A novel brainstem tumor model: guide screw technology with functional, radiological, and histopathological...

Area of Science:

• Neuro-oncology
• Animal models
• Surgical techniques

Background:

• High-grade brainstem tumors have poor prognoses with limited therapeutic options.
• Effective preclinical models are crucial for developing novel treatment strategies.
• Current models may not accurately reflect the complexity of human brainstem tumors.

Purpose of the Study:

• To establish and characterize a novel rat model for high-grade brainstem tumors.
• To evaluate the technique, functional progression, and radiological/histopathological features of the model.
• To provide a platform for testing new therapeutic paradigms.

Main Methods:

• Injection of 9L gliosarcoma or F98 glioma cells into the pontine tegmentum of Fischer 344 rats.
• Stereotactic surgery using a cannulated guide screw system for precise tumor cell delivery.
• Postoperative assessment using automated rotarod tests for neurological deficits.
• High-resolution [18F]fluorodeoxyglucose-positron emission tomography (FDG-PET) fused with CT scans for tumor visualization.
• Histopathological analysis for confirmation of tumor characteristics.

Main Results:

• Tumor cells (9L and F98) successfully grew in 95% of injected animals.
• A statistically significant onset of hemiparesis occurred at approximately 16.5 days post-injection (p = 0.001).
• FDG-PET/CT and histological studies confirmed space-occupying brainstem lesions comparable to aggressive human tumors.

Conclusions:

• The developed rat model demonstrates consistent tumor progression and predictable hemiparesis onset.
• The model's histopathological and radiological features closely resemble aggressive human brainstem tumors.
• This validated animal model will facilitate the preclinical testing of novel therapeutic strategies for brainstem gliomas.