Department of Radiation Oncology, University of Florida College of Medicine, Jacksonville, Florida.
Department of Radiation Oncology, University of Florida College of Medicine, Jacksonville, Florida.
Int J Radiat Oncol Biol Phys. 2019 May 1;104(1):149-156. doi: 10.1016/j.ijrobp.2019.01.078. Epub 2019 Jan 23.
Dosimetric studies show that proton therapy can reduce the low/intermediate radiation dose to uninvolved tissue in children with low-grade glioma (LGG). For this reason, LGG is the fourth most common pediatric tumor treated with proton therapy, yet clinical outcome data on efficacy and toxicity are limited.
We reviewed the medical records of 174 children (≤21 years old) with nonmetastatic LGG enrolled on a prospective protocol and treated with proton therapy between 2007 and 2017. We assessed clinical outcomes and toxicity and analyzed patient, tumor, and treatment-related variables.
The median age was 10.2 years (range, 2-21). Fifty-eight percent of tumors were World Health Organization grade 1 and 30% were grade 2; 12% were diagnosed on imaging characteristics alone. The most common histology was pilocytic astrocytoma (47%). The most common tumor subsites were diencephalon/optic pathway (52%), caudal brainstem (16%), and cerebellum (13%). Forty-two percent received chemotherapy before radiation therapy. The median follow-up was 4.4 years. The 5-year actuarial rates of local control, progression-free survival, and overall survival were 85% (95% confidence interval [CI], 78%-90%), 84% (95% CI, 77%-89%), and 92% (95% CI, 85%-95%), respectively. On univariate analysis, brainstem/spinal cord tumor location (62% vs 90% elsewhere) and dose <54 GyRBE (67% vs 91% for 54 GyRBE) were associated with inferior local control (P < .01 for both). Twenty-two patients (12.6%) experienced acute nausea or vomiting requiring ondansetron; 2 patients (1.1%) required corticosteroids. Serious toxicities (4% of patients) included brainstem necrosis requiring corticosteroids (n = 2), symptomatic vasculopathy (n = 2), radiation retinopathy (n = 1), epilepsy (n = 1), and death from radiation-induced high-grade glioma (n = 1). Thirty-nine patients (22%) developed new-onset central hormone deficiency. Pseudoprogression was observed in 32.1%.
Compared with modern photon series, proton therapy reduces the radiation dose to developing brain tissue, diminishing acute toxicities without compromising disease control.
剂量学研究表明，质子治疗可降低低级别胶质瘤（LGG）儿童未受累组织的低/中剂量辐射。由于这个原因，LGG 是第四种最常见的采用质子治疗的儿科肿瘤，但关于疗效和毒性的临床结果数据有限。
我们回顾了 2007 年至 2017 年间，174 名患有非转移性 LGG 的≤21 岁儿童的前瞻性方案治疗的质子治疗记录。我们评估了临床结果和毒性，并分析了患者、肿瘤和治疗相关变量。
中位年龄为 10.2 岁（范围：2-21 岁）。58%的肿瘤为世界卫生组织 1 级，30%为 2 级；12%的肿瘤仅根据影像学特征诊断。最常见的组织学类型为毛细胞型星形细胞瘤（47%）。最常见的肿瘤部位为间脑/视路（52%）、颅尾脑干（16%）和小脑（13%）。42%的患者在放疗前接受了化疗。中位随访时间为 4.4 年。5 年局部控制、无进展生存率和总生存率的 actuarial 率分别为 85%（95%置信区间[CI]：78%-90%）、84%（95% CI：77%-89%）和 92%（95% CI：85%-95%）。单因素分析显示，脑干/脊髓肿瘤部位（62%与其他部位 90%）和剂量＜54 GyRBE（67%与 54 GyRBE 91%）与局部控制不良相关（均 P＜0.01）。22 名患者（12.6%）出现需要昂丹司琼治疗的急性恶心或呕吐；2 名患者（1.1%）需要皮质类固醇。严重毒性（占患者的 4%）包括需要皮质类固醇的脑干坏死（n=2）、症状性血管病（n=2）、放射性视网膜病变（n=1）、癫痫（n=1）和放射性高级别胶质瘤导致的死亡（n=1）。39 名患者（22%）新发中枢性激素缺乏。32.1%观察到假性进展。
与现代光子系列相比，质子治疗降低了发育中脑组织的辐射剂量，在不影响疾病控制的情况下减少了急性毒性。
