34例髓母细胞瘤的预后因素分析

Analyses of Prognostic Factors for 34 Cases with Medulloblastoma

背景与目的:髓母细胞瘤是儿童后颅窝常见的恶性肿瘤,手术加术后全脑全脊髓放疗是主要的治疗方法,本文回顾性分析34例髓母细胞瘤的预后因素。方法:1992年1月至2002年12月,34例术后病理证实的小脑髓母细胞瘤患者在我院接受了术后全脑全脊髓放疗,照射源为6MV x-射线或者^(60)Coγ射线。全脑照射2850～3500 cGy,150～180 cGy/次,后颅窝瘤床缩野加量照射2000～2500 cGy,180～200 cGy/次。全脊髓照射2960～3210 cGy,150～180 cGy/次。14例在放疗结束后接受了全身化疗,方案为DDP+VM26或者DDP+VCR+CCNU,化疗周期为2～4个。运用SPSS 10.0统计学软件进行数据处理,采用Kaplan-Meier法计算生存率,对年龄、性别、手术切除程度、放疗前卡氏评分、射线种类、手术和放疗的时间间隔、化疗等潜在的影响预后的因素采用单因素和多因素分析,生存率之间的差异采用log-rank法检验。结果:34例患者在放疗过程中均发生了不同程度的骨髓抑制,其中Ⅰ度骨髓抑制6例,Ⅱ度25例,Ⅲ度3例。全组5年总生存率为58.8%,无病生存率为53.2%;单因素分析发现年龄、手术切除程度、放疗前卡氏评分影响预后,其中年龄≥10岁、术后完整切除、放疗前卡氏评分≥80的5年总生存率分别为73.7%、82.4%、73.1%;无瘤生存率分别是68.4%、76.5%、68.0%;年龄<10岁、术后残留、放疗前卡氏评分<80的5年总生存率分别为40.1%、35.3%、12.5%,无瘤生存率分别是30.8%、26.8%、0.0%;而性别、射线种类、化疗、术后放疗的时间间隔不影响预后。多因素分析进一步证实年龄、手术切除程度、放疗前卡氏评分是预后的影响因素。结论:全脑全脊髓放疗的主要急性不良反应是骨髓抑制。年龄、手术切除程度、放疗前卡氏评分是影响髓母细胞瘤的预后因素。年龄≥10岁、术后完整切除、放疗前卡氏评分≥80的患者预后较好。

BACKGROUND & OBJECTIVE: Medulloblastoma is one of the most common malignant tumors in the posterior cranial fossa in children. Surgery with postoperative whole central nervous system radiothera-py is the main consideration in the treatment of medulloblastoma. This study was to retrospectively evaluate the prog-nostic factors of 34 cases with medulloblastoma treated in the department of radiation oncology, Fudan University Affiliated Cancer Hospital. METHODS: Thirty-four cases with histopathologically proved medulloblastoma were treat-ed with postoperative radiotherapy from January 1992 to December 2002. All patients received craniospinal irradia-tion with 6MV x-ray or ^(60)Co gamma rays. The prescribed dose was 2850-3 500cGy to the whole brain (150-180 cGy per fraction), and a boost of 2000-2500cGy to the tumor bed with shrinking fields (180-200 cGy per fraction). The dose to the whole spinal cord was 2960-3210 cGy(l50-180 cGy per fraction). Fourteen cases also received sys-temic chemotherapy after radiation therapy.The chemotherapy regimen was 2 to 4 cycles of DDP+VM26 or DDP+VCR+CCNU. All the data were analyzed with SPSS10.0 statistic software. The survival rate was calculated using Kaplan-Meier method. The potentially prognostic factors such as age, gender, range of resection, preradiotherapeutical Karnofsky(KPS), radiation source, the interval between surgery and radiotherapy,and chemotherapy, were tested by both uni-variant and multi-variant analysis. And the difference between sur-vival rates were tested by Log-rank method. RESULTS: Radiation induced leukopenia was found in all patients during the course of radiotherapy. Among them, 6 cases had grade Ⅰ leukopenia, 25 with grade Ⅱ, and 3 with grade Ⅲ. The 5-year overall survival rate was 58.8%, and event-free survival rate was 53.2%. Uni-variant analysis showed that age, surgical resection, and preradiotherapeutical KPS had impact on prognosis. The 5-year overall survival rate in patients of age≥10 years old, with radical resection, and preradiotherapeutical KPS≥80 was 73.7% , 82.4% , and 73.1% , respectively. And the event free survival rate in the three groups was 68.4%, 76.5%, and 68.0%, respectively. While, the 5-year overall survival rate in the groups of age<10 years old, with residual tumor, and KPS<80 was 40.1%, 35.3%, and 12.5%, respectively. And disease free survival rate was 30.8%, 26.8%, and 0%, respectively. Whereas gender, radiation source, chemotherapy,and the interval between surgery and radiotherapy did not affect prognosis. Multi-variant analysis further con-firmed that age, the extent of resection, and preradiotherapeutical KPS were prognostic factors of medulloblastoma.CONCLUSION: The main acute complication of craniospinal irradiation was leukopenia. Age, the extent of resec-tion, and preradiotherapeutical KPS were prognostic factors of medulloblastoma. Patients of age≥10 years old,with radical resection, and preradiotherapeutical KPS≥80 had a better prognosis.