Constine L S, Konski A, Ekholm S, McDonald S, Rubin P
Dept. of Radiation Oncology, University of Rochester, NY 14642.
Int J Radiat Oncol Biol Phys. 1988 Aug;15(2):319-30. doi: 10.1016/s0360-3016(98)90011-6.
Forty-one patients treated for primary malignancies of the brain at the University of Rochester Cancer Center since 1970 were assessed for adverse effects of irradiation clinically, and by computerized tomography (CT) and magnetic resonance (MR) imaging. At diagnosis, patients ranged in age from 1-65 years (median 19 years) and the most common tumor (in 30) was astrocytoma. Radiation doses ranged from 45 to 81.3 Gy (median 56.8 Gy). White matter changes visible on MR were graded on a scale of 1-4, with grades 1-2 known to occur in some normal patients. Areas of increased signal intensity not associated with the tumor or surgery were visible in all patients (gr 1 = 37%, gr 2 = 32%, gr 3 = 17%, gr 4 = 15%) whereas only 35% had regions of abnormality (hypodensity) on CT. Sulci enlargement and ventricular abnormalities (asymmetry or dilatation) were present in approximately 50% of patients by each technique. Higher grade MR lesions were associated with radiation to large volumes and high doses. For the 36 patients treated with 1.5-2.0 Gy daily fractions, the mean radiation dose by grade was as follows: gr 1 = 55.1 Gy, gr 2 = 58.8 Gy, gr 3 = 60.0 Gy, gr 4 = 63.5 Gy. All 5 patients treated on a hyperfractionated schedule had gr 1-2 changes despite receiving greater than 70 Gy. Fifty percent of patients treated to the whole brain (+/- boost) had gr 3-4 changes, compared with 14% treated with local fields (peak dose regions similar in both groups). Among the children (less than or equal to 13 years), 20% had gr 3-4 changes compared with 56% of adults (excluding hyperfractionated patients). This finding may be due entirely or in part to the lower radiation doses used for children (mean 54.4 Gy vs. 63.7 Gy in adults). Clinical abnormalities attributable to irradiation included an impairment in mental functioning in 7 adults, and learning disabilities in 5 children. Five of these adults (71%) had gr 3-4 changes on MR as compared to gr 3-4 changes in 29% of the remaining adult group. Five patients developed seizure disorders. We conclude that adverse effects of brain irradiation are more sensitively imaged by MR than CT and that these abnormalities are associated with larger treatment volumes and either (or both) higher doses or older age. Conversely, some patients treated with high radiation doses have unremarkable changes on MR, and others have severe white matter changes which are not clinically expressed.(ABSTRACT TRUNCATED AT 400 WORDS)
自1970年以来，在罗切斯特大学癌症中心接受原发性脑恶性肿瘤治疗的41例患者，通过临床、计算机断层扫描（CT）和磁共振（MR）成像对放疗的不良反应进行了评估。诊断时，患者年龄在1至65岁之间（中位年龄19岁），最常见的肿瘤（30例）为星形细胞瘤。放疗剂量范围为45至81.3 Gy（中位剂量56.8 Gy）。MR上可见的白质变化按1至4级分级，1至2级在一些正常患者中也会出现。所有患者均可见与肿瘤或手术无关的信号强度增加区域（1级 = 37%，2级 = 32%，3级 = 17%，4级 = 15%），而只有35%的患者在CT上有异常区域（低密度）。通过每种技术，约50%的患者存在脑沟增宽和脑室异常（不对称或扩张）。较高等级的MR病变与大体积照射和高剂量照射有关。对于每天分次给予1.5 - 2.0 Gy治疗的36例患者，按等级划分的平均放疗剂量如下：1级 = 55.1 Gy，2级 = 58.8 Gy，3级 = 60.0 Gy，4级 = 63.5 Gy。所有5例接受超分割方案治疗的患者尽管接受了大于70 Gy的剂量，但仍有1 - 2级变化。接受全脑照射（±增强）的患者中有50%出现3 - 4级变化，而局部野照射的患者为14%（两组的峰值剂量区域相似）。在儿童（小于或等于13岁）中，20%出现3 - 4级变化，而成人（不包括超分割治疗患者）为56%。这一发现可能完全或部分归因于儿童使用的放疗剂量较低（儿童平均54.4 Gy，成人平均63.7 Gy）。放疗引起的临床异常包括7例成人的精神功能损害和5例儿童的学习障碍。这些成人中有5例（71%）在MR上有3 - 4级变化，而其余成人组中这一比例为29%。5例患者出现癫痫发作障碍。我们得出结论，脑放疗的不良反应在MR上比在CT上成像更敏感，并且这些异常与更大的治疗体积以及更高剂量或更高年龄（或两者）相关。相反，一些接受高放疗剂量的患者在MR上变化不明显，而另一些患者有严重的白质变化但无临床症状。（摘要截取自400字）
