1280. Radiation necrosis after stereotactic radiosurgery for trigeminal neuralgia

Authors: Alick Wang; Tanishq Suryavanshi; Maura Marcucci, MD; Crystal Fong, MD; Kesava Reddy, MBBS; Anthony Whitton, MBBS (Hamilton, Canada)

Introduction: Stereotactic radiosurgery is a relatively safe treatment modality for many types of pathology in the neuraxis, including trigeminal neuralgia. Radiation necrosis is a well-documented complication of stereotactic radiosurgery, especially in the treatment of central nervous system malignancy. However, the true incidence of radiation necrosis following stereotactic radiosurgery for trigeminal neuralgia is unknown. Case Report: An 85-year-old man with a history of stereotactic radiosurgery to the right Gasserian ganglion for trigeminal neuralgia presented to the emergency room with dysarthria, hemiparesis and numbness. Magnetic resonance imaging demonstrated a ring-enhancing lesion in the right mesial temporal lobe with surrounding vasogenic edema and the patient was diagnosed with high-grade glioma. Repeat examination 4 months later revealed an interval decrease in the lesion size and surrounding edema. Magnetic resonance spectroscopy demonstrated decreased N-acetylaspartate (NAA) but relatively preserved choline (Cho), with a reversal of the Cho/NAA ratio. The patient was diagnosed with radiation necrosis based on radiological and clinical criteria. Conclusion: This is the second reported case of radiation necrosis following stereotactic radiosurgery for trigeminal neuralgia. We review the literature and explore the clinical and radiographic manifestations of this phenomenon. Our report specifically highlights the importance of recognizing this rare but important entity and contributes to a better understanding of stereotactic radiosurgery for trigeminal neuralgia.