<qa>  What is the CYVE-RM regimen?CNS-POSITIVE DISEASE: Patients receive 2 courses of the CYVE-RM regimen comprising rituximab IV and methotrexate and hydrocortisone IT on day 0; cytarabine IV over 12 hours on days 0-4; high-dose cytarabine IV over 3 hours and etoposide IV over 2 hours on days 1-4; and G-CSF SC on days 6-20. During the first course, patients also receive HD-MTX IV over 4 hours on day 17; TIT on day 18; and leucovorin calcium IV or orally every 6 hours on days 18-21 12 doses. 