Recurrent glioblastoma multiforme (GBM) in a 55-year-old man before and after hypofractionated stereotactic radiotherapy by intensity modulated radiation therapy (HS-IMRT). Before HS-IMRT, two enhanced lesions (long and short arrow) were demonstrated in the left temporal lobe on T1-weighted magnetic resonance imaging (A). 11C-methionine positron emission tomography (MET-PET) demonstrated a MET high-uptake on the region of short arrow, which was defined as the Gross Tumor Volume (red line) (B). 5 months after HS-IMRT, there was no tumor recurrence on the lesion (long arrow, C &D). The enhanced lesion (short arrow) was increased in size (C), although MET uptake decreased relative to normal tissue, which suggested a necrotic change in the irradiated region (D). The patient had no neurologic deficits or quality of life issues. KPS was 90%.