Proton versus photon radiotherapy for common pediatric brain tumors: Comparison of models of dose characteristics and their relationship to cognitive function
Proton versus photon radiotherapy for common pediatric brain tumors: Comparison of models of dose characteristics and their relationship to cognitive function
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DOI：
10.1002/pbc.21530
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发表时间：
2008-07-01
影响因子：
3.2
通讯作者：
Oelfke, Uwe
中科院分区：
文献类型：
--
作者：
Merchant, Thomas E.;Hua, Chia-Ho;Oelfke, Uwe
背景为了确定质子放射治疗是否比光子放射治疗具有临床优势，我们使用四种儿童脑肿瘤患者的数据对两者对临界正常组织体积的剂量特征进行了建模。程序.采集40例患者的三维成像和治疗计划数据，包括靶向肿瘤和正常组织轮廓，其中视神经胶质瘤（OPG）、颅咽管瘤（CR）、幕下室管膜瘤（EP）或髓母细胞瘤（MB）各10例。收集每例患者全脑、颞叶、耳蜗和下丘脑的剂量体积数据。使用剂量-认知效应模型，基于治疗方式（质子与光子）对数据进行平均和比较。结果估计超过5年。结果相对较小的临界正常组织体积，如耳蜗和下丘脑，当不邻近原发性肿瘤体积时，可免于辐射暴露。较大的正常组织体积，如幕上脑或颞叶，接受的低剂量和中等剂量较少。当应用于辐射剂量-认知效应的纵向模型时，这些差异导致MB和CR患者的IQ评分以及OPG患者的学术阅读评分具有临床意义的较高。质子和光子剂量分布之间的极端差异排除了对EP患者进行有意义的质子和光子比较。结论.总体剂量分布的差异（如认知功能变化建模所示）表明，降低低闭合体积或平均剂量对MB、CR和OPC儿童具有长期临床优势。
Background. To determine whether proton radiotherapy has clinical advantages over photon radiotherapy, we modeled the dose characteristics of both to critical normal tissue volumes using data from patients with four types of childhood brain tumors. Procedures. Three-dimensional imaging and treatment planning data, including targeted tumor and normal tissues contours, were acquired for 40 patients, 10 each with optic pathway glioma (OPG), craniopharyngioma (CR), infratentorial ependymoma (EP), or medulloblastoma (MB). Dose-volume data were collected for the entire brain, temporal lobes, cochlea, and hypothalamus from each patient. The data were averaged and compared based on treatment modality (protons vs. photons) using dose-cognitive effects models. Outcomes were estimated over 5 years. Results. Relatively small critical normal tissue volumes such as the cochlea and hypothalamus may be spared from radiation exposure when not adjacent to the primary tumor volume. Larger normal tissue volumes such as the supratentorial brain or temporal lobes receive less of the low and intermediate doses. When applied to longitudinal models of radiation dose-cognitive effects, these differences resulted in clinically significant higher IQ scores for patients with MB and CR and academic reading scores in patients with OPG. Extreme differences between proton and photon dose distributions precluded meaningful comparison of protons and photons for patients with EP. Conclusions. Differences in the overall dose distributions, as indicated by modeling changes in cognitive function, showed that a reduction in the lower-close volumes or mean dose would have long-term, clinical advantages for children with MB, CR, and OPC.