RT Journal Article
SR Electronic
T1 MRI Surrogates for Molecular Subgroups of Medulloblastoma
JF American Journal of Neuroradiology
JO Am. J. Neuroradiol.
FD American Society of Neuroradiology
DO 10.3174/ajnr.A3990
A1 S. Perreault
A1 V. Ramaswamy
A1 A.S. Achrol
A1 K. Chao
A1 T.T. Liu
A1 D. Shih
A1 M. Remke
A1 S. Schubert
A1 E. Bouffet
A1 P.G. Fisher
A1 S. Partap
A1 H. Vogel
A1 M.D. Taylor
A1 Y.J. Cho
A1 K.W. Yeom
YR 2014
UL http://www.ajnr.org/content/early/2014/05/15/ajnr.A3990.abstract
AB BACKGROUND AND PURPOSE: Recently identified molecular subgroups of medulloblastoma have shown potential for improved risk stratification. We hypothesized that distinct MR imaging features can predict these subgroups. MATERIALS AND METHODS: All patients with a diagnosis of medulloblastoma at one institution, with both pretherapy MR imaging and surgical tissue, served as the discovery cohort (n = 47). MR imaging features were assessed by 3 blinded neuroradiologists. NanoString-based assay of tumor tissues was conducted to classify the tumors into the 4 established molecular subgroups (WNT, sonic hedgehog, group 3, and group 4). A second pediatric medulloblastoma cohort (n = 52) from an independent institution was used for validation of the MR imaging features predictive of the molecular subtypes. RESULTS: Logistic regression analysis within the discovery cohort revealed tumor location (P < .001) and enhancement pattern (P = .001) to be significant predictors of medulloblastoma subgroups. Stereospecific computational analyses confirmed that group 3 and 4 tumors predominated within the midline fourth ventricle (100%, P = .007), WNT tumors were localized to the cerebellar peduncle/cerebellopontine angle cistern with a positive predictive value of 100% (95% CI, 30%–100%), and SHH tumors arose in the cerebellar hemispheres with a positive predictive value of 100% (95% CI, 59%–100%). Midline group 4 tumors presented with minimal/no enhancement with a positive predictive value of 91% (95% CI, 59%–98%). When we used the MR imaging feature–based regression model, 66% of medulloblastomas were correctly predicted in the discovery cohort, and 65%, in the validation cohort. CONCLUSIONS: Tumor location and enhancement pattern were predictive of molecular subgroups of pediatric medulloblastoma and may potentially serve as a surrogate for genomic testing. Abbreviations CP/CPAcerebellar peduncle/cerebellopontine angle cisternFSLfMRI of the Brain Software LibrarySHHsonic hedgehogWNTwingless