Mikhael M A
J Comput Assist Tomogr. 1979 Apr;3(2):241-9.
Recurrent symptoms after radiation therapy of a brain tumor are not always the result of regrowth of the neoplasm but may represent radiation necrosis of the brain. Seventeen patients with proven cerebral radionecrosis are included in the present study. In five patients who received 5,000 to 5,500 rads, areas of radiation necrosis of the brain were shown on computed tomography (CT) as low density lesions with no mass effect or contrast enhancement. In 12 patients who received 6,000 to 7,000 rads, radionecrosis was shown on the CT scans either as a localized mass with contrast enhancement or as diffuse low density, isodense, or high density lesions with no mass effect but with occasional enhancement. In all cases, the lesions coincided well with volumes of the brain that received a threshold dose of radiation determined from the isodose reconstruction maps.
脑肿瘤放射治疗后的复发症状并不总是肿瘤再生长的结果，而可能是脑放射性坏死。本研究纳入了17例经证实的脑放射性坏死患者。在接受5000至5500拉德照射的5例患者中，计算机断层扫描（CT）显示脑放射性坏死区域为低密度病变，无占位效应或强化。在接受6000至7000拉德照射的12例患者中，CT扫描显示放射性坏死要么为有强化的局限性肿块，要么为无占位效应但偶尔有强化的弥漫性低密度、等密度或高密度病变。在所有病例中，病变与根据等剂量重建图确定的接受阈值辐射剂量的脑体积吻合良好。
