Deutsch M, Thomas P R, Krischer J, Boyett J M, Albright L, Aronin P, Langston J, Allen J C, Packer R J, Linggood R, Mulhern R, Stanley P, Stehbens J A, Duffner P, Kun L, Rorke L, Cherlow J, Freidman H, Finlay J L, Vietti T
University of Pittsburgh Medical Center, Pa., USA.
Pediatr Neurosurg. 1996;24(4):167-176; discussion 176-7. doi: 10.1159/000121042.
To determine in a prospective randomized trial the effect on survival, progression-free survival, and patterns of relapse of a decrease in the neuraxis radiation dose from 3,600 cGy in 20 fractions to 2,340 cGy in 13 fractions in patients with newly diagnosed medulloblastoma between 3 and 21 years of age with low T stage (T1, T2 and T3A), minimal postoperative residual tumor, and no evidence of dissemination (M0).
Between June 1986 and November 1990, the Children's Cancer Group and the Pediatric Oncology Group randomized 126 patients in a two-arm study comparing the two different doses of neuraxis irradiation. In both arms, the posterior fossa received 5,400 cGy in 30 fractions. All patients were staged with myelography, postoperative lumbar cerebrospinal fluid cytology, and postoperative contrast-enhanced cranial computerized tomography to ensure no evidence of dissemination and no more than 1.5 cm3 residual tumor volume. Overall survival, progression-free survival, and patterns of recurrence were carefully monitored. Prospective endocrine and psychometric studies were performed to determine the benefit of decreasing the neuraxis radiation dose.
Following an interim analysis at a median time on study of 16 months, the study was closed, since a statistically significant increase was observed in the number of all relapses as well as isolated neuraxis relapses in patients randomized to the lower dose of neuraxis radiation.
In patients with newly diagnosed medulloblastoma considered to have a good prognosis on the basis of low T stage, minimal residual tumor after at least subtotal resection, and no evidence of dissemination after thorough evaluation, there is an increased risk of early relapse associated with lowering the dose of neuraxis radiation from 3,600 cGy in 20 fractions to 2,340 cGy in 13 fractions.
在一项前瞻性随机试验中，确定对于年龄在3至21岁、T分期较低（T1、T2和T3A）、术后残留肿瘤极小且无播散证据（M0）的新诊断髓母细胞瘤患者，将神经轴放疗剂量从20次分割的3600 cGy降至13次分割的2340 cGy对生存、无进展生存和复发模式的影响。
1986年6月至1990年11月期间，儿童癌症组和儿科肿瘤学组在一项双臂研究中对126例患者进行了随机分组，比较两种不同剂量的神经轴照射。在两个治疗组中，后颅窝均接受30次分割的5400 cGy照射。所有患者均通过脊髓造影、术后腰椎脑脊液细胞学检查和术后增强头颅计算机断层扫描进行分期，以确保无播散证据且残留肿瘤体积不超过1.5 cm³。对总生存、无进展生存和复发模式进行了仔细监测。进行了前瞻性内分泌和心理测量研究，以确定降低神经轴放疗剂量的益处。
在研究中位时间为16个月时进行中期分析后，该研究提前结束，因为在随机分配至较低剂量神经轴放疗的患者中，观察到所有复发以及孤立性神经轴复发的数量在统计学上显著增加。
对于基于低T分期、至少次全切除术后残留肿瘤极小且经过全面评估无播散证据而被认为预后良好的新诊断髓母细胞瘤患者，将神经轴放疗剂量从20次分割的3600 cGy降至13次分割的2340 cGy会增加早期复发风险。
