三维适形放疗在中枢神经系统白血病预防和治疗中的应用

Application of 3-D Comformal Radiation Therapy in Prophylaxis and Treatment in Central Nervous System Leukemia

目的探讨三维适形放疗在中枢神经系统(CNS)白血病预防和治疗中的应用。方法回顾性分析28例急性淋巴细胞性白血病患者CNS预防或治疗方案,头颅三维适形放疗的方法、剂量以及疗效随访情况。结果7例CSF(-)者中枢预防放疗剂量12.6～18Gy/7～10Fx,诊断CNS白血病者放疗剂量18～23.4Gy/10～13Fx,脑实质占位性病变者全颅放疗21.6～24Gy后局部加量4～8Gy/2～4Fx。剂量偏差<10%,摆位误差范围3～5mm。随访6～55个月,所有患者存活,放疗中枢控制率82.1%。结论三维适形放疗可以准确地针对整个脑膜,不产生低剂量区,便于临床医生对放疗的副作用进行明确的剂量观察。头颅放疗控制和治疗发生最小副反应的剂量点在18Gy。

Objective To discuss the application of quality assurance in cranial radiation therapy and its development in central nervous system（CNS） leukemia. Methods A total of 28 patients were retrospectively analyzed of the prophylactic or therapeutic protocols of cranial radiation therapy, the methods and dosages of 3-D comformal radiation. Results Seven patients with CSF （-） were treated with prophylactic whole brain external beam irradiation 12.6-18 Gy/7-10 Fx. Those patients diagnosed with CNS leukemia were treated with 18-23.4 Gy/10-13 Fx. The patients with brain tumors in CNS were treated with additional 4-8 Gy/2-4 Fx focused on the tumor after whole brain external beam irradiation 21.6-24 Gy. The deviation of the radiation dosages was 〈10. The deviation of radiation area is about 3-5 mm. With 6-55 months follow-up, the control remission rate of CNS was 82. 1%. Conclusion The recommended dosage for CR is 18 Gy, which has the best quality assurance and least side-effects. 3-D comformal radiation is able to focus the beam onto the whole brain membranes, not yielding low-dosage area, and it is more convenient for the radiation therapist to supervise the radiation dosage.