Liposomal cytarabine will be given through the Ommaya Reservoir once every 14 days on Day 1 for a total of 12 weeks (6 treatments). This is called Induction Treatment. After the first 12 weeks, liposomal cytarabine will be given on Day 1 every 28 days for 40 weeks (10 treatments). This is called Maintenance Treatment. If you are not already taking daily dexamethasone, you will begin to take dexamethasone by mouth twice a day on the day before the depocyt starts each course and continuing 5 days after the administration of liposomal cytarabine.