Symptomatic Outcomes in Relation to Tumor Expansion After Fractionated Stereotactic Radiation Therapy for Vestibular Schwannomas: Single-Institutional Long-Term Experience
Symptomatic Outcomes in Relation to Tumor Expansion After Fractionated Stereotactic Radiation Therapy for Vestibular Schwannomas: Single-Institutional Long-Term Experience
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DOI：
10.1016/j.ijrobp.2012.05.003
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发表时间：
2013-02-01
影响因子：
7
通讯作者：
Shirato, Hiroki
中科院分区：
文献类型：
--
作者：
Aoyama, Hidefumi;Onodera, Shunsuke;Shirato, Hiroki
目的：常规分割立体定向放射治疗(SRT)后肿瘤的短暂扩张对症状转归的影响尚不清楚。方法和材料：本研究纳入201例连续接受立体定向放射治疗的前庭神经鞘瘤患者。194例(97%)患者采用常规分割方案，142例(71%)患者接受总剂量50Gy.结果：最大直径<9 mm者13例，10~19 mm者79例，20~29 mm者87例，30 mm以上者22例。肿瘤大小在20 mm或更大时与听力丧失和三叉神经病显著相关。术后肿瘤扩张42例(21%)。肿瘤直径小于或等于9 mm、10~19 mm、20~29 mm和大于30 mm的患者中，肿块扩大率分别为0%、11.4%、25.6%和50%。肿瘤扩大与需要分流的脑积水(P=.004)、可用听力丧失(P=.0064)以及面部(P<；.0001)和三叉神经(P<；.0001)功能恶化的风险增加显著相关。在这42名患者中，有29名患者观察到了自发的肿瘤缩小，大多数在扩张后的2年内，除听力外的大多数恶化症状在肿瘤缩小后消失。因此，仅有5%的患者需要保留手术以缓解症状。结论：分割的SRT甚至可以安全地应用于中到大型(<20 mm)的肿瘤。然而，需要更多地了解SRT后患者的风险和后果，包括短暂的症状恶化，以及扩大的时间跨度，以避免不必要的手术干预。(C)2013年爱思唯尔公司。
Purpose: The effect of transient tumor expansion after conventionally fractionated stereotactic radiation therapy (SRT) on the symptomatic outcomes is not well-known.Methods and Materials: This study enrolled 201 consecutive patients who received SRT for vestibular schwannoma. A conventional fractionation schedule was applied in 194 patients (97%), and 142 (71%) received a total dose of 50 Gy. The median follow-up time was 72 months.Results: The maximum diameter was 9 mm or less in 13 patients, 10-19 mm in 79 patients, 20-29 mm in 87 patients, and 30 mm or greater in 22 patients. At presentation, tumor size of 20 mm or greater was significantly associated with loss of serviceable hearing and trigeminal neuropathy. After SRT, tumor expansion was observed in 42 patients (21%). By tumor size, tumor expansion was observed in 0%, 11.4%, 25.6%, and 50% of patients with tumors of 9 mm or less, 10-19 mm, 20-29 mm, and 30 mm or greater, respectively, in diameter. The tumor expansion was significantly associated with an increased risk of hydrocephalus requiring shunt placement (P = .004), loss of serviceable hearing (P = .0064), and worsening of facial (P < .0001) and trigeminal nerve (P < .0001) functions. Spontaneous tumor shrinkage was observed in 29 of those 42 patients, mostly within 2 years after the expansion, and the majority of the worsened symptoms except for hearing resolved once the tumor had shrunk. As a result, salvage surgical resection for symptomatic relief was required in only 5% of patients.Conclusions: Fractionated SRT could be safely applied even for medium-to large-sized (>= 20 mm) tumors. However, greater knowledge of the risks and consequences, including transient symptomatic worsening, and the time span of expansion will be required for the follow-up of patients after SRT to avoid unnecessary surgical intervention. (C) 2013 Elsevier Inc.