Clindamycin and Triamcinolone in People With Glioblastoma to Prevent Skin-Related Side Effects of Tumor Treating Fields

Inclusion Criteria: * Age ≥18 years * Diagnosis of newly diagnosed or recurrent GBM with plan to initiate treatment with TTFields with or without systemic therapy, confirmed by the enrolling institution * Able to self-administer topical interventions or has available another person who can apply the topical agents * Treatment with TTF should be initiated within 7 days of planned initiation on this trial. Exclusion Criteria: * Known history of allergy to any ingredient of the study agents * Preexisting scalp disorders such as psoriasis or dermatitis that, in the opinion of the investigator, will affect the grading of skin adverse events, confirmed by enrolling institution. * Use of concurrent topical therapy to the scalp for another dermatologic condition * Active, uncontrolled infection requiring systemic or oral antibiotic therapy within 14 days of enrollment * Use of greater than 4 mg dexamethasone a day within 14 days of enrollment * Malignant glioma * Pregnant Women