The Neuroimaging Center of the Pediatric Brain Tumor Consortium–Collaborative Neuroimaging in Pediatric Brain Tumor Research: A Work in Progress
ABSTRACT As an essential part of the National Cancer Institute (NCI)-funded Pediatric Brain Tumor Consortium (PBTC), the Neuroimaging Center (NIC) is dedicated to infusing the study of pediatric brain tumors with imaging "best practice" by producing a correlative research plan that 1) resonates with novel therapeutic interventions being developed by the wider PBTC, 2) ensures that every PBTC protocol incorporates an imaging "end point" among its objectives, 3) promotes the widespread implementation of standardized technical protocols for neuroimaging, and 4) facilitates a quality assurance program that complies with the highest standards for image data transfer, diagnostic image quality, and data integrity. To accomplish these specific objectives, the NIC works with the various PBTC sites (10 in all, plus NCI/ National Institute of Neurological Diseases and Stroke representation) to ensure that the overarching mission of the consortium--to better understand tumor biology and develop new therapies for central nervous system tumors in children--is furthered by creating a uniform body of imaging techniques, technical protocols, and standards. Since the inception of the NIC in 2003, this broader mandate has been largely accomplished through a series of site visits and meetings aimed at assessing prevailing neuroimaging practices against NIC-recommended protocols, techniques, and strategies for achieving superior image quality and executing the secure transfer of data to the central PBTC. These ongoing evaluations periodically examine investigations into targeted drug therapies. In the future, the NIC will concentrate its efforts on improving image analysis for MR imaging and positron-emission tomography (PET) and on developing new ligands for PET; imaging markers for radiation therapy; and novel systemic, intrathecal, and intralesional therapeutic interventions.
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ABSTRACT: In this investigation, we compare two-dimensional (2D) fluid-attenuated inversion recovery (FLAIR) imaging of the brain to an isotropic three-dimensional (3D) FLAIR technique that uses a modulated refocusing flip angle echo train and parallel imaging with 2D acceleration. Two-dimensional and 3D FLAIR sequences were obtained in 16 patients. All examinations were performed on a 3 Tesla (T) magnetic resonance (MR) system. Flow artifacts within the subarachnoid space and ventricles were scored using a 4-point scale. For 2D and 3D FLAIR, the signal-to-noise ratios and contrast-to-noise ratios were calculated. Compared to 2D FLAIR, the 3D FLAIR images were less degraded by flow artifacts in the subarachnoid space and ventricle (P < 0.03) based on the qualitative imaging scores. Signal-to-noise ratios and contrast-to-noise ratios were higher for 3D FLAIR (P < 0.02) for all variables when compared with 2D FLAIR sequence. The acquisition time for whole brain isotropic fast spin echo 3D FLAIR can be dramatically reduced by using an extended echo train with flip angle modulation and parallel imaging. The adiabatic, nonselective inversion pulse encompasses the entire volume and provides uniform suppression of the cerebrospinal fluid signal eliminating cerebrospinal fluid pulsation artifacts. Other advantages include reformatting in any desired plane, volume measurements, displays of surface anatomy, and coregistration.Investigative radiology 08/2008; 43(8):547-51. DOI:10.1097/RLI.0b013e3181814d28 · 4.45 Impact Factor
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ABSTRACT: PurposeThe rationale of this study was to investigate the feasibility of three-dimensional (3D) methods to analyze 18F-fluoro-deoxy-glucose (FDG) uptake in children with anaplastic astrocytoma (AA) in a multi-institutional trial, to compare 3D and two-dimensional (2D) methods and explore data associations with progression-free survival (PFS). Methods3D tumor volumes from pretreatment MR images (fluid attenuation inversion recovery and postgadolinium) of children with recurrent AA on a phase I trial of imatinib mesylate were coregistered to FDG positron emission tomography (PET) images. PET data were normalized. Four metrics were defined: the maximum ratio (maximum pixel value within the 3D tumor volume, normalized), the total ratio (cumulative pixel values within the tumor volume, normalized) and tumor mean ratio (total pixel value divided by volume, normalized). 2D analysis methods were compared. Cox proportional hazards models were used to estimate the association between these methods and PFS. ResultsStrongest correlations between 2D and 3D methods were with analyses using postcontrast T1 images for volume of interest (VOI). The analyses suggest 3D maximum tumor and mean tumor ratios, whether normalized by gray matter or white matter, were associated with PFS. ConclusionsThis study of a series of pretreatment AA patients suggests that 3D PET methods using VOIs based on postcontrast T1 correlate with 2D methods and are related to PFS. These methods yield an estimate of metabolically active tumor burden and may add prognostic information after tumor grade is determined. Future rigorous multi-institutional protocols with larger numbers of patients will be required for validation.European journal of nuclear medicine and molecular imaging 09/2008; 35(9):1651-1658. DOI:10.1007/s00259-008-0780-7 · 5.22 Impact Factor
- PET Clinics 10/2008; 3(4):517-529. DOI:10.1016/j.cpet.2009.03.005