Figure 13b. Intracranial balloon system in a 41-year-old woman treated for glioblastoma multiforme. Lateral radiograph of the skull (a) and CT scan (b) of the cranium show an intracranial balloon system (GliaSite balloon; Proxima Therapeutics, Alpharetta, Ga) for the installation of radioactive iodine. In a, note the scalp (skin) staples and the cranial bone staples from recent intracranial surgery. In b, note the polymer wafer (arrow) impregnated with carmustine (BCNU), which shows up only as a thin white line because of its small size (1.45-cm diameter, 1-mm thickness).