Quality of Life of Patients With Glioblastoma (GBM) Treated With Tumor-Treating Fields

Inclusion Criteria: * Written informed consent prior to beginning specific protocol procedures * Histologically proven World Health Organization (WHO) grade IV malignant glioma * Completed standard-of-care treatment for newly diagnosed WHO grade IV malignant glioma, consisting of temozolomide (TMZ) and radiation therapy (RT) * Signed Optune™ Prescription Form indicating intention of initiating NovoTTF therapy * Stable disease status * Patients ≥ 18 years of age * Karnofsky Performance Status (KPS) ≥ 70 * Patient must be able to ambulate and complete the 6-minute walk test without use of a walker, cane, or any assist device * Technology requirement: * Patients need to own a smart phone that can interface with the Fitbit Charge HR™. * Patients must be willing to provide their own internet access for this study. This will include either a data plan or Wi-Fi access on the patient's smart phone for use of the Fitbit Charge HR™ App. They will also need internet access (through their smart phone or home computer) for setting up a SGHIx account. Patients are welcome to use the free guest Wi-Fi access within the Duke Outpatient clinic area for the purpose of this study. * Patients will need a home computer or adaptor with USB port to charge the Fitbit Charge HR™. Exclusion Criteria: * Non-English speaking or inability to read and understand English. * Presence of cardiovascular disease that would make physical activity risky, at the discretion of the provider. * Any patient who is unable to comprehend and operate the activity tracker, at the discretion of the enrolling provider.