Department of Radiation Oncology, The First Affiliated Hospital of Wenzhou Medical College, China.
Radiother Oncol. 2011 Jan;98(1):23-7. doi: 10.1016/j.radonc.2010.10.009. Epub 2010 Oct 30.
Anatomic changing frequently occurred during fractionated radiotherapy. The aims of this study were to model the potential benefit of adaptive IMRT replanning during fractionated radiotherapy and its potential advantage over clinical outcome in patients with nasopharyngeal carcinoma.
Thirty-three patients with repeat CT imaging and replanning were retrospectively analyzed. 66 case-matched control patients without replanning were identified by matching for AJCC stage, gender, and age. Hybrid IMRT plans were generated to evaluate the dosimetric changing. Mann-Whitney-Wilcoxon tests were used to evaluate the effect of replanning on volumetric and dosimetric outcomes within individuals. Kaplan-Meier estimators were used to estimate the survival function of patients with or without replanning.
The mean volume of the ipsilateral and contralateral parotid glands decreased during the treatment. The hybrid IMRT plans showed decreased doses to target volumes and increased doses to normal structures in replanning. The clinical outcome comparison indicated that the IMRT replanning improved the 3 years local progression-free survival for patients who had AJCC staged more than T(3) (T(3,4)N(x)) and ease the late effects for patients who had large lymph nodes (AJCC stage T(x)N(2,3)).
Repeat CT imaging and IMRT replanning were recommendatory for specific nasopharyngeal carcinoma patients.
在分次放射治疗过程中，解剖结构经常发生变化。本研究旨在建立模型，评估在分次放射治疗中进行自适应调强放疗（IMRT）计划重订的潜在获益，以及它对鼻咽癌患者临床结局的潜在优势。
回顾性分析了 33 例接受重复 CT 成像和计划重订的患者。通过匹配 AJCC 分期、性别和年龄，确定了 66 例无计划重订的病例匹配对照患者。生成混合 IMRT 计划，以评估剂量变化。采用曼-惠特尼-威尔科克森检验评估个体内重订对体积和剂量学结果的影响。采用 Kaplan-Meier 估计法估计有无计划重订患者的生存函数。
在治疗过程中，同侧和对侧腮腺的平均体积减小。计划重订后的混合 IMRT 计划显示靶区体积的剂量降低，正常结构的剂量增加。临床结局比较表明，对于 AJCC 分期高于 T（3）（T（3，4）N（x））的患者，IMRT 计划重订改善了 3 年局部无进展生存率，并缓解了大淋巴结（AJCC 分期 T（x）N（2，3））患者的晚期效应。
对于特定的鼻咽癌患者，推荐进行重复 CT 成像和 IMRT 计划重订。
