BackgroundBrain
tumours are the most common solid malignancies in children,
encompassing diverse histological, molecular subtypes and imaging
features and outcomes. Paediatric brain tumours (PBTs), including high-
and low-grade gliomas (HGG, LGG), medulloblastomas (MB), ependymomas,
and rarer forms, pose diagnostic and therapeutic challenges. Deep
learning (DL)-based segmentation offers promising tools for tumour
delineation, yet its performance across heterogeneous PBT subtypes and
MRI protocols remains uncertain.MethodsA
retrospective single-centre cohort of 174 paediatric patients with HGG,
LGG, medulloblastomas (MB), ependymomas, and other rarer subtypes was
used. MRI sequences included T1, T1 post-contrast (T1-C), T2, and FLAIR.
Manual annotations were provided for four tumour subregions: whole
tumour (WT), T2-hyperintensity (T2H), enhancing tumour (ET), and cystic
component (CC). A 3D nnU-Net model was trained and tested (121/53
split), with segmentation performance assessed using the Dice similarity
coefficient (DSC) and compared against intra- and inter-rater
variability.ResultsThe
model achieved robust performance for WT and T2H (mean DSC: 0.85),
comparable to human annotator variability (mean DSC: 0.86). ET
segmentation was moderately accurate (mean DSC: 0.75), while CC
performance was poor. Segmentation accuracy varied by tumour type, MRI
sequence combination, and location. Notably, T1, T1-C, and T2 alone
produced results nearly equivalent to the full protocol.
GrantsAnna Valentina Lioba Eleonora Claire Javid Mamasani and the Gemeinntzige Hertie Stiftung Forschungszentrum fr das Kind Universitt Zrich Prof. Max Cloetta Foundation Swiss National Science Foundation EMDO Foundation and Vontobel Foundation