title: Correlation of18F-FDG PET and MRI Apparent Diffusion Coefficient Histogram Metrics with Survival in Diffuse Intrinsic Pontine Glioma: A Report from the Pediatric Brain Tumor Consortium.
abstract: The purpose of this study was to describe baseline18F-FDG PET voxel characteristics in pediatric diffuse intrinsic pontine glioma (DIPG) and to correlate these metrics with baseline MRI apparent diffusion coefficient (ADC) histogram metrics, progression-free survival (PFS), and overall survival.Methods:Baseline brain18F-FDG PET and MRI scans were obtained in 33 children from Pediatric Brain Tumor Consortium clinical DIPG trials.18F-FDG PET images, postgadolinium MR images, and ADC MR images were registered to baseline fluid attenuation inversion recovery MR images. Three-dimensional regions of interest on fluid attenuation inversion recovery MR images and postgadolinium MR images and18F-FDG PET and MR ADC histograms were generated. Metrics evaluated included peak number, skewness, and kurtosis. Correlation between PET and MR ADC histogram metrics was evaluated. PET pixel values within the region of interest for each tumor were plotted against MR ADC values. The association of these imaging markers with survival was described.Results:PET histograms were almost always unimodal (94%, vs. 6% bimodal). None of the PET histogram parameters (skewness or kurtosis) had a significant association with PFS, although a higher PET postgadolinium skewness tended toward a less favorable PFS (hazard ratio, 3.48; 95% confidence interval [CI], 0.75-16.28 [P= 0.11]). There was a significant association between higher MR ADC postgadolinium skewness and shorter PFS (hazard ratio, 2.56; 95% CI, 1.11-5.91 [P= 0.028]), and there was the suggestion that this also led to shorter overall survival (hazard ratio, 2.18; 95% CI, 0.95-5.04 [P= 0.067]). Higher MR ADC postgadolinium kurtosis tended toward shorter PFS (hazard ratio, 1.30; 95% CI, 0.98-1.74 [P= 0.073]). PET and MR ADC pixel values were negatively correlated using the Pearson correlation coefficient. Further, the level of PET and MR ADC correlation was significantly positively associated with PFS; tumors with higher values of ADC-PET correlation had more favorable PFS (hazard ratio, 0.17; 95% CI, 0.03-0.89 [P= 0.036]), suggesting that a higher level of negative ADC-PET correlation leads to less favorable PFS. A more significant negative correlation may indicate higher-grade elements within the tumor leading to poorer outcomes.Conclusion:18F-FDG PET and MR ADC histogram metrics in pediatric DIPG demonstrate different characteristics with often a negative correlation between PET and MR ADC pixel values. A higher negative correlation is associated with a worse PFS, which may indicate higher-grade elements within the tumor.
authors.affiliation: McMaster University, Hamilton, Ontario, Canada.
authors.forename: Katherine A
authors.initials: KA
authors.lastname: Zukotynski
authors.affiliation: Boston Children's Hospital, Boston, Massachusetts.|Harvard Medical School, Boston, Massachusetts.
authors.forename: Sridhar
authors.initials: S
authors.lastname: Vajapeyam
authors.affiliation: Boston Children's Hospital, Boston, Massachusetts.|Harvard Medical School, Boston, Massachusetts.
authors.forename: Frederic H
authors.initials: FH
authors.lastname: Fahey
authors.affiliation: University of Tennessee Health Science Center, Memphis, Tennessee.|St. Jude Children's Research Hospital, Memphis, Tennessee.
authors.forename: Mehmet
authors.initials: M
authors.lastname: Kocak
authors.affiliation: Boston Children's Hospital, Boston, Massachusetts.
authors.forename: Douglas
authors.initials: D
authors.lastname: Brown
authors.affiliation: Massachusetts General Hospital, Boston, Massachusetts; and.
authors.forename: Kelsey I
authors.initials: KI
authors.lastname: Ricci
authors.affiliation: St. Jude Children's Research Hospital, Memphis, Tennessee.
authors.forename: Arzu
authors.initials: A
authors.lastname: Onar-Thomas
authors.affiliation: Cincinnati Children's Hospital, Cincinnati, Ohio.
authors.forename: Maryam
authors.initials: M
authors.lastname: Fouladi
authors.affiliation: Boston Children's Hospital, Boston, Massachusetts tina.poussaint@childrens.harvard.edu.|Harvard Medical School, Boston, Massachusetts.
authors.forename: Tina Young
authors.initials: TY
authors.lastname: Poussaint
mesh_terms: D000293:Adolescent; D020295:Brain Stem Neoplasms / Q000000981:diagnostic imaging* / Q000378:metabolism; D002648:Child; D002675:Child, Preschool; D004058:Diffusion; D018572:Disease-Free Survival; D005260:Female; D019788:Fluorodeoxyglucose F18; D005910:Glioma / Q000000981:diagnostic imaging* / Q000378:metabolism; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D049268:Positron-Emission Tomography; D012189:Retrospective Studies; D055815:Young Adult
chemical_list: D019788:Fluorodeoxyglucose F18
keywords: FDG PET histogram; brain tumor; diffuse intrinsic pontine glioma; pediatric ADC histogram