Delayed radiation necrosis of the brain

Area of Science:

• Neurology
• Radiology
• Oncology

Background:

• Delayed radiation necrosis of the brain is a significant complication following radiotherapy for intracranial neoplasms.
• Understanding its clinical presentation is crucial for accurate diagnosis and management.

Purpose of the Study:

• To delineate the clinical profile of delayed radiation necrosis of the brain.
• To identify diagnostic features that may obviate the need for surgical intervention.

Main Methods:

• Case study of six patients with delayed radiation necrosis of the brain.
• Histological verification of diagnosis in five patients.
• Review of clinical symptoms, electroencephalography, radionuclide brain scans, and computerized tomography findings.

Main Results:

• Symptoms typically manifest 9 months to 2 years after radiotherapy.
• Perisellar irradiation is associated with visual impairment and dementia; cerebral irradiation with hemispheric signs.
• Elevated cerebrospinal fluid protein, focal delta slowing on electroencephalography, abnormal uptake on radionuclide scans, and diminished absorption coefficient with contrast enhancement on CT are characteristic findings.

Conclusions:

• The clinical and imaging features of delayed radiation necrosis can be sufficiently characteristic to avoid surgical exploration.
• The risk-benefit ratio of radiotherapy for benign intracranial neoplasms may be unfavorable with doses exceeding 5000-7000 rads fractionated at >200 rads/day.