Patients undergo radiotherapy and receive vorinostat orally (PO) once daily (QD) on days 1-5, 8-12, 15-19, 22-26, 29-33, and 36-40. Patients also receive temozolomide PO QD on days 1-42. Beginning 4-6 weeks later, patients receive vorinostat PO QD on days 1-7 and 15-21 and temozolomide PO QD on days 1-5. Treatment with vorinostat and temozolomide repeats every 28 days for up to 12 courses in the absence of disease progression or unacceptable toxicity.