【摘要】 目的:分析在食管癌摆位中利用模拟机图像匹配前后摆位误差的变化,并探讨由此造成的剂量学变化方法:利用Varian Acuity 8.6模拟机的图像匹配功能分别得出18例食管癌患者在左右(X轴)、头脚(Y轴)及前后(Z轴)三个方向上的摆位误差并依据所得误差对患者进行位置调整,得出调整后的摆位误差;在治疗计划系统中分别模拟出调整前后的治疗计划(计划2、计划3),并与原始计划(计划1)相比较结果:计划3中的PTV、CTV、GTV平均剂量高于计划2但由于摆位误差的存在低于计划1;计划1中无患者脊髓最大受量超过4500cGy而计划2、3中分别有2例患者脊髓最大受量超过4500cGy;在三类计划中计划2心脏V50、心脏和全肺平均剂量最高,全肺V20值最低。结论:摆位误差降低了靶区平均剂量,造成了危机器官(OARs)剂量升高;应用模拟机匹配后较匹配前提高了靶区平均剂量,降低了部分危机器官剂量,但脊髓最大受量、全肺V20有所上升。更多还原

【Abstract】 Objective: To analyze changes of setup errors before and after using matching function of simulator for esophageal carcinoma, then discuss dosimetric changes caused by setup errors. Methods: Setup errors of 18 patients with esophageal carcinoma in the left-right, superior-inferior and anterior-posterior directions were obtained by using function of Varian Acuity8.6 simulator, and patients’ position was adjusted according to setup errors. After adjustment new setup errors were recorded, then their corresponding plans(plan2, plan3) were simulated in the Treatment Plan System. Meanwhile, they were compared to original plan (plan1). Results: The mean dose of PTV, CTV, GTV in plan3 was higher than plan2, but was lower than plan1 due to setup errors. In plan1, no patient had maximum dose of spinal cord over 4500cGy; While in plan2 and plan3 there were 2 patients had the spinal cord dose more than 4500cGy. In plan2, the heart V50, the mean dose of heart and lungs was highest and the lung V20 was lowest. Conclusions: The mean dose of target volume decreased and dose of Organs At Risk (OARs) increased due to setup errors. After matching the mean dose of target volume increased and the dose of partial OARs decreased than before matching, but the maximum dose of spinal cord and lungs V20 increased.更多还原