MRI features of pediatric atypical teratoid rhabdoid tumors and medulloblastomas of the posterior fossa

Hsin-Wei Wu; Chia-Hung Wu; Shih-Chieh Lin; Chih-Chun Wu; Hsin-Hung Chen; Yi-Wei Chen; Yi-Yen Lee; Feng-Chi Chang

doi:10.1002/cam4.5780

MRI features of pediatric atypical teratoid rhabdoid tumors and medulloblastomas of the posterior fossa

Cancer Med. 2023 May;12(9):10449-10461. doi: 10.1002/cam4.5780. Epub 2023 Mar 14.

Authors

Hsin-Wei Wu^{1

2}, Chia-Hung Wu^{1

2

3}, Shih-Chieh Lin^{2

4}, Chih-Chun Wu^{1

2}, Hsin-Hung Chen^{2

5}, Yi-Wei Chen^{2

6

7}, Yi-Yen Lee^{2

5}, Feng-Chi Chang^{1

2}

Affiliations

¹ Department of Radiology, Taipei Veterans General Hospital, Taipei, Taiwan.
² School of Medicine, National Yang Ming Chiao Tung University, Taipei, Taiwan.
³ Institute of Clinical Medicine, National Yang Ming Chiao Tung University, Taipei, Taiwan.
⁴ Department of Pathology and Laboratory Medicine, Taipei Veterans General Hospital, Taipei, Taiwan.
⁵ Division of Pediatric Neurosurgery, Department of Neurosurgery, Neurological Institute, Taipei Veterans General Hospital, Taipei, Taiwan.
⁶ Department of Oncology, Taipei Veterans General Hospital, Taipei, Taiwan.
⁷ Department of Medical Imaging and Radiological Technology, Yuanpei University of Medical Technology, Hsinchu City, Taiwan.

Abstract

Background: Atypical teratoid rhabdoid tumor (AT/RT) occurs at a younger age and is associated with a worse prognosis than medulloblastoma; however, these two tumor entities are mostly indistinguishable on neuroimaging. The aim of our study was to differentiate AT/RT and medulloblastoma based on their clinical and MRI features to enhance treatment planning and outcome prediction.

Methods: From 2005-2021, we retrospectively enrolled 16 patients with histopathologically diagnosed AT/RT and 57 patients with medulloblastoma at our institute. We evaluated their clinical data and MRI findings, including lesion signals, intratumoral morphologies, and peritumoral/distal involvement.

Results: The age of children with AT/RT was younger than that of children with medulloblastoma (2.8 ± 4.9 [0-17] vs. 6.5 ± 4.0 [0-18], p < 0.001), and the overall survival rate was lower (21.4% vs. 66.0%, p = 0.005). Regarding lesion signals on MRI, AT/RT had a lower ADC_min (cutoff value ≤544.7 × 10^-6 mm² /s, p < 0.001), a lower ADC ratio (cutoff value ≤0.705, p < 0.001), and a higher DWI ratio (cutoff value ≥1.595, p < 0.001) than medulloblastoma. Regarding intratumoral morphology, the "tumor central vein sign" was mostly exclusive to medulloblastoma (24/57, 42.1%; AT/RT 1/16, 6.3%; p = 0.007). Regarding peritumoral invasion on T2WI, AT/RT was more prone to invasion of the brainstem (p < 0.001) and middle cerebellar peduncle (p < 0.001) than medulloblastoma.

Conclusions: MRI findings of a lower ADC value, more peritumoral invasion, and absence of the "tumor central vein sign" may be helpful to differentiate AT/RT from medulloblastoma. These distinct MRI findings together with the younger age of AT/RT patients may explain the worse outcomes in AT/RT patients.

Keywords: atypical teratoid rhabdoid tumor (AT/RT); embryonal brain tumor; magnetic resonance imaging (MRI); medulloblastoma; pediatric brain tumor.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Central Nervous System Neoplasms*
Cerebellar Neoplasms* / diagnostic imaging
Cerebellar Neoplasms* / pathology
Child
Humans
Magnetic Resonance Imaging
Medulloblastoma* / diagnostic imaging
Medulloblastoma* / pathology
Retrospective Studies
Rhabdoid Tumor* / diagnostic imaging
Rhabdoid Tumor* / pathology
Teratoma* / diagnostic imaging
Teratoma* / pathology