Intrathecal chemotherapy for refractory disseminated medulloblastoma
To analyze the effect of intrathecal (IT) chemotherapy for disseminated medulloblastoma. Twenty-one patients received IT chemotherapy using the chemotherapeutic agents of methotrexate (MTX) and nitrosoureas (ACNU, MCNU) including nine patients for residual leptomeningeal lesions after initial surgery and radiation, and 12 for a recurrence with leptomeningeal dissemination. Of these 21 patients, 12 received a lumbar and/or ventricular bolus injection of the chemotherapeutic agents, one received the ventriculolumbar perfusion of the agents, and eight received both the perfusion and bolus injection. The doses ranged from 6–7 mg/m2 of ACNU for perfusion and 3–3.5 mg/m2 of ACNU, MCNU, or MTX for the bolus injection, and the cycles were administered from 3 to 12 times for perfusion and from 5 to 54 times for the bolus injection. The effects of chemotherapy were assessed by both radiological and cytological examinations, and the clinical symptoms were also assessed. Radiological and/or cytological responses were observed in 10 of 21 patients (47.6%), including seven cases demonstrating a complete remission. The 5-year overall survival rate and 5-year survival rate after dissemination were 61.5 and 46.4%, respectively. Five patients who received a lumbar bolus injection of nitrosoureas experienced paraplegia and double incontinence. One patient who received a ventricular injection of nitrosoureas experienced truncal ataxia. IT chemotherapy was found to be effective in some cases with refractory disseminated medulloblastoma and it seems to be an appropriate treatment choice for leptomeningeal recurrence. However, the frequent bolus injections of nitrosoureas should be avoided to prevent the side effects.