鼻咽癌调强放疗每周腮腺动态变化的临床分析  

Clinical analysis for weekly changes of parotid glands during intensity-modulated radiotherapy for nasopharyngeal carcinoma patients

作　　者：魏双[1] 郝俊芳[1] 杨新华[1] 卢洁[1] 尚东平[1] 曹秀娟[1] 

机构地区：[1]山东省肿瘤防治研究院放疗科,山东济南250117

出　　处：《中国癌症杂志》2013年第3期211-217,共7页China Oncology

摘　　要：背景与目的：鼻咽癌调强放疗过程中腮腺体积、剂量等将发生变化，但每周变化情况及最显著变化时刻，文献报道各不相同，不能指导临床。本研究探讨鼻咽癌患者放疗过程中每周腮腺位移、体积、剂量、c2水平直径变化及与放疗后口腔干燥程度的关系，指导临床修改放疗计划的合适时机。方法：选择10例行调强放疗的鼻咽癌患者，放疗1～5周，每周于大孔径CT下平扫，并与计划CT融合，逐层勾画腮腺，分析每周腮腺位移、体积、剂量及C2水平直径变化，并在放疗结束后随访3个月患者口干程度。结果：放疗5周后左、右侧腮腺体积分别较放疗前缩小29％～44．9％、28％～57．1％，腮腺中心点侧向位移分别为-4．1—9．2mm、-2．8-9．8mm，剂量分别为放疗前的148．3％-259．4％、198．1％～274．7％。C2水平外轮廓直径出现逐渐减小趋势。左侧腮腺体积、侧向位移及剂量均于第3周变化最显著，右侧腮腺体积、侧向位移及剂量分别于第4周、第2周、第3周变化最显著。C2水平直径变化与口干程度显著相关。结论：两侧腮腺受照剂量均于第3周变化最显著，此时修改放疗计划有一定临床获益。Background and purpose： It is reported that the volume and dosimetry ofparotid glands would change, however, the weekly changes of them and when to attain the most distinguished moment are controversial and the results can not effectively guide the clinical practice. The study aimed to analysis weekly volume, displacement, dimension of C2 and dosimetric changes of parotid glands during intensity-modulated radiotherapy for nasopharyngeal carcinoma patients, and the relationship between dimension of C2 and xerostomia in order to guide the best time for altering the radiation planning. Methods： Ten nasopharyngeal patients receiving intensity-modulated radiotherapy had repeat CT scanning at weeks 1, 2, 3, 4 and 5 during radiation. All repeat CTs were fused with the planned CT and contoured the parotid glands. Weekly volume, displacement, dimension of C2 and dosimetric changes of parotid glands were calculated and the xerostomia of patients was followed after 3 months of radiotherapy. Results： In the fifth week of radiotherapy, the volume of left and right parotid glands decreased by 29%-44.9% and 28%-57.1%, the lateral displacement of centers of both parotid glands were -4.1 to 9.2 mm and -2.8 to 9.8 mm, and the dosimetry increased to 148.3%-259.4% and 198.1%-274.7%, respectively. The dimension of C2 decreased gradually. We can detected the most distinguished changes of volume, displacement and dosimetry for the left parotid gland in the third week, however their most distinguished changes for the right parotid gland were in the third week, second week and fourth week respectively. The dimensional change of C2 was correlated with post radiotherapy xerostomia significantly. Conclusion： The most distinguished changes of dosimetric changes for both parotid glands occur in the third week, and it is the best time to modify the radiotherapy plan.

关 键 词：鼻咽癌 调强放疗 腮腺变化 口腔干燥症 

分 类 号：R739.87[医药卫生—肿瘤]