title: Association of Radiomics and Metabolic Tumor Volumes in Radiation Treatment of Glioblastoma Multiforme.
abstract: To build a framework for investigation of the associations between imaging, clinical target volumes (CTVs), and metabolic tumor volumes (MTVs) features for better understanding of the underlying information in the CTVs and dependencies between these volumes. High-throughput extraction of imaging and metabolomic quantitative features from magnetic resonance imaging (MRI) and magnetic resonance spectroscopic imaging of glioblastoma multiforme (GBM) results in tens of variables per patient. In radiation therapy of GBM the relevant metabolic tumor volumes (MTVs) are related to aberrant levels of N-acetyl aspartate (NAA) and choline (Cho). The corresponding clinical target volumes (CTVs) for radiation therapy are based on contrast-enhanced T1-weighted (CE-T1w) and T2-weighted (T2w)/fluid-attenuated inversion recovery MRI.
  
  
  
  Necrotic portions, enhancing lesion, and edema were manually contoured on CE-T1w/T2w images for 17 GBM patients. Clinical target volumes and MTVs for NAA (MTVNAA) and Cho (MTVCho) were constructed. Imaging and metabolic features related to size, shape, and signal intensities of the volumes were extracted. Tumors were also scored categorically for 10 semantic imaging traits by a neuroradiologist. All features were investigated for redundancy. Two-way correlations between imaging and CTVs/MTVs features were visualized as heatmaps. Associations between MTVNAAand MTVChoand imaging features were studied using Spearman correlation.
  
  
  
  Forty-eight imaging features were extracted per patient. Half of the imaging traits were replaced with automatically extracted continuous variables. Twenty features were extracted from CTVs and MTVs. A series of semantic imaging traits were replaced with automatically extracted continuous variables. There were multiple (22) significant correlations of imaging measures with CTVs/MTVNAA, whereas there were only 6 with CTVs/MTVCho.
  
  
  
  A framework for investigation of codependencies between MRI and magnetic resonance spectroscopic imaging radiomic features and CTVs/MTVs has been established. The MTV for NAA was found to be closely associated with MRI volumes, whereas very few imaging features were related to MTVCho, indicating that Cho provides additional information to imaging.
authors.affiliation: Department of Radiation Oncology, Sylvester Comprehensive Cancer Center, University of Miami Miller School of Medicine, Miami, Florida.
authors.forename: Christopher J
authors.initials: CJ
authors.lastname: Lopez
authors.affiliation: Department of Radiology, Sylvester Comprehensive Cancer Center, University of Miami Miller School of Medicine, Miami, Florida.
authors.forename: Natalya
authors.initials: N
authors.lastname: Nagornaya
authors.affiliation: Department of Radiation Oncology, Sylvester Comprehensive Cancer Center, University of Miami Miller School of Medicine, Miami, Florida.
authors.forename: Nestor A
authors.initials: NA
authors.lastname: Parra
authors.affiliation: Biostatistics and Bioinformatics Core Resource, Sylvester Comprehensive Cancer Center, University of Miami Miller School of Medicine, Miami, Florida.
authors.forename: Deukwoo
authors.initials: D
authors.lastname: Kwon
authors.affiliation: Department of Radiation Oncology, Sylvester Comprehensive Cancer Center, University of Miami Miller School of Medicine, Miami, Florida.
authors.forename: Fazilat
authors.initials: F
authors.lastname: Ishkanian
authors.affiliation: Department of Radiation Oncology, Sylvester Comprehensive Cancer Center, University of Miami Miller School of Medicine, Miami, Florida.
authors.forename: Arnold M
authors.initials: AM
authors.lastname: Markoe
authors.affiliation: Department of Radiology, Sylvester Comprehensive Cancer Center, University of Miami Miller School of Medicine, Miami, Florida.
authors.forename: Andrew
authors.initials: A
authors.lastname: Maudsley
authors.affiliation: Department of Radiation Oncology, Sylvester Comprehensive Cancer Center, University of Miami Miller School of Medicine, Miami, Florida. Electronic address: RStoyanova@med.miami.edu.
authors.forename: Radka
authors.initials: R
authors.lastname: Stoyanova
mesh_terms: D001224:Aspartic Acid / Q000031:analogs & derivatives / Q000378:metabolism; D001932:Brain Neoplasms / Q000000981:diagnostic imaging / Q000378:metabolism* / Q000473:pathology / Q000532:radiotherapy; D002794:Choline / Q000378:metabolism; D005909:Glioblastoma / Q000000981:diagnostic imaging / Q000378:metabolism* / Q000473:pathology / Q000532:radiotherapy*; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods; D009682:Magnetic Resonance Spectroscopy / Q000379:methods; D055432:Metabolomics; D009336:Necrosis / Q000378:metabolism; D047368:Tumor Burden
chemical_list: D001224:Aspartic Acid; C000179:N-acetylaspartate; D002794:Choline