PDF(Pubmed)
Abstract：
The current Radiotherapy (RT) technology still inevitably irradiated normal brain tissue, causing implicit radiation-induced injury. This study investigates the precise localization and the corresponding radiation dosage of brain regions susceptible to damage in nasopharyngeal carcinoma (NPC) patients following RT. Utilizing the Advanced Normalization Tools (ANTs) package, a computed tomography (CT) brain template was created in the standard Montreal Neurological Institute (MNI) space, based on 803 Chinese NPC patients (T0~T4) who underwent RT. With this template, all patients\' CT and RTdose data were registered to the MNI space, and the RTdose distribution characteristics in normal brain tissues were compared for NPC patients treated with Intensity-modulated radiotherapy (IMRT) or Volumetric Modulated Arc Therapy (VMAT), with patients\' age and gender as covariates. Analysis of the average dosages indicated that certain areas within the Limbic, Temporal, and Posterior Lobes, the Brainstem, and the Cerebellum Posterior Lobe were exposed to doses exceeding 50 Gy. Inter-group analysis revealed that IMRT delivered higher doses than VMAT to brain regions anterior to the nasopharyngeal tumor, whereas VMAT affected the posterior regions more. Interestingly, VMAT showed a drawback in preserving the normal brain tissues for T4-stage patients. This revealed that the two treatment modalities have unique characteristics in preserving normal brain tissue, each with advantages. With better localization precision, the created CT brain template in MNI space may be beneficial for NPC patients\' toxicity and dosimetric analyses.
摘要：
目前的放射治疗(RT)技术仍不可避免地照射正常脑组织,引起内隐放射损伤。这项研究调查了放疗后鼻咽癌（NPC）患者易受损伤的脑区的精确定位和相应的辐射剂量。利用高级标准化工具(ANT)包，在标准的蒙特利尔神经研究所（MNI）空间中创建了计算机断层扫描（CT）脑模板，根据803例接受RT的中国NPC患者（T0〜T4）。有了这个模板，所有患者的CT和RTD剂量数据都被登记到MNI空间，比较了接受调强放疗（IMRT）或体积调制电弧治疗（VMAT）的NPC患者在正常脑组织中的RTF剂量分布特征，以患者的年龄和性别为协变量。平均剂量分析表明，边缘区域内的某些区域，时间,和后角，脑干，小脑后叶暴露于超过50Gy的剂量。组间分析显示，IMRT比VMAT向鼻咽肿瘤前的脑区提供更高的剂量，而VMAT对后部区域的影响更大。有趣的是,VMAT在保留T4期患者的正常脑组织方面表现出缺点。这表明两种治疗方式在保存正常脑组织方面具有独特的特点，每个人都有优势。具有更好的定位精度，在MNI空间创建的CT脑模板可能对NPC患者的毒性和剂量学分析有益.
