International Registry Uses MRI to Learn Imaging Features of DIPG

Published November 2020 | Neuro-Oncology

In children, 80% of brain stem tumors are categorized as diffuse, poorly defined. Compared to other types of tumors, diffuse intrinsic pontine glioma (DIPG) may be relatively uncommon but they are most often lethal. Diagnosis is usually based upon imaging, but previous single-institution studies of imaging for these tumors have had mixed results in showing how MRI findings relate to survival.

Now, a report from the International DIPG Registry represents the largest and most detailed assessment of MRI findings in DIPG. This study analyzed imaging from 357 patients, drawing from a pool of over 1,200 patients from 116 institutions enrolled in the registry.

“We found that the presence of tumor necrosis, contrast enhancement, visible diffusion restriction, and most importantly, distant disease at diagnosis, correlated with worse survival in these patients,” says first author James Leach, MD, a neuroradiologist at Cincinnati Children’s.

On multivariable analysis, both age and distant disease were significantly associated with overall survival. Also, baseline imaging showed a 9.5% discordance in DIPG diagnosis between local and central review, which demonstrated the need for central imaging confirmation for prospective trials.

Organizing so much clinical, pathological, and imaging data from numerous institutions was a major challenge—a task met by the team’s research PACS application and imaging core specialists. Research from this study has been presented at American Society of Neuroradiology, the International Symposium on Pediatric Neuro-Oncology, and Society for Neuro-Oncology conferences.

Looking ahead, researchers plan to begin evaluating changes in imaging during treatment to track outcomes of differing therapy regimens.

Examples of submitted cases classified as characteristic of DIPG. (T2: T2-weighted, T1: T1-weighted, +C: post contrast T1-weighted, GR: Gradient recalled echo, DW: Diffusion weighted). A. Classic infiltrative pontine lesion with minimal enhancement. B. More heterogenous signal on T2 but characteristic. C. Spotty minimal areas of hemorrhage on GR (GR, arrows), with patchy enhancement. D. Mildly heterogenous with more localized area of diffusion restriction (DW, arrow) and relative T2 hypointensity.