Is there an increased risk of spinal relapse in standard-risk medulloblastoma/primitive neuroectodermal tumor patients who receive only a reduced dose of craniospinal radiotherapy?

PURPOSE: Medulloblastoma (MBL) is the most common pediatric brain malignancy. Postoperative radiotherapy to the entire craniospinal axis is the standard-of-care but has linked to long-term morbidity. In this study, we analyzed the implication of reduced dose craniospinal radiotherapy (RT) for survival and pattern of relapse in MBL patients. MATERIAL AND METHODS: The clinical characteristics of 32 consecutively diagnosed medulloblastoma/primitive neuroectodermal tumor patients were analyzed. After surgical resection, a dose of 23.4 Gy of spinal RT with a posterior fossa boost of 30.6 Gy was prescribed to standard-risk patients, whereas high-risk patients received 36 Gy spinal RT with additional boosts to the posterior fossa up to 54 Gy. Then, both groups received the same chemotherapy protocol. RESULTS: Five-year OS for standard and high-risk patients was 94 and 50%, respectively. When analyzing prognostic factors, postoperative tumor size is the most important one which affects the OS. Ten patients relapsed during follow-up, and there was no isolated spinal relapse in either group. CONCLUSION: The risk of isolated spinal relapse does not increase with reduced-dose craniospinal RT, since there is no isolated relapse in either the standard or high-risk groups of patients.

Neuro-Behçet’s disease mimicking cerebral abscesscomplicated by metronidazole-induced encephalopathy

This is the report of a 32-year-old man with Behçet’s disease described dizziness, double vision and headache. The cranial MRI demonstrated a ring enhancing nodular lesion in left medial occipital lobe, and T2 hyperintense lesion in diencephalon mimicking abscesses. A stereotactic biopsy was performed. The histology showed features of neuro-Behçet’s disease and an abscess was ruled out. During the procedure till the histopathologic results were gathered he was given ceftriaxone and metronidazole when cerebellar signs appeared. Cranial MRI showed additional symmetrical hyperintensities in bilateral cerebellar dentate nuclei which was attributed to metronidazole toxicity. Repeat MRI performed forty days later showed complete resolution of both dentate hyperintensities and diencephalic and occipital ring enhancing lesions. This is the first case of neuro-Behcet’s disease complicated by metronidazoleinduced encephalopathy. This case also showed that nodular ring enhancing lesions can be seen in neuro-Behçet’s disease and can lead to difficulties in diagnosis and management.