三维适形放疗同期鞘内注射化疗后全身化疗治疗高危髓母细胞瘤

Treatment of high-risk medulloblastoma by three dimensional conformal radiotherapy and intrathecal injection followed by systemic chemotherapy

目的总结全程三维适形放疗（3DCRT）N期鞘内注射化疗后全身化疗治疗高危髓母细胞瘤（MB）的疗效。方法南方医科大学珠江医院肿瘤中心自2005年1月至2008年1月行3DCRT联合鞘内注射及全身化疗治疗已沿脑脊液播散的高危MB患者20例，其中脑脊液中找到肿瘤细胞15例，MRI发现脊髓结节状种植5例。采用3DCRT进行全脑全脊髓放疗（CSr）及局部追量，放疗同期应用阿糖胞苷、氨甲喋呤等鞘内注射，放疗后应用盐酸尼莫司汀、替莫唑胺等全身化疗，回顾性分析患者的临床资料并总结疗效。结果本组患者中位随访时间48．5个月。治疗结束3个月后患者总体完全缓解（CR）18例（90．0％），部分缓解（PR）1例（5．0％），稳定（SD）1例（5．0％）；4例治疗失败死亡，1例局部复发，3例脊髓种植进展。患者中位生存时间53个月，3年总生存率（OS）和3年无病生存率（DFS）分别为80．0％、75．5％。不良反应主要为血液、消化系统的毒性反应．未出现Ⅳ度骨髓抑制。结论全程3DCRT同期鞘内注射化疗后全身化疗治疗高危MB安全、有效，预后好。

Objective To summarize the clinical efficacy of three dimensional conformal radiotherapy with concomitant intrathecal injection followed by systemic chemotherapy in the treatment of high-risk medulloblastoma （MB）. Methods The clinical data of 20 patients with high-risk MB, admitted to our hospital from January 2005 to January 2008 and certified postoperatively by pathological examination, were retrospectively analyzed in our study; 15 of them were found tumors in the cerebrospinal fluid and MRI indicated 5 were with nodular cultivation in the spinal cord. Three-dimensional conformal radiation therapy was done for all the patients with the same techniques： 28-36 Gy to the whole cranialspinal axis followed by a boost of 18 Gy. All the patients received intrathecal injection with cytarabine and amethopterin concomitantly followed by systemic chemotherapy with nimustine and temozolomide. The treatment efficacy was concluded. Results The mean follow-up was 48.5 months. Three months after treatment, the complete remission （CR） was achieved in 18 （90.0%）, and partial remission in 1 （5.0%）, and stabilization in 1 （5.0%）. Four patients were failed of treatment and died; 1 had recurrence in the region, and 3 had spinal cord planting progress. The median survival time was 53 months; and 3-y overall survival and 3-y disease-free survival were 80.0% and 75.5%, respectively. The major side effects occurred in hematological system and digestive system. No grade IV bone marrow suppression was noted. Conclusion Three-dimensional conformal radiotherapy and intrathecal injection followed by systemic chemotherapy for high-risk MB is safe and feasible, enjoying good prognosis.