Recurrent Glioblastoma Multiforme: Implication of Nonenhancing Lesions on Bevacizumab Treatment

Abstract

Daniela Alexandru, Hung-Wen Kao, Ronald Kim, , Mark E. Linskey, Anton N. Hasso, Daniela A. Bota

Glioblastoma multiforme (GBM) is the most common primary brain tumors, accounting for 15- 20% of all intracranial tumors. It is one of the most lethal tumors of the central nervous system with a median survival from diagnosis on the order of 6 to 18 months. Despite aggressive resection and chemoradiation, the tumor always recurs. Magnetic Resonance (MR) imaging is an essential component in the diagnosis, treatment planning, and following response. However, the imaging features of recurrent GBM may be challenging, particularly in patients undertaking novel antiangiogenic therapy. We present such a case treated with repeated surgeries, combined chemoradiation, and bevacizumab. The patient benefited from the regimen with a 6-month progression-free survival, evidenced on both stable clinical condition and MR imaging findings. However, despite chemotherapy, a fulminant progression developed with growth multiple tumors in different locations and variable imaging characteristics, ranging from typical enhancing nodules to nonenhancing signal changes. The lesions of different imaging features were biopsy-proved to be recurrent GBM. We discuss the use of MR imaging in the evaluation of GBM treated with bevacizumab and emphasize the implication of signal abnormality on fluid-attenuated inversion recovery (FLAIR) images for early evidence of recurrence.