Wavelet-Based Radiomics Analysis of Dynamic Contrast-Enhanced (DCE)-MR Information for Characterization of Acute Brain Tumor Response in Animal Model
Recommended Citation
Bagher-Ebadian H, Nagaraja T, Cabral G, Farmer KG, Valadie OG, Acharya P, Movsas B, Brown SL, Ewing J, Chetty I. Wavelet-Based Radiomics Analysis of Dynamic Contrast-Enhanced (DCE)-MR Information for Characterization of Acute Brain Tumor Response in Animal Model. Med Phys 2022; 49(6):e289-e290.
Document Type
Conference Proceeding
Publication Date
7-11-2022
Publication Title
Med Phys
Keywords
gadolinium pentetate, adult, animal experiment, animal model, brain region, brain tumor, cancer cell, cancer patient, cancer transplantation, conference abstract, controlled study, disease simulation, dynamic contrast-enhanced magnetic resonance imaging, glioma, male, nonhuman, nuclear magnetic resonance imaging, pharmacokinetics, radiation exposure, radiomics, radiotherapy, rat, Rowett nude rat, tail vein, treatment planning, U-251MG cell line, vascularization
Abstract
Purpose: Recent studies have shown that tumor heterogeneity plays a key role in response to treatment and can hinder the treatment efficacy. Decoding heterogeneity information of tumors and regional characterization of their radiation therapy (RT) response remains a major challenge. This study combines a physiological nested model selection (MS) technique with a novel wavelet-based spatiotemporal modeling of DCE-MRI information, enabling evaluation of the RT-affected regions in an animal model of cerebral U-251n tumors. Methods: Twenty-three immunecompromised- RNU rats were implanted with human U251n cancer cells to form an orthotopic glioma (IACUC #1509). For each rat, 28 days after tumor implantation, two DCE-MRI studies (7T-Dual-Gradient-Echo, FOV:32x32mm2, TR/(TE1-TE2)=24ms/(2ms-4ms), flip-angle=18, 400-acquisitions/1.55sec-interval, Magnevist/tail-vein) were performed 24h apart. A single 20Gy stereotactic-radiation exposure was performed before the second MRI (acquired 1-6.5 hours post-RT). DCE-MRI analysis was done using a model-selection technique to distinguish three brain regions: Normal vasculature (Model-1: No-leakage), leaky tumor tissues with no back-flux to vasculature (Model-2), and leaky tumor tissues with back-flux (Model-3). Normalized time-traces of DCE-MRI information (1st and 2nd echoes for pre, and post-RT cohorts) for three model regions were analyzed using a wavelet-based radiomics technique to characterize their time-frequency information before and after RT. For each model, the pre- and post-RT signal coherence level was estimated and compared to rank the effect of RT on different model regions and time-varying DCE-MRI raw data. Results: Compared to the peritumoral tissues (Model-2 region with r=0.622, p<0.0001), the DCE-MRI information of rat brain in normal and highly permeable tissues (Models-1 and 3: r=0.650 with p<0.0001 and r=0.809 with p<0.0001, respectively) are less impacted by RT. Conclusion: This study demonstrates an important step toward spatiotemporal characterization of RT-affected brain regions and the time-varying DCE-MR information, which can play a key role in treatment planning of cancer patients, optimization of imaging, and DCE-MRI pharmacokinetic analysis.
Volume
49
Issue
6
First Page
e289
Last Page
e290
