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Dasgupta et al. J Transl Genet Genom 2018;2:15 Journal of Translational
DOI: 10.20517/jtgg.2018.21 Genetics and Genomics

Review Open Access

Radiogenomics of medulloblastoma: imaging
surrogates of molecular biology

Archya Dasgupta, Tejpal Gupta

Department of Radiation Oncology, ACTREC, Tata Memorial Centre, Navi Mumbai 410210, India.
Correspondence to: Dr. Tejpal Gupta, Department of Radiation Oncology, ACTREC, Tata Memorial Centre, Navi Mumbai 410210, India.
E-mail: tejpalgupta@rediffmail.com

How to cite this article: Dasgupta A, Gupta T. Radiogenomics of medulloblastoma: imaging surrogates of molecular biology. J Transl
Genet Genom 2018;2:15. https://doi.org/10.20517/jtgg.2018.21
Received: 7 Jul 2018 First Decision: 17 Jul 2018 Revised: 13 Sep 2018 Accepted: 17 Sep 2018 Published: 24 Oct 2018

Science Editor: David N. Cooper Copy Editor: Cui Yu Production Editor: Zhong-Yu Guo

Abstract

Medulloblastoma is a heterogeneous disease comprising four molecular subgroups - wingless (WNT), sonic hedge hog
(SHH), group 3, and group 4, with distinct developmental origins, unique transcriptional profiles, diverse phenotypes,
and varying clinical outcomes. Magnetic resonance imaging (MRI) is the preferred first-line imaging modality in the
diagnosis and staging of suspected brain tumors including medulloblastoma. It is being increasingly recognized that
imaging features reflect underlying disease biology that can serve as independent predictive and prognostic biomarkers.
Radiogenomics is an emerging field of research that aims to define relationships between non-invasive imaging features
(radio-phenotypes) and genomic data/molecular markers (molecular phenotypes). Recent studies have reported
encouraging data regarding imaging genomics of medulloblastoma with certain MRI features correlating with specific
molecular subgroups. These include lateralized cerebellar location for SHH-subgroup; cerebellopontine angle location
for WNT-subgroup; and inferior location with dilation of superior recess of the IVth ventricle for group 4 tumors. Minimal
enhancement of primary tumor and ependymal metastases (infundibular/suprasellar) with mismatching pattern is a
specific feature of group 4 medulloblastoma. A 5-metabolite signature profile on magnetic resonance spectroscopy
reliably differentiates SHH-subgroup from non-WNT/non-SHH medulloblastoma. SHH-specific binary nomogram
(location on horizontal and vertical axis, relationship with dorsal brainstem, pattern of contrast-enhancement, and
peri-tumoral edema as discriminating imaging features) is associated with excellent predictive accuracy, followed by
group 4-specific nomogram, with suboptimal accuracy of WNT and group 3-specific nomograms. The advent of deep
machine-learning techniques and convoluted artificial neural networks should provide unique opportunities to further
improve the accuracy of such radiogenomic correlation and prediction.

Keywords: Genomics, imaging, medulloblastoma, molecular subgrouping

© The Author(s) 2018. Open Access This article is licensed under a Creative Commons Attribution 4.0
International License (https://creativecommons.org/licenses/by/4.0/), which permits unrestricted use,
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