volumetric medical image interpretation.

J Med Imaging (Bellingham) 2021 Jul 14;8(4):041208. Epub 2021 Jul 14.

University of Utah, Department of Psychology, Salt Lake City, Utah, United States.

Experienced radiologists have enhanced global processing ability relative to novices, allowing experts to rapidly detect medical abnormalities without performing an exhaustive search. However, evidence for global processing models is primarily limited to two-dimensional image interpretation, and it is unclear whether these findings generalize to volumetric images, which are widely used in clinical practice. We examined whether radiologists searching volumetric images use methods consistent with global processing models of expertise. Read More

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A multimodal approach to the study of children treated for posterior fossa tumor: A review of the literature and a pilot study.

Clin Neurol Neurosurg 2021 Jul 12;207:106819. Epub 2021 Jul 12.

Scientific Institute Eugenio Medea, Via della Bontà n. 7, 33078 San Vito al Tagliamento, PN, Italy.

Objective: The aims of the present study were: (1) to review the literature on long-lasting cognitive sequelae in children treated for Posterior Fossa Tumor and (2) to investigate anatomic functional relations in a case series of 7 children treated for PFT using magnetic resonance imaging (MRI) post-processing methods.

Methods: We retrospectively analyzed MRIs of children who underwent complete surgical resection of PFT and performed extensive neuropsychological evaluation. Tumor, ventricular volumes, and VPS insertion site were drawn on T1 volumetric MRI scans and normalized to a pediatric template. Read More

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Size-adjustment techniques of lumbar spine dual energy X-ray absorptiometry measurements in assessing bone mineralization in children on maintenance hemodialysis.

J Pediatr Endocrinol Metab 2021 Jul 19. Epub 2021 Jul 19.

Pediatric Nephrology Unit, Department of Pediatrics, Faculty of Medicine, Mansoura University, Mansoura, Egypt.

Objectives: Growing skeleton is uniquely vulnerable to impaired mineralization in chronic kidney disease (CKD). Continued debate exists about the optimal method to adjust for body size when interpreting dual energy X-ray absorptiometry (DXA) scans in children with CKD given the burden of poor growth. The study aimed to evaluate the clinical usefulness of size-adjustment techniques of lumber-spine DXA measurements in assessing bone mineralization in children with kidney failure on maintenance hemodialysis (HD). Read More

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Impact of Intravenously Injected Contrast Agent on Bone Mineral Density Measurement in Dual-Source Dual-Energy CT.

Acad Radiol 2021 Jul 12. Epub 2021 Jul 12.

Division of Experimental Imaging, Department of Diagnostic and Interventional Radiology, University Hospital Frankfurt, Frankfurt am Main, Germany. Electronic address:

Purpose: To assess the influence of intravenously injected contrast agent on bone mineral density (BMD) assessment in dual-source dual-energy CT.

Methods: This retrospective study included 1,031 patients (mean age, 53 ± 7 years; 519 women) who had undergone third-generation dual-source dual-energy CT in context of tumor staging between January 2019 and December 2019. Dedicated postprocessing software based on material decomposition was used for phantomless volumetric BMD assessment of trabecular bone of the lumbar spine. Read More

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J Endod 2021 Jul 12. Epub 2021 Jul 12.

Division of Endodontics, Department of Advanced Oral Sciences and Therapeutics, University of Maryland, School of Dentistry - Baltimore - Maryland, US. Electronic address:

Introduction: To investigate the accuracy and efficiency of the 3D dynamic navigation system (DNS) compared with the freehand technique (FH) when removing fiber posts from root canal treated teeth.

Methods: Twenty-six maxillary teeth were included. Teeth were root canal treated and restored with Parapost Taper Lux (Coltene, Switzerland) luted with RelyX Unicem (3M ESPE, St. Read More

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Small airway dilation measured by endoscopic optical coherence tomography correlates with chronic lung allograft dysfunction.

J Biomed Opt 2021 Jul;26(7)

British Columbia Cancer Research Institute, Department of Integrative Oncology, Imaging Unit, Vancou, Canada.

Significance: Chronic lung allograft dysfunction (CLAD) is the leading cause of death in transplant patients who survive past the first year post-transplant. Current diagnosis is based on sustained decline in lung function; there is a need for tools that can identify CLAD onset.

Aim: Endoscopic optical coherence tomography (OCT) can visualize structural changes in the small airways, which are of interest in CLAD progression. Read More

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Norms for Automatic Estimation of Hippocampal Atrophy and a Step Forward for Applicability to the Italian Population.

Front Neurosci 2021 28;15:656808. Epub 2021 Jun 28.

Laboratory of Neuroinformatics, IRCCS Istituto Centro San Giovanni di Dio Fatebenefratelli, Brescia, Italy.

Introduction: Hippocampal volume is one of the main biomarkers of Alzheimer's Dementia (AD). Over the years, advanced tools that performed automatic segmentation of Magnetic Resonance Imaging (MRI) T13D scans have been developed, such as FreeSurfer (FS) and ACM-Adaboost (AA). Hippocampal volume is considered abnormal when it is below the 5th percentile of the normative population. Read More

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Association of Metformin With Volumetric Tumor Growth of Sporadic Vestibular Schwannomas.

Otol Neurotol 2021 08;42(7):1081-1085

Department of Otolaryngology-Head and Neck Surgery, Mayo Clinic, Rochester, Minnesota.

Objective: Recent research demonstrates a potential association between metformin use and reduced sporadic vestibular schwannoma (VS) growth in patients undergoing conservative observation. The current study was designed to elucidate the effect of metformin on tumor growth in sporadic VS using volumetric analyses.

Study Design: Retrospective cohort. Read More

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Temporally aware volumetric generative adversarial network-based MR image reconstruction with simultaneous respiratory motion compensation: Initial feasibility in 3D dynamic cine cardiac MRI.

Magn Reson Med 2021 Jul 13. Epub 2021 Jul 13.

Department of Radiological Sciences, David Geffen School of Medicine, University of California, Los Angeles, California, USA.

Purpose: Develop a novel three-dimensional (3D) generative adversarial network (GAN)-based technique for simultaneous image reconstruction and respiratory motion compensation of 4D MRI. Our goal was to enable high-acceleration factors 10.7X-15. Read More

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Anterior segment imaging in minimally invasive glaucoma surgery - A systematic review.

Acta Ophthalmol 2021 Jul 11. Epub 2021 Jul 11.

Department of Ophthalmology, Tan Tock Seng Hospital, National Healthcare Group Eye Institute, Singapore, Singapore.

Minimally invasive glaucoma surgery (MIGS) has grown in popularity over the past decade. This systematic review explores the peri-operative and intraoperative application of anterior segment imaging to maximize the efficacy and safety of MIGS. A review of the PubMed, EMBASE and CINAHL databases was conducted, with inclusion criteria restricted to MIGS that had received United States Food and Drug Administration (FDA) premarket approval, FDA 510(K) premarket notification, or were listed as a class 1 device exempt from FDA approval or notification. Read More

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Prognostic value of baseline metabolic tumor volume in children and adolescents with intermediate-risk Hodgkin lymphoma treated with chemo-radiation therapy: FDG-PET parameter analysis in a subgroup from COG AHOD0031.

Pediatr Blood Cancer 2021 Sep 10;68(9):e29212. Epub 2021 Jul 10.

Department of Radiology, University of Wisconsin School of Medicine and Public Health, Madison, Wisconsin, USA.

Background: Positron emission tomography (PET)-based measures of baseline total-body tumor burden may improve risk stratification in intermediate-risk Hodgkin lymphoma (HL).

Materials And Methods: Evaluable patients were identified from a cohort treated homogeneously with the same combined modality regimen on the Children's Oncology Group AHOD0031 study. Eligible patients had high-quality baseline PET scans. Read More

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September 2021

Brain Structural Signature of RFC1-Related Disorder.

Mov Disord 2021 Jul 9. Epub 2021 Jul 9.

Department of Neurology, School of Medical Sciences, University of Campinas (UNICAMP), Campinas, Brazil.

Background: The cerebellar ataxia, neuropathy, and vestibular areflexia syndrome was initially described in the early 1990s as a late-onset slowly progressive condition. Its underlying genetic cause was recently mapped to the RFC1 gene, and additional reports have expanded on the phenotypic manifestations related to RFC1, although little is known about the pattern and extent of structural brain abnormalities in this condition.

Objective: The aim is to characterize the structural signature of brain damage in RFC1-related disorder, correlating the findings with clinical symptoms and normal brain RFC1 expression. Read More

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Validation and Clinical Applicability of Whole-Volume Automated Segmentation of Optical Coherence Tomography in Retinal Disease Using Deep Learning.

JAMA Ophthalmol 2021 Jul 8. Epub 2021 Jul 8.

Google Health, London, United Kingdom.

Importance: Quantitative volumetric measures of retinal disease in optical coherence tomography (OCT) scans are infeasible to perform owing to the time required for manual grading. Expert-level deep learning systems for automatic OCT segmentation have recently been developed. However, the potential clinical applicability of these systems is largely unknown. Read More

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The International Workshop on Osteoarthritis Imaging Knee MRI Segmentation Challenge: A Multi-Institute Evaluation and Analysis Framework on a Standardized Dataset.

Radiol Artif Intell 2021 May 10;3(3):e200078. Epub 2021 Feb 10.

Departments of Radiology (A.D.D., G.E.G., B.A.H., A.S.C.) and Electrical Engineering (A.D.D., B.A.H.), Stanford University, Lucas Center for Imaging, 1201 Welch Rd, PS 055B, Stanford, CA 94305; Department of Radiology, University of California, San Francisco, San Francisco, Calif (F.C., C. Iriondo, V.P.); Berkeley Joint Graduate Group in Bioengineering, University of California, Berkeley, Berkeley, Calif (C. Iriondo); Department of Computer Science, University of Central Florida, Orlando, Fla (A.M., U.B.); Department of Radiology, Northwestern University, Chicago, Ill (U.B.); Department of Radiology, Columbia University, New York, NY (S.J.); Department of Computer Science, University of Copenhagen, Copenhagen, Denmark (M.P., C. Igel, E.B.D.); Department of Biomedical Engineering, Cleveland Clinic, Cleveland, Ohio (S.G., M.Y., X.L.); Department of Radiology, New York University Langone Health, New York, NY (C.M.D., R.R.); and Department of Biomedical Imaging and Image-guided Therapy, High-Field MR Centre, Medical University of Vienna, Vienna, Austria (V.J.).

Purpose: To organize a multi-institute knee MRI segmentation challenge for characterizing the semantic and clinical efficacy of automatic segmentation methods relevant for monitoring osteoarthritis progression.

Materials And Methods: A dataset partition consisting of three-dimensional knee MRI from 88 retrospective patients at two time points (baseline and 1-year follow-up) with ground truth articular (femoral, tibial, and patellar) cartilage and meniscus segmentations was standardized. Challenge submissions and a majority-vote ensemble were evaluated against ground truth segmentations using Dice score, average symmetric surface distance, volumetric overlap error, and coefficient of variation on a holdout test set. Read More

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Volumetric analysis of mucous retention cysts in the maxillary sinus: A retrospective study using cone-beam computed tomography.

Imaging Sci Dent 2021 Jun 29;51(2):117-127. Epub 2021 Jan 29.

Oral and Maxillofacial Radiology, Applied Oral Sciences and Community Dental Care, Faculty of Dentistry, The University of Hong Kong, Hong Kong SAR, China.

Purpose: The aim of this study was to evaluate the volumetric characteristics of mucous retention cysts (MRCs) in the maxillary sinus and to analyze potential associations of MRCs with dentoalveolar pathologies.

Materials And Methods: Cone-beam computed tomography (CBCT) scans exhibiting bilateral maxillary sinuses that were acquired from January 2016 to February 2019 were initially screened. A total of 227 scans (454 sinuses) that fulfilled the inclusion criteria were included. Read More

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Convex hull estimation of mammalian body segment parameters.

R Soc Open Sci 2021 Jun 30;8(6):210836. Epub 2021 Jun 30.

School of Biological Sciences, University of Reading, Reading RG6 6BX, UK.

Obtaining accurate values for body segment parameters (BSPs) is fundamental in many biomechanical studies, particularly for gait analysis. Convex hulling, where the smallest-possible convex object that surrounds a set of points is calculated, has been suggested as an effective and time-efficient method to estimate these parameters in extinct animals, where soft tissues are rarely preserved. We investigated the effectiveness of convex hull BSP estimation in a range of extant mammals, to inform the potential future usage of this technique with extinct taxa. Read More

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Prediction of incident vertebral fractures in routine MDCT: Comparison of global texture features, 3D finite element parameters and volumetric BMD.

Eur J Radiol 2021 Aug 24;141:109827. Epub 2021 Jun 24.

Pillar of Engineering Product Development, Singapore University of Technology and Design, 8 Somapah Road, Singapore 487372, Singapore; Changi General Hospital, 2 Simei Street 3, Singapore 529889, Singapore. Electronic address:

Purpose: In this case-control study, we evaluated different quantitative parameters derived from routine multi-detector computed tomography (MDCT) scans with respect to their ability to predict incident osteoporotic vertebral fractures of the thoracolumbar spine.

Methods: 16 patients who received baseline and follow-up contrast-enhanced MDCT and were diagnosed with an incident osteoporotic vertebral fracture at follow-up, and 16 age-, sex-, and follow-up-time-matched controls were included in the study. Vertebrae were labelled and segmented using a fully automated pipeline. Read More

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Automated cardiac volume assessment and cardiac long- and short-axis imaging plane prediction from electrocardiogram-gated computed tomography volumes enabled by deep learning.

Eur Heart J Digit Health 2021 Jun 22;2(2):311-322. Epub 2021 Mar 22.

Department of Bioengineering, UC San Diego School of Engineering, 9500 Gilman Drive, MC 0412, La Jolla, CA 92093, USA.

Aims: To develop an automated method for bloodpool segmentation and imaging plane re-slicing of cardiac computed tomography (CT) via deep learning (DL) for clinical use in coronary artery disease (CAD) wall motion assessment and reproducible longitudinal imaging.

Methods And Results: One hundred patients who underwent clinically indicated cardiac CT scans with manually segmented left ventricle (LV) and left atrial (LA) chambers were used for training. For each patient, long-axis (LAX) and short-axis planes were manually defined by an imaging expert. Read More

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Approximate image synthesis in optical coherence tomography.

Biomed Opt Express 2021 Jun 12;12(6):3323-3337. Epub 2021 May 12.

Department of Medical Physics and Biomedical Engineering, University College London, Gower Street, London WC1E 6BT, UK.

Full-wave models of OCT image formation, which are based on Maxwell's equations, are highly realistic. However, such models incur a high computational cost, particularly when modelling sample volumes consistent with those encountered in practice. Here, we present an approximate means of synthesizing volumetric image formation to reduce this computational burden. Read More

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Subcortical brain segment volumes in Gulf War Illness and Myalgic Encephalomyelitis/Chronic Fatigue Syndrome.

Life Sci 2021 Jun 29;282:119749. Epub 2021 Jun 29.

Pain Fatigue Research Alliance, Georgetown University, Washington, DC 20007-2197, USA. Electronic address:

Aims: There is controversy about brain volumes in Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (CFS) and Gulf War Illness (GWI). Subcortical regions were assessed because of significant differences in blood oxygenation level dependent signals in the midbrain between these diseases.

Materials And Method: Magnetization-prepared rapid acquisition with gradient echo (MPRAGE) images from 3 Tesla structural magnetic resonance imaging scans from sedentary control (n = 34), CFS (n = 38) and GWI (n = 90) subjects were segmented in FreeSurfer. Read More

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The Impact of an Ultra-Early Postoperative MRI on Treatment of Lower Grade Glioma.

Cancers (Basel) 2021 Jun 10;13(12). Epub 2021 Jun 10.

Department of Neurosurgery, University of Ulm, 89312 Günzburg, Germany.

The timing of MRI imaging after surgical resection may have an important role in assessing the extent of resection (EoR) and in determining further treatment. The aim of our study was to evaluate the time dependency of T2 and FLAIR changes after surgery for LGG. The Log-Glio database of patients treated at our hospital from 2016 to 2021 was searched for patients >18a and non-enhancing intra-axial lesion with complete MR-imaging protocol. Read More

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Interfractional Geometric Variations and Dosimetric Benefits of Stereotactic MRI Guided Online Adaptive Radiotherapy (SMART) of Prostate Bed after Radical Prostatectomy: Post-Hoc Analysis of a Phase II Trial.

Cancers (Basel) 2021 Jun 4;13(11). Epub 2021 Jun 4.

Department of Radiation Oncology, University of California, Los Angeles (UCLA), Los Angeles, CA 90095, USA.

Purpose: To evaluate geometric variations of patients receiving stereotactic body radiotherapy (SBRT) after radical prostatectomy and the dosimetric benefits of stereotactic MRI guided adaptive radiotherapy (SMART) to compensate for these variations.

Materials/methods: The CTV and OAR were contoured on 55 MRI setup scans of 11 patients treated with an MR-LINAC and enrolled in a phase II trial of post-prostatectomy SBRT. All patients followed institutional bladder and rectum preparation protocols and received five fractions of 6-6. Read More

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