Post-gadolinium axial T1-weighted MRI showing different outcomes following Gliadel carmustine wafer placement (MGI Pharma, Bloomington, MN, USA). (A) Recurrence in a patient 2 months after tumor resection and Gliadel carmustine wafer placement. Two thick, nodular foci of enhancing tumor are present around the anterior and posterior margins of the surgical cavity. (B) Local control in a patient with stable resection cavity 6 months post-operatively. Thin, linear enhancement is present around the margins of the surgical cavity.