Deformational changes after convection-enhanced delivery in the pediatric brainstem

Area of Science:

• Neuro-oncology
• Neurosurgery
• Medical Imaging

Background:

• Convection-enhanced delivery (CED) is used for brainstem tumors like diffuse intrinsic pontine glioma (DIPG).
• Volumetric changes in the brainstem and ventricles following CED are a concern.
• The clinical impact of these volumetric alterations is not well understood.

Purpose of the Study:

• To measure treatment-related volumetric alterations in the brainstem and ventricles after CED for DIPG.
• To assess the relationship between infusion volume and observed volumetric changes.
• To understand the implications for clinical management and neuroimaging interpretation.

Main Methods:

• Analysis of pre- and postoperative MRI scans (POD1 and POD30) from 23 DIPG patients treated with CED.
• Semiautomated volumetric measurements of the pons and lateral ventricles using iPlan® Flow software.
• Statistical analysis including paired t-tests and correlation coefficients.

Main Results:

• Significant immediate increase in pontine volume post-CED, trending back to baseline by POD30.
• Significant increase in lateral ventricle volume, persisting at POD30.
• Weak positive correlation between infusion volume and changes in pontine and ventricular volumes.
• Four patients experienced increased neurological deficits; none required shunt placement.

Conclusions:

• CED infusion into the brainstem causes immediate, self-limited pontine deformation.
• Persistent ventricular enlargement is not indicative of obstructive hydrocephalus.
• Characterizing these volumetric changes aids in interpreting neuroimaging in DIPG patients undergoing CED.