Patients will continue monthly cycles of treatment for 12 cycles or until disease progression or unacceptable toxicity (whichever occurs first). For those in Arm B, patients may continue NovoTTF-200A treatment if temozolomide is discontinued early for toxicity. An end of treatment visit for clinical evaluations and safety assessments will be performed approximately four to six weeks of withdrawing from study treatment. Patients discontinuing study treatment will be followed at months 18 and 24 with tumor assessments if they discontinued from study treatment without disease progression and for survival.