Pioglitazone Hydrochloride in Preventing Radiation-Induced Cognitive Dysfunction in Treating Patients With Brain Tumors

PRIMARY OBJECTIVE: I. To evaluate the tolerability and toxicity associated with two different dose regimens of pioglitazone administered orally as a cytoprotective agent against radiation-induced brain injury. SECONDARY OBJECTIVE: I. To evaluate the effect of pioglitazone on glycemic levels and hemoglobin A1c values when pioglitazone is used as a cytoprotective agent concurrent with radiotherapy in normoglycemic patients. OUTLINE: Patients undergo fractionated external beam radiotherapy, 3-D conformal radiotherapy, or intensity-modulated radiotherapy. Patients receive oral pioglitazone hydrochloride once daily before for 1 week prior to brain irradiation, during and and continuing for 6 months after completion of radiation radiotherapy. After completion of study treatment, patients are followed periodically.