在所有儿童急性淋巴细胞性白血病(ALL)中,确诊时即合并中枢神经系统病变的大约占3％。美国儿童癌症协作组(CCG)于1978～1983年对上述ALL儿童在治疗的缓解期对脑部放疗24Gy,脊髓放疗12Gy。在CCG 1983～1989年间完成的试验中,对已达到加强缓解期儿童的脊髓放疗剂量减少到6Gy,而未达到加强缓解期儿童的脊髓放疗剂量仍 In all childhood acute lymphoblastic leukemia (ALL), approximately 3% of patients with CNS lesions are diagnosed at the time of diagnosis. The American Childhood Cancer Collaborative Group (CCG) treated 24Gy of brain and 12Gy of radiotherapy for the above ALL children during the remission period from 1978 to 1983. In trials completed between 1983 and 1989 by the CCG, the dose of spinal cordotherapeutics in children who had reached remission was reduced to 6 Gy but did not reach the dose of spinal radiotherapy in children with remission