64例髓母细胞瘤放疗的回顾性分析

目的分析髓母细胞瘤放疗疗效及预后影响因素,观察最常见的放疗副反应。方法回顾性分析接受放疗的髓母细胞瘤64例,年龄均≥4岁。术前中枢神经系统MRI检查无蛛网膜下腔播散迹象,属Chang’sM分期M0～M1期。所有病例均在外院接受了原发肿瘤的全切或次全切除手术。放疗先予全脑全脊髓照射30Gy,然后缩野至后颅窝局部加量20～25Gy,中位分次剂量为180cGy。结果所有病例均完成了放疗,全组3、5年总生存率分别为68.8%和55.7%,无病生存率分别为57.8%和51.4%,27例(42.2%)在3年内复发。通过分析年龄、性别、原发肿瘤大小、手术与放疗间隔时间对生存率影响发现,只有手术与放疗间隔时间有一定影响,手术与放疗间隔时间≤25、>25d的3年总生存率分别为81.5%、59.5%(P=0.110),3年无病生存率分别为74.1%、46.0%(P=0.030)。放疗中最常见的副反应主要为白细胞下降,92.2%的病例在治疗中出现了白细胞下降(<4.0×109/dl),其中2～3级的血液系统毒性占64.0%。结论髓母细胞瘤通过手术与放疗结合能取得较好疗效,但治疗失败率较高。手术与放疗间隔延长对总生存率和无病生存率均有影响,年龄、性别、原发肿瘤大小不是明显预后因素,放疗中最常见的副反应为血液毒性。

A retrospective study of 64 medulloblastomas

Objective Sixty-four patients with medulloblastoma treated at a single hospital are presented, with the results, prognostic factors and the most common acute side effect of radiotherapy analyzed. Methods From Jan. 1996 to Apr. 2001, 64 patients with medulloblastoma, by Chang's staging system M0-M1 were admitted for radiotherapy in our hospital after total or sub-total resection of the primary tumor done elsewhere. All patients were over 4 years old. The patients were irradiated with the same technique: 30?Gy delivered to the whole craniospinal axis followed by a 20-25?Gy boost to the posterior fossa, with a median fraction dose of 180?cGy. Results All patients have been followed for at least 3 years or till death. The overall 3-and 5-year survival rates were 68.8% and 55.7% respectively, disease-free survival 57.8% and 51.4%. Twenty-seven (42.2%) patients developed recurrent disease within 3 years. The effect of age, sex, tumor size and interval between surgery and radiation on survival were studied, showing only the interval between surgery and radiation had obvious impact on the patients' survival. Patients whose radiation treatment had been started within 25 days after operation showed a better survival than those beyond the 25th day, with 3-year overall survival of 81.5% and 59.5% (P=0.110)and 3-year disease-free survivals of 74.1% and 46.0% respectively (P=0.030), while relation between survival and age, sex, tumor size was irrelevant. During the course of irradiation, the most common side effect was hematological toxicity, especially the WBC reduction which was observed in 92.2% of patients, with 64.0% of them suffering from grade 2-3 hematological toxicity. Conclusions Surgery plus craniospinal irradiation is able to give a good result for medulloblastoma, though being dwarfed by a high incidence of recurrence. The interval between surgery and radiation is a significant prognostic factor for disease-free survival. Age, sex and tumor size are not. The most common acute side effect is hematological toxicity.