放疗在髓母细胞瘤治疗中的作用

背景与目的:髓母细胞瘤(medulloblastoma,MB)起源于小脑外颗粒层的原始神经上皮细胞,是一类恶性程度高的肿瘤,针对于此肿瘤的研究极少。本文分析其临床特点、综合治疗的效果和影响预后的因素,并探讨其治疗策略。方法:收集了1991年1月～2008年4月于中山大学肿瘤防治中心诊治的MB 43例,比较有、无放疗对其总生存率及无进展生存率的影响。同时分析探讨影响MB患者预后的不良因素;采用Kaplan-Meier法计算全组生存率,组间比较用Log-rank检验。结果:43例MB患者中,36例接受放疗,其中26例行全中枢放疗。全部患者均行手术治疗,其中29例肿块完全切除,14例部分切除。19例行化疗。单因素分析显示,放疗剂量≥50Gy组的总生存率及无进展生存率均有明显提高,P值分别为0.018及0.027。此外,T晚期、手术残留为影响预后的因素。结论:接受放疗的MB患者总生存率及无进展生存率是有升高趋势的。足量的放疗剂量(≥50Gy)可改善预后,延长生命。需对MB行全中枢放疗,其剂量无公认标准。MB不良预后因素有:无放疗、T晚期(T3、T4期)及手术后肿瘤残留。

Role of radiation in the treatment of medulloblastom

BACKGROUND ＆ OBJECTIVE： Medulloblastoma, originning from the neuroepithelial eell at the external granular layer of cerebellum, is a kind of highly malignant tumor, and researches on the tmnors are rare. This study was to investigate the clinical characteristics, treatment modality and efficacy of MB, and thus to explore the treatment principle and the prognostic factors of MB. METHODS： This report analyzed 43 MB patients, who were treated in the Sun Yat-Sen University Cancer Center during the period from 1991 to 2008. We investigated the influence of overall survival （OS） and progression-free survival （PFS） by RT. Cumulative survival rates wereestimated by the Kaplan-Meier method. Prognostic factors were tested using the log- rank test. RESULTS： Of 43 MB patients, 36 cases received RT and 26 patients received craniospinal irradiation （CSI）. AI｜ cases were treated with surgery. Nineteen patientsunderwent chemotherapy. The patients who received RT with a dose of above 50Gy had a better outcome in OS and PFS than the group that did not （P = 0.018 and P = 0.027）. In univariate analysis, variables such as T stage and surgery, were all shown to have significant prognostic impact on overall survival for total subjects included in our study. CONCLUSIONS： We found a trend of an improvement in OS and PFS for those MB patients who had received RT. Sufficient RT dose （~〉50Gy） may improve prognosis and prolong survival. CSI is required in MB patients, but the dose of RT remains disputable. The prognosis is poor for patients without RT. T3 and T4 stage, and residual after surgery are negative prognostic factor for MB patients.