[abstract] SUCCESSFUL HYPERBARIC OXYGEN THERAPY FOR BIOPSY-PROVEN DELAYED RADIONECROSIS OF THE BRAIN IN A PATIENT WITH CRANIOPHARYNGIOMA

Abstract

BACKGROUND: Craniopharyngiomas constitute about 3% of all intracranial tumors. At least in part, they are almost always located in the suprasellar cistern, where they compress the intracranial portion of the anterior visual pathway. While treatment of craniopharyngiomas usually includes combined surgical and radiation therapies, tumor recurrence is common. The most serious neurologic complication of central nervous system (CNS) radiation is delayed radionecrosis, which occurs in up to 20% of patients depending on the dose and form of delivery. Management options of CNS radionecrosis remain controversial including HBOT. CASE REPORT: A 63-year-old male presented in July 2007 for HBOT for CNS radionecrosis. Three years prior he had undergone subtotal resection of a craniopharyngioma followed by external beam radiation. In this interval, two tumor recurrences had required respective cyst aspirations followed by instillation of P32 first and stereotactic radiosurgery second. Seven months after the last treatment, magnetic resonance imaging (MRI) had revealed increased contrast enhancement in the affected area, as well as prominent bilateral frontal lobes edema. At the time, the patient was exhibiting recent personality and cognitive changes consistent with frontal lobe dysfunction. A subsequent left frontal lobe biopsy had shown benign brain parenchyma with radiation-induced changes. Despite a trial with steroids he had continued to worsen clinically and radiologically. The patient then underwent 40 consecutive HBOT at 2.0 ATA, each of 120 minutes, without complications. He then experienced gradual improvement with complete resolution of the cognitive and personality deficits. Serial brain MRIs showed improvement with reduction of contrast enhancement and complete resolution of edema. At 15-month follow up he remained clinically and radiologically stable. CONCLUSIONS: In our patient with biopsy-proven CNS radionecrosis following treatment of craniopharyngioma, HBOT was successful reverting neurological deficits, and improving MRI appearance with complete resolution of edema and striking reduction of abnormal contrast enhancement.