Year: 2018
Type: conference-abstract
Abstract: The goal of this project is to identify serial advanced imaging markers that can reveal tumor progression in grade II and III gliomas prior to the to the onset of new contrast enhancement or the expansion of FLAIR abnormality. Nineteen lower grade glioma patients were identified with tumor progression during their participation in research on serial advanced MR imaging and spectroscopy at standard of care timepoints (2–6 months). The average number of scans acquired prior to progression was 7 (range = 12–3). The 3T MRI examination included T1-weighted IRSPGR, T2-weighted FSE, T2 FLAIR, and 6 directional diffusion weighted imaging. Maps of the apparent diffusion coefficient (ADC) and fractional anisotropy (FA) were calculated, and percentiles (10th, 50th, 90th) from histograms of normalized intensities. Serial images were aligned to the baseline image. Regions of Interest (ROIs) were defined for the entire T2 FLAIR lesion, and when present, the contrast-enhancing (CE) T1 lesion at each timepoint. In addition, we created a Progression ROI consisting of the region that was normal on the baseline T2 FLAIR but abnormal at the time of clinical progression, and a Baseline ROI consisting of the region that was abnormal at baseline and progression. Serial imaging parameters were acquired for each of these ROIs at every timepoint. We determined the imaging parameters with significant changes within the ROIs leading up to the time of progression using repeated-measures analyses of variance. Leading up to the time of progression, there were significant declines in median and 10% normalized ADC and 10% normalized FA within the Baseline T2 FLAIR abnormality ROI. Median normalized ADC also declined significantly in the Progression ROI, indicating changes in diffusion parameters prior to the onset of T2 FLAIR abnormality and the clinical determination of progression.
Source: Neuro-Oncology
Institution: University of California, San Francisco
Language: English
Subfield: Genetics (clinical)
Field: Medicine
Domain: Health Sciences
Open Access status: bronze
OpenAlex ID: W2899525192