1. 前列腺癌三维适形放疗的不确定性因素分析 2. 上颌窦鳞癌术前放疗后病理反应的预后意义

【作者】 刘跃平；

【导师】 刘新帆； 李晔雄；

【作者基本信息】 中国协和医科大学 ， 肿瘤学， 2005， 博士

【摘要】 目的 研究盆腔肿瘤三维适形放疗的摆位误差大小，为盆腔肿瘤适形放疗计划设计时CTV外放PTV提供参考数据。 材料与方法 接受放疗的直肠癌病例3例和前列腺癌病例2例，均为男性，行俯卧位盆腔三维适形放疗，治疗时身下垫有孔泡沫板，热塑成型固定膜固定。每例病例连续5天照射，每次摆位时在体表固定点粘贴定位金点，加速器机头插入定位“+”字刻度板，照射正侧位治疗验证片各一张，共计摆位25次，照射治疗验证片50张。以第一次摆位片为标准，计算前后、头尾、左右方向摆位误差。 结果 分析5例病例25次摆位误差，人与人之间以及次与此之间均存在一定差别。前后方向摆位误差最大，平均值为0.98±0.68cm((?)±SD)，有9次摆位误差≥1cm，占测算次数的45％，其中2次误差≥2cm；头尾方向摆位误差为0.5～0.7±0.45cm，正位测定头尾方向误差小于侧位，分别为0.51±0.46cm和0.70±0.45cm((?)±SD)，正位和侧位分别有4次和7次摆位误差≥1cm；左右方向误差最小，为0.37±0.28cm((?)+SD)，仅1次误差≥1cm。 结论 在三维适形技术放疗盆腔肿瘤时，左右方向摆位误差最小，头尾方向居中，前后方向最大；CTV外放PTV应考虑：左右方向0.5cm，头尾方向1.0cm，前后方向1.5cm。更多还原

【Abstract】 PurposeTo investigate the spatial distribution of set-up errors for patients treated with three-dimensional (3D) conformal radiation therapy for pelvic carcinoma and to provide referential safe margins out of CTV during treatment plan design. Materials and MethodsFive patients with rectal or prostate cancers entered the study. All were treated with three-dimensional conformal radiotherapy in a prone position. Belly board was used. Thermoplastic cast was used for immobilization. Measurements were made on a daily basis setup under five consecutive treatments. During patients positioning, gold particles were placed on the skin markers, one in the lateral, and the other in the back. Portal films from two projections (one anterior-posterior and one opposite lateral) were taken after the reticule localizer was inserted to the head of accelerator. Fifty portal films from 25 setups were analyzed. The spatial distribution of set-up errors from left-right, superior-inferior and anterior-posterior directions were evaluated comparing to the first set-up films (representing the standard treatment position).ResultsThe magnitude of set-up errors from 25 positionings in 5 patients differed from patient to patient and day to day. Maximal set-up errors were inspected in the anterior-posterior direction, with a mean of 0.98±0.68 cm (X±SD), 9 of 20 measurements (45%) were > or =1 cm, and two in the 9 measurements were > or =2 cm; The set-up errors for superior-inferior were 0.5-0.7±0.45 cm (X±SD), and the average magnitude from anterior-posterior films was smaller than that from opposite lateral films, 0.51±0.46 cm and 0.70±0.45 cm, respectively. There were 4 and 7 times of > or =1 cm superior-inferior displacements measured from anterior-posterior films and lateral films respectively; the更多还原