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  • Gurbani, Saumya  (6)
  • 2015-2019  (6)
  • 1
    In: Tomography, MDPI AG, Vol. 5, No. 1 ( 2019-03-01), p. 184-191
    Abstract: Glioblastoma has poor prognosis with inevitable local recurrence despite aggressive treatment with surgery and chemoradiation. Radiation therapy (RT) is typically guided by contrast-enhanced T1-weighted magnetic resonance imaging (MRI) for defining the high-dose target and T2-weighted fluid-attenuation inversion recovery MRI for defining the moderate-dose target. There is an urgent need for improved imaging methods to better delineate tumors for focal RT. Spectroscopic MRI (sMRI) is a quantitative imaging technique that enables whole-brain analysis of endogenous metabolite levels, such as the ratio of choline-to-N-acetylaspartate. Previous work has shown that choline-to-N-acetylaspartate ratio accurately identifies tissue with high tumor burden beyond what is seen on standard imaging and can predict regions of metabolic abnormality that are at high risk for recurrence. To facilitate efficient clinical implementation of sMRI for RT planning, we developed the Brain Imaging Collaboration Suite (BrICS; https://brainimaging.emory.edu/brics-demo), a cloud platform that integrates sMRI with standard imaging and enables team members from multiple departments and institutions to work together in delineating RT targets. BrICS is being used in a multisite pilot study to assess feasibility and safety of dose-escalated RT based on metabolic abnormalities in patients with glioblastoma (Clinicaltrials.gov NCT03137888). The workflow of analyzing sMRI volumes and preparing RT plans is described. The pipeline achieved rapid turnaround time by enabling team members to perform their delegated tasks independently in BrICS when their clinical schedules allowed. To date, 18 patients have been treated using targets created in BrICS and no severe toxicities have been observed.
    Type of Medium: Online Resource
    ISSN: 2379-139X
    Language: English
    Publisher: MDPI AG
    Publication Date: 2019
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  • 2
    Online Resource
    Online Resource
    Oxford University Press (OUP) ; 2019
    In:  Neuro-Oncology Vol. 21, No. Supplement_6 ( 2019-11-11), p. vi166-vi166
    In: Neuro-Oncology, Oxford University Press (OUP), Vol. 21, No. Supplement_6 ( 2019-11-11), p. vi166-vi166
    Abstract: Glioblastoma is the most aggressive primary adult brain tumor, with median survival of 15 months despite surgery and chemoradiation. MRI is used to guide treatment decisions, but imaging interpretation is challenging because of subtle findings with overlap between treatment effect and disease progression. The most frequently used quantitative brain tumor assessment metric is the Response Assessment in Neuro-Oncology (RANO), but this scoring system requires manual delineation 2-D metrics which can be subjective and is not directly tied to patient management decisions. The Brain Tumor Reporting and Data System (BT-RADS) is a novel, management-based reporting system developed by the Emory brain tumor team to improve quantitation and reduce bias in imaging assessment. BT-RADS scoring incorporates quantitative volumetric changes in contrast-enhanced T1-weighted (CE-T1w) and fluid attenuation inversion recovery (FLAIR) MRI, patient medications, clinical outcome, and treatment dates, and has been aligned closely with management decisions. To improve repeatability and reliability of scoring, we have begun to develop a cloud platform to help physicians utilizing BT-RADS. Longitudinal MRI data from each patient are automatically co-registered using rigid registration and aligned using trilinear interpolation, enabling voxel-to-voxel comparisons across multiple scans. The platform implements a semi-automated algorithm to segment tumor volumes using curvature flow, thresholding, and morphological filtering which expedites clinical review, as physicians simply edit and confirm segmentation accuracy rather than manual segmenting and measuring 2D images. Additionally, radiation dose maps can be overlaid on clinical images to determine what may be treatment effect and in-field vs. out-of-field recurrence. A secure web interface allows easy use by the entire treatment team, e.g. in a “tumor board” setting. Future plans include incorporating clinical and genomic data and fully automating tumor segmentation. The goal of this work is to provide more quantitative and objective follow-up metrics that can guide clinical decision making in glioblastoma patients.
    Type of Medium: Online Resource
    ISSN: 1522-8517 , 1523-5866
    Language: English
    Publisher: Oxford University Press (OUP)
    Publication Date: 2019
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  • 3
    In: Neuro-Oncology, Oxford University Press (OUP), Vol. 20, No. suppl_6 ( 2018-11-05), p. vi231-vi231
    Type of Medium: Online Resource
    ISSN: 1522-8517 , 1523-5866
    Language: English
    Publisher: Oxford University Press (OUP)
    Publication Date: 2018
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  • 4
    In: Tomography, MDPI AG, Vol. 2, No. 4 ( 2016-12-01), p. 366-373
    Abstract: Due to glioblastoma's infiltrative nature, an optimal radiation therapy (RT) plan requires targeting infiltration not identified by anatomical magnetic resonance imaging (MRI). Here, high-resolution, whole-brain spectroscopic MRI (sMRI) is used to describe tumor infiltration alongside anatomical MRI and simulate the degree to which it modifies RT target planning. In 11 patients with glioblastoma, data from preRT sMRI scans were processed to give high-resolution, whole-brain metabolite maps normalized by contralateral white matter. Maps depicting choline to N-Acetylaspartate (Cho/NAA) ratios were registered to contrast-enhanced T1-weighted RT planning MRI for each patient. Volumes depicting metabolic abnormalities (1.5-, 1.75-, and 2.0-fold increases in Cho/NAA ratios) were compared with conventional target volumes and contrast-enhancing tumor at recurrence. sMRI-modified RT plans were generated to evaluate target volume coverage and organ-at-risk dose constraints. Conventional clinical target volumes and Cho/NAA abnormalities identified significantly different regions of microscopic infiltration with substantial Cho/NAA abnormalities falling outside of the conventional 60 Gy isodose line (41.1, 22.2, and 12.7 cm3, respectively). Clinical target volumes using Cho/NAA thresholds exhibited significantly higher coverage of contrast enhancement at recurrence on average (92.4%, 90.5%, and 88.6%, respectively) than conventional plans (82.5%). sMRI-based plans targeting tumor infiltration met planning objectives in all cases with no significant change in target coverage. In 2 cases, the sMRI-modified plan exhibited better coverage of contrast-enhancing tumor at recurrence than the original plan. Integration of the high-resolution, whole-brain sMRI into RT planning is feasible, resulting in RT target volumes that can effectively target tumor infiltration while adhering to conventional constraints.
    Type of Medium: Online Resource
    ISSN: 2379-139X
    Language: English
    Publisher: MDPI AG
    Publication Date: 2016
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  • 5
    Online Resource
    Online Resource
    Oxford University Press (OUP) ; 2019
    In:  Neuro-Oncology Vol. 21, No. Supplement_6 ( 2019-11-11), p. vi246-vi246
    In: Neuro-Oncology, Oxford University Press (OUP), Vol. 21, No. Supplement_6 ( 2019-11-11), p. vi246-vi246
    Abstract: Primary brain tumors are serious and life-threatening; thus, accurate histopathologic diagnosis is critical for determining the proper clinical treatment regimen. Grade II/III gliomas (lower grade gliomas, or LGGs), including astrocytomas and oligodendrogliomas, are heterogeneous and potentially contain low- and high-grade areas within the same tumor. Therefore, it is critical to target biopsies to the most aggressive portion of the tumor to avoid tumor under-grading and under-treatment. While glioblastomas are typically targeted based on contrast-enhanced MRI, LGGs have little contrast enhancement to define targets for biopsy treatment guidance. Spectroscopic MRI (sMRI) is a high-resolution MRI imaging method which allows for detection of metabolic abnormalities such as choline and NAA in the entire brain without injection of a contrast agent. We have previously evaluated the relationship between sMRI Cho/NAA ratios and tumor infiltration in surgical specimens from high grade gliomas, demonstrating a strong correlation between sMRI results and glioma infiltration. We also used the location information to correlate sMRI data to genetic and histologic biomarkers (such as 1p19q, IDH, and MGMT). An IRB-approved pilot study to obtain sMRI prior to stereotactic biopsy has been done in 20 non-enhancing LGG cases. Patients with a suspected LGG diagnosis underwent sMRI at the time of their surgical planning MRI. sMRI images were then registered to the T1w-CE and T2/FLAIR images and imported into the Stealth neuronavigation system for biopsy planning. We found that all astrocytomas (regardless of grades) showed strongly elevated Cho/NAA, while the LGGs were hardly delineated on T1w and T2/FLAIR. We found that pathology-confirmed grade II oligodendroglioma do not have choline elevation; however, NAA was mildly decreased, myo-inositol was elevated, and creatine (Cr) was mildly elevated. sMRI is a useful tool to improve biopsy targeting in LGG patients by ensuring that the highest risk regions are sampled.
    Type of Medium: Online Resource
    ISSN: 1522-8517 , 1523-5866
    Language: English
    Publisher: Oxford University Press (OUP)
    Publication Date: 2019
    detail.hit.zdb_id: 2094060-9
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  • 6
    In: Neuro-Oncology, Oxford University Press (OUP), Vol. 21, No. Supplement_6 ( 2019-11-11), p. vi29-vi30
    Abstract: The standard of care for glioblastoma is neurosurgical resection followed by radiation therapy (RT) and temozolomide (TMZ) chemotherapy. Although RT is effective for glioblastoma, attempts to improve survival using RT dose escalation above 60 Gy have been largely unsuccessful. This may be because prior attempts have been targeted to resection cavity or enhancing tumor, which may not accurately predict areas at highest recurrence risk. To overcome the limitations of standard T1 and T2-weighted MRI in predicting tumor recurrence, we have shown that supplementation with 3D high-resolution spectroscopic MRI (sMRI) identifies actively proliferating tumor beyond areas of T1-enhancement by measuring endogenous metabolites and their ratios. Previously, we demonstrated that the choline to N-acetylaspartate ratio (Cho/NAA) best correlates with tumor cellularity in surgically resected tissue (ρ=0.82, p 〈 0.001) and, most importantly, areas of sMRI metabolic abnormalities predate disease recurrence in those same areas (Cordova et al, Neuro-Oncology 2016). Therefore, we seek to identify whether sMRI can be used by radiation oncologists to choose the optimal regions to target for RT dose escalation. To assess its feasibility and safety, we developed a web-based imaging platform designed specifically to incorporate sMRI into the RT planning clinical workflow and are using it in a multisite sMRI-guided dose escalation trial (NCT03137888; Emory, Johns Hopkins, U. Miami). Recently, we have completed full enrollment including 30 patients treated with sMRI-guided dose escalated RT across three institutions. We have demonstrated successful integration of sMRI into the RT planning workflow, and we have delivered sMRI-guided dose escalated RT plans to glioblastoma patients without severe adverse events to date. Follow-up data will be analyzed for overall and progression-free survival. Based on the feasibility and safety of this technique in the current trial, we plan to assess the efficacy of sMRI-guided dose-escalated RT on patient outcomes in a NCTN clinical trial.
    Type of Medium: Online Resource
    ISSN: 1522-8517 , 1523-5866
    Language: English
    Publisher: Oxford University Press (OUP)
    Publication Date: 2019
    detail.hit.zdb_id: 2094060-9
    Location Call Number Limitation Availability
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