鼻咽癌根治性放疗患者重新制定计划时机的研究  

Study on the timing of replanning in patients with radical radiotherapy for nasopharyngeal carcinoma

作　　者：张勇乾[1] 何丽[1] 马文华[1] 薄常文 徐慧[1] 王洪敏[1] 安永辉[2] ZHANG Yongqian;HE Li;MA Wenhua;BO Changwen;XU Hui;WANG Hongmin;AN Yonghui(Department of Oncology,the First Hospital of Hebei Medical University,Shijiazhuang 050031,China)

机构地区：[1]河北医科大学第一医院肿瘤科,河北石家庄050031 [2]河北医科大学第一医院放射科,050031

出　　处：《临床肿瘤学杂志》2021年第1期61-66,共6页Chinese Clinical Oncology

基　　金：河北省医学科学研究重点课题计划项目(20180229)。

摘　　要：目的通过观察鼻咽癌放疗中靶区和危及器官的体积、剂量变化情况,明确是否需重新制定放疗计划及其时机。方法选取15例接受调强放射治疗的鼻咽癌患者,在治疗期间,每周行螺旋CT扫描,取得CT图像,在新获取的CT上勾画靶区及危及器官,观察其体积的变化情况,并将放疗前的计划复制到各CT上,得到模拟计划,对比初始计划与模拟计划的剂量学差异。结果在放疗第4至6周时,放疗靶区受照射剂量明显降低,危及器官受照射剂量明显增加。在放疗的第6周,与放疗初始时相比,计划靶区(PTV)及左、右两侧腮腺体积分别缩小了7.08%、30.30%和26.25%;pGTV的D 95、D 98、D 100分别降低了3.46%、3.04%和6.81%;PTV的D 95、D 98、D 100分别降低了5.19%、9.99%和12.19%;左侧和右侧腮腺的V 30分别升高33.72%和26.60%,D mean分别升高27.10%和31.89%,脊髓最大剂量升高6.73%。结论鼻咽癌患者在放疗中,靶区和腮腺体积有所缩小,出现靶区剂量降低和危及器官剂量增加,建议在放疗的第5周前重新定位做计划,以减轻其影响。Objective To determine the necessity and appropriate timing of replan in the process of intensity-modulated radiotherapy(IMRT)in patients with nasopharyngeal carcinoma(NPC)by evaluating anatomic and dosimetric changes of target volumes and organs at risk(OARs).Methods A total of 15 patients were enrolled in this study.Weekly CTs were used to assess the anatomic changes.Hybrid plans were generated by copying the initial plans to CTs acquired during treatment.The dosimetric differences between the initial plans and the hybrid plans were compared.Results At the 4th to 6th week of radiotherapy,a dose reduction in the target volumes and an increase in the dose of OARs were observed.At the 6th week of radiotherapy,comparing with the initial plan of radiotherapy,the volume of PTV and the left and right parotid glands decreased by 7.08%,30.30%and 26.25%,respectively,and D 95,D 98,and D 100 of pGTV decreased by 3.46%,3.04%and 6.81%,respectively.D 95,D 98,D 100 of PTV decreased by 5.19%,9.99%and 12.19%,respectively,while V 30 of the left and right parotid gland increased by 33.72%and 26.60%,D mean increased by 27.10%and 31.89%,and the maximum dose of the spinal cord increased by 6.73%.Conclusion During IMRT of patients with NPC,a reduction of volumes of target and OAR was observed,and resulted in a dose reduction in the target volumes and an increase in the dose of OARs.It is recommended to replan before the 5th week of radiotherapy to mitigate its effects.

关 键 词：鼻咽癌 调强放射治疗 再次计划 剂量学 

分 类 号：R739.6[医药卫生—肿瘤]