RTRB-20: CALCIFICATION AFTER RADIOTHERAPY IN GLIOBLASTOMA: A CASE REPORT

BACKGROUND: Radiation necrosis, vasculopathy, leucencephalopathy, edema or bleeding are well known delayed effects of cerebral radiation which are well documented by imaging techniques. Mineralizing microangiopathy is a late complication of radiation-induced brain injury in children and adults and has also been observed in combinations with chemotherapy and radiotherapy. We present a case of calcification in the radiated area of the tumor one year after treatment. INDEX CASE: A 42-year-old man was diagnosed with glioblastoma in the basal ganglia and the insular region on the right side. Clinically he presented with a high grade sensorymotor brachiofacial hemiparesis on the left side and neglect. After biopsy he received combined radiotherapy and chemotherapy according to Stupp-regimen. A volumetric modulated arc therapy with a total dose of 60 Gy (30 x 2 Gy) was performed. The disease was stable clinically and radiologic for one year. Then he was readmitted due progression of the hemiparesis and development of an optomotor disturbance. A cerebral CT scan revealed a calcification of the basal ganglia and in the prepontine area. The location matched exactly the former radiation field. A reevaluation of histology confirmed GMB and no indication for oligodendroglioma was noted. DISCUSSSION: Calcifications as a consequence of mineralizing microangiopathy after combined radiation and chemotherapy are described in childhood CNS neoplasms. Typical locations are the basal ganglia and subcortical white matter. In this index case, the large calcified area in the field of radiation is an unusual finding with unclear significance. As this is a rarely reported observation the prognostic relevance is not clear.