LTS patient with radiation-induced GBM. (A) One LTS was initially diagnosed with IDH-wildtype, TERT-mutant GBM (top row, H&E at 20 and 40x magnification). Scale bars reflect 200 µm and 100 µm, respectively. Almost 15 years later, the patient developed an IDH-wildtype, TERT-wildtype GBM (bottom row, H&E at 20 and 40x, respectively). (B) Preoperative MRI scans of the initial GBM (top row) highlight lesions in the right frontal lobe. The recurrence (bottom left) arose within the prior radiation field (dosimetry shown in bottom row) that received between 3000 and 6000 cGy. (C) Chromosomal analysis revealed a highly complex profile in the recurrent GBM relative to the initial tumor.