Tectal Glioma

Abstract

A 17-year-old female presented asymptomatic. She had history of surgery and conformal radiation therapy for brain stem glioma 6 months ago. The patient was treated with adjunctive; Linac-based SRS for regrowth of residual (post-surgery and post-radiotherapy) tectal astrocytoma (WHO Grade II). The target volume of 3.0 cc received a marginal dose of 11.0 Gy normalized to 85% isodose line. The maximum dose to brain stem was 13.4 Gy. At 2 months post-SRS, the patient developed quadriparesis, probably attributed to the focal mass effect of tumor pseudo-progression and peritumoral vasogenic edema, which required treatment with corticosteroids. This neurological deficit resolved completely at 9 months post-SRS, because of marked regression of both the tumor and brain stem edema. At 14 months post-SRS, follow-up MRI showed disappearance of the tumor, appearance of slightly enhancing, small, focal gliosis at the site of prior tumor, in T1 Gadolinium-enhanced study, and minimal perilesional high signal, in T2 and FLAIR studies. At 48 months post-SRS follow-up, the patient was neurologically intact, got married, and had a baby. At last follow-up (84 months post-SRS), MRI demonstrated sustainable disappearance of the tumor with no evidence of residual or recurrence and complete resolution of brain stem edema.