Imaging Biomarkers for Adult Medulloblastomas: Genetic Entities May Be Identified by Their MR Imaging Radiophenotype.

Area of Science:

• Neuro-oncology
• Radiology
• Genetics

Background:

• Adult medulloblastomas are rare but heterogeneous, with distinct genetic and histologic subtypes impacting prognosis.
• Accurate classification of these subtypes is crucial for effective treatment strategies.
• Previous research has not fully elucidated specific MR imaging biomarkers for adult medulloblastoma entities.

Purpose of the Study:

• To identify MR imaging biomarkers for classifying genetic and histologic medulloblastoma entities in adults.
• To compare MR imaging biomarkers found in adult medulloblastomas with those identified in pediatric cohorts.

Main Methods:

• Retrospective analysis of preoperative MRIs from 28 adult patients (NOA-7 cohort).
• Evaluation of lesions and edema using volumetric and multiparametric MR imaging characteristics.
• Correlation of imaging findings with genetic (SHH, WNT, non-WNT/non-SHH/Group 4) and histologic subtypes.

Main Results:

• Six potential MR imaging biomarkers were identified; hydrocephalus, intraventricular macrometastases, and hemorrhage distinguished WNT medulloblastomas.
• WNT-activated medulloblastomas were significantly smaller than other entities.
• Hemorrhage was exclusive to non-WNT/non-SHH medulloblastomas, and MR imaging biomarkers differed from pediatric findings.

Conclusions:

• MR imaging biomarkers can effectively differentiate adult medulloblastoma subtypes.
• The identified MR imaging biomarkers for adult medulloblastomas are distinct from those observed in pediatric cases.
• These findings support the use of advanced MR imaging for improved classification and understanding of adult medulloblastomas.