Multiparametric Analysis of Permeability and ADC Histogram Metrics for Classification of Pediatric Brain Tumors by Tumor Grade

S Vajapeyam; D Brown; P R Johnston; K I Ricci; M W Kieran; H G W Lidov; T Y Poussaint

doi:10.3174/ajnr.A5502

Multiparametric Analysis of Permeability and ADC Histogram Metrics for Classification of Pediatric Brain Tumors by Tumor Grade

AJNR Am J Neuroradiol. 2018 Mar;39(3):552-557. doi: 10.3174/ajnr.A5502. Epub 2018 Jan 4.

Authors

S Vajapeyam^{1

2}, D Brown³, P R Johnston³, K I Ricci⁴, M W Kieran^{5

2}, H G W Lidov^{6

2}, T Y Poussaint^{3

2}

Affiliations

¹ From the Departments of Radiology (S.V., D.B., P.R.J., T.Y.P.) sridhar.vajapeyam@childrens.harvard.edu.
² Harvard Medical School (S.V., M.W.K., H.G.W.L., T.Y.P.), Boston, Massachusetts.
³ From the Departments of Radiology (S.V., D.B., P.R.J., T.Y.P.).
⁴ Cancer Center (K.I.R.), Massachusetts General Hospital, Boston, Massachusetts.
⁵ Division of Pediatric Oncology (M.W.K.), Dana-Farber Boston Children's Cancer and Blood Disorders Center, Boston, Massachusetts.
⁶ Pathology (H.G.W.L.), Boston Children's Hospital, Boston, Massachusetts.

Abstract

Background and purpose: Accurate tumor grading is essential for treatment planning of pediatric brain tumors. We hypothesized that multiparametric analyses of a combination of permeability metrics and ADC histogram metrics would differentiate high- and low-grade tumors with high accuracy.

Materials and methods: DTI and dynamic contrast-enhanced MR imaging using T1-mapping with flip angles of 2°, 5°, 10°, and 15°, followed by a 0.1-mmol/kg body weight gadolinium-based bolus was performed on all patients in addition to standard MR imaging. Permeability data were processed and transfer constant from the blood plasma into the extracellular extravascular space, rate constant from the extracellular extravascular space back into blood plasma, extravascular extracellular volume fraction, and fractional blood plasma volume were calculated from 3D tumor volumes. Apparent diffusion coefficient histogram metrics were calculated for 3 separate tumor volumes derived from T2-FLAIR sequences, T1 contrast-enhanced sequences, and permeability maps, respectively.

Results: Results from 41 patients (0.3-16.76 years of age; mean, 6.22 years) with newly diagnosed contrast-enhancing brain tumors (16 low-grade; 25 high-grade) were included in the institutional review board-approved retrospective analysis. Wilcoxon tests showed a higher transfer constant from blood plasma into extracellular extravascular space and rate constant from extracellular extravascular space back into blood plasma, and lower extracellular extravascular volume fraction (P < .001) in high-grade tumors. The mean ADCs of FLAIR and enhancing tumor volumes were significantly lower in high-grade tumors (P < .001). ROC analysis showed that a combination of extravascular volume fraction and mean ADC of FLAIR volume differentiated high- and low-grade tumors with high accuracy (area under receiver operating characteristic curve = 0.918).

Conclusions: ADC histogram metrics combined with permeability metrics differentiate low- and high-grade pediatric brain tumors with high accuracy.

MeSH terms

Adolescent
Brain Neoplasms / classification
Brain Neoplasms / diagnostic imaging*
Brain Neoplasms / pathology*
Child
Child, Preschool
Female
Humans
Infant
Magnetic Resonance Imaging / methods*
Male
Neoplasm Grading / methods*
Permeability
ROC Curve
Retrospective Studies