[Complication of irradiation in brain tumors]

Examination by questionnaire throughout the country revealed 97 cases of radiation brain necrosis (RN). Of the above 97 cases, histologically confirmed 39, having received one course of radiation therapy received an average dose of 62 +/- 10.6 Gy. Minimal total dose provocative of RN is estimated statistically to be 40.6 Gy. Safety fractionation for total dose is regarded as standard in case of 1.8 Gy per once by 22 fractionations for a total dose of 40 Gy and of 1.4 Gy per once by 36 fractionations for a total dose of 50 Gy. After left frontotemporal craniotomy for pituitary adenoma, postoperative opposing 2 fields irradiation brought about right RN on the right side. Examination by means of PET is useful for the differentiation RN from recurrence of malignant glioma. The appearance of foam cells in tunica intima arteriole in substance alba and subsequent luminal narrowing are interesting histological findings in RN.