PURPOSE To estimate the rate and magnitude of neurologic symptom change during radiation therapy (RT) and impact of symptom change on survival outcomes in patients with diffuse intrinsic pontine glioma (DIPG). METHODS From 2006 to 2014, 108 patients with newly diagnosed DIPG were treated with conventionally fractionated radiation therapy (RT) to 54 Gy (median) at our institution. The presence and severity of neurologic symptoms related to cranial neuropathy (CN) and cerebellar (CB) and long-tract (LT) signs was reviewed before and weekly during RT for each patient. The rate and magnitude of change for each symptom category was evaluated according to accumulated RT dose. The impact of clinical factors and radiation dose-volume parameters was determined using Cox proportional hazards models. RESULTS Median dose to first sign of symptomatic improvement was 16.2 Gy (CN), 19.8 Gy (LT) and 21.6 Gy (CB). Most patients showed an improvement by 20 Gy. Larger uninvolved brainstem volume, alone or normalized to total brain (TB) or posterior fossa volume (PF), was associated with shorter time to LT sign improvement (P = 0.044, P = 0.033, and P = 0.05, respectively). Patients with any improvement in CN experienced significantly, yet modestly, prolonged progression-free survival (PFS) and overall survival (OS) (P = 0.002 and P = 0.008, respectively). Tumor volume, with or without normalization to TB or PF, was not significantly associated with PFS or OS. CONCLUSIONS Low cumulative RT doses resulted in neurologic improvement in most patients with DIPG. The volume of brainstem spared by tumor influenced time to symptomatic improvement. Neurologic improvement during RT was associated with superior survival.

中文翻译：

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弥漫性桥脑神经胶质瘤保形放射治疗期间神经系统症状的放射剂量反应。

目的评估弥散性桥脑神经胶质瘤（DIPG）患者在放射治疗（RT）期间神经系统症状变化的速率和幅度以及症状变化对生存结局的影响。方法2006年至2014年，我们机构对108例新诊断为DIPG的患者进行了常规分级放射治疗（RT）至54 Gy（中位数）。在RT之前和每周对每位患者进行与颅神经病（CN），小脑（CB）和长途（LT）体征相关的神经系统症状的存在和严重程度的回顾。根据累积的RT剂量评估每种症状类别的变化率和幅度。使用Cox比例风险模型确定临床因素和辐射剂量参数的影响。结果症状改善的第一个迹象的中位剂量为16.2 Gy（CN），19.8 Gy（LT）和21.6 Gy（CB）。大多数患者表现出20 Gy的改善。单独或标准化为总脑（TB）或后颅窝体积（PF）的较大的未累及的脑干量与LT征象改善的时间较短相关（分别为P = 0.044，P = 0.033和P = 0.05）。CN改善的患者经历了显着而适度的无进展生存期（PFS）和总体生存期（OS）（分别为P = 0.002和P = 0.008）。不论是否将TB或PF归一化，肿瘤体积与PFS或OS均无显着相关性。结论低累积RT剂量可使大多数DIPG患者的神经功能得到改善。肿瘤遗留的脑干量影响症状改善的时间。