Bauman G S, Sneed P K, Wara W M, Stalpers L J, Chang S M, McDermott M W, Gutin P H, Larson D A
Department of Radiation Oncology, London Regional Cancer Center, Ontario, Canada.
Int J Radiat Oncol Biol Phys. 1996 Sep 1;36(2):433-41. doi: 10.1016/s0360-3016(96)00315-x.
Primary central nervous system (CNS) tumors are seldom reirradiated due to toxicity concerns and sparse clinical data regarding efficacy.
We retrospectively reviewed 34 patients with primary brain tumors retreated with fractionated external beam irradiation at the University of California, San Francisco from 1977-1993. Tumors included 15 medulloblastomas, 10 high-grade gliomas, 7 low-grade gliomas, and 2 meningiomas.
Initial course of radiation was radical in intent for all patients. Median age at initial diagnosis was 19.8 years (range: 3.6-67). Median interval between radiation courses was 16.3 months (range: 3.8-166). Median Karnofsky Performance Status (KPS) prior to reirradiation was 80 (range: 40-100). Reirradiation volumes overlapped previous treatment in 30 patients and were nonoverlapping in 4 patients. Fractionation schemes used were hyperfractionated in 17, conventionally fractionated in 9, and hypofractionated in 8. Cumulative maximum overlap dose within the CNS ranged from 43.2-111 Gy (median: 79.7 Gy). Retreatment was completed as planned in 27 out of 34 patients and modified or aborted in 7 (four tumor progression on retreatment, three patient request). As measured from the time of retreatment median progression free and overall survival was 3.3 and 8.3 months. Clinical and radiographic indices were stabilized or improved in about half of patients evaluable at a median of 3 months postretreatment. Complications (early or late) potentially attributable to retreatment were noted in 10 of 34 (29%) of patients. Overt necrosis was noted in 3 of 34 (9%) of patients and the actuarial risk of necrosis was 22% at 1 year following retreatment.
Reirradiation of primary central nervous system tumors was associated with only modest palliative and survival benefits in this retrospective review. Difficulties separating toxicity due to retreatment vs. tumor progression and limited patient survival following retreatment preclude definite conclusions regarding the safety of this practice.
由于毒性问题以及关于疗效的临床数据稀少，原发性中枢神经系统（CNS）肿瘤很少进行再次放疗。
我们回顾性分析了1977年至1993年在加利福尼亚大学旧金山分校接受分次外照射治疗的34例原发性脑肿瘤患者。肿瘤包括15例髓母细胞瘤、10例高级别胶质瘤、7例低级别胶质瘤和2例脑膜瘤。
所有患者初始放疗疗程的目的均为根治性。初始诊断时的中位年龄为19.8岁（范围：3.6 - 67岁）。两次放疗疗程之间的中位间隔时间为16.3个月（范围：3.8 - 166个月）。再次放疗前的中位卡氏功能状态评分（KPS）为80（范围：40 - 100）。30例患者再次放疗的体积与先前治疗区域重叠，4例患者不重叠。采用的分割方案中，17例为超分割，9例为常规分割，8例为低分割。中枢神经系统内累积最大重叠剂量范围为43.2 - 111 Gy（中位值：79.7 Gy）。34例患者中有27例按计划完成了再次治疗，7例进行了调整或终止治疗（4例在再次治疗时肿瘤进展，3例因患者要求）。从再次治疗时开始计算，中位无进展生存期和总生存期分别为3.3个月和8.3个月。约一半可评估的患者在再次治疗后中位3个月时临床和影像学指标稳定或改善。34例患者中有10例（29%）出现了可能归因于再次治疗的并发症（早期或晚期）。34例患者中有3例（9%）出现明显坏死，再次治疗后1年坏死的精算风险为22%。
在这项回顾性研究中，原发性中枢神经系统肿瘤的再次放疗仅带来适度的姑息和生存益处。难以区分再次治疗导致的毒性与肿瘤进展，且再次治疗后患者生存期有限，因此无法就这种做法的安全性得出明确结论。
