应用CTVision治疗胸腹肿瘤中呼吸运动影响的研究

发布时间：2018-10-14 11:27

【摘要】：目的放射治疗是治疗胸腹部肿瘤的一个重要手段，呼吸运动是影响胸腹部肿瘤放射治疗的主要因素之一。由于呼吸运动存在，可造成照射野扩大，照射野与肿瘤靶区的重合性差，使放射治疗的精确度受到影响。众多专家学者研究出控制呼吸运动的方法有很多，但是这些方法在临床应用上均存在或多或少的缺点。有关控制呼吸运动的方法还需继续研究。在当前情况下，应用CTVision及自行设计并制作的模拟呼吸运动模具探查呼吸运动对胸腹肿瘤影响头脚方向的形变规律，并在没有4D-CT的条件下，应用CT检测肿瘤振幅的边距（头脚方向），，为肿瘤靶区勾画及如何修正计划提供依据，同时验证治疗的精确性和正确性。材料与方法实验组应用自行设计并制作的模拟呼吸运动模具，将中心内置直径3mm钢珠、直径40mm的木球置于模具托盘上，对中心，打开电源使木球做18次/分钟，总长2cm往返运动。CT扫描该运动状态图像，层厚3mm，随机扫描4次，将图像传至计划系统，比较肿瘤位置的改变，制定治疗计划，验证，观察验证偏差值。测量PTV边缘与GTV中心剂量值，计算出剂量偏差值。病例组采集2012年3月至12月胸腹肿瘤患者共21例，每位患者在定位前在模拟定位机下测量呼吸动度并记录，定位时相同范围随机扫描2次，层厚均为5mm，将图像传至计划系统，比较肿瘤位置变化，分别根据肺癌和肝癌的特点制定治疗计划，行三维适形放疗，治疗期间定期验证，每个患者至少验证3次，观察验证偏差值。将病例组与实验组的结果相比较。结果肿瘤的实测形变径在理论最大形变径内，肿瘤可运动到理论最大形变径内的任意位置。实验组验证偏差值的均值小于呼吸动度值（t=-10.78, P=0, P㩳0.05）。病例组中f、g、h、i、j、l、n、o、p、q、r、s、t、u组患者的验证偏差值的均值均小于呼吸动度值（P㩳0.05），a、b、c、k、m组患者的组验证偏差值的均值与呼吸动度值无明显差别（P㧐0.05），e组患者由于标准差为0，不能进行统计学检验， d组患者验证偏差值的均值大于呼吸动度值（P㧐0.05）。结论1、肿瘤在呼吸运动的影响下，可在呼吸动度范围内任意位置移动。2、GTV外扩外扩15mm及外扩20mm得出计量偏差为3.705％及4.07％，两者均小于5％，说明计量偏差在可接受范围内。3、验证偏差值在呼吸运动范围值内时，无需修正治疗计划，出现验证偏差值超出呼吸运动范围值，则需修正治疗计划。4、本实验所应用设备CTVision所制定并执行的放射治疗计划准确，治疗精确。
[Abstract]:Objective radiotherapy is an important method in the treatment of chest and abdomen tumors, and respiratory movement is one of the main factors affecting radiotherapy of chest and abdomen tumors. Because of the existence of respiratory movement, the radiation field can be enlarged and the coincidence between the radiation field and the tumor target is poor, which affects the accuracy of radiotherapy. Many experts and scholars have studied many methods to control respiratory movement, but these methods have more or less shortcomings in clinical application. Methods of controlling respiratory movement need to be further studied. In the present situation, CTVision and the simulated respiratory movement mould designed and made by ourselves were used to explore the deformation of the direction of head and foot affected by respiratory movement on the chest and abdomen tumor, and without 4D-CT, the deformation of the head and foot direction of the chest and abdomen tumor was investigated. CT was used to detect the margin of tumor amplitude (head and foot direction) to provide the basis for drawing tumor target and how to revise the plan, and to verify the accuracy and correctness of the treatment. Materials and methods the experimental group used the simulated respiratory movement mould designed and made by ourselves. The center diameter 3mm steel ball and the diameter 40mm ball were placed on the mould tray. The center was turned on and the wooden ball was made 18 times per minute by turning on the power supply. The total length 2cm round-trip motion. CT scans the motion state image with a thickness of 3 mm and random scanning for 4 times. The image is transmitted to the planning system to compare the change of tumor location make the treatment plan verify and observe the deviation value. The dose deviation between the edge of PTV and the center of GTV was calculated. From March to December 2012, 21 patients with chest and abdominal tumors were collected in the case group. The respiratory motility of each patient was measured and recorded under the analogue positioning machine before localization. The same range was scanned at random twice, and the thickness of the layer was 5 mm. The images were transmitted to the planning system. According to the characteristics of lung cancer and liver cancer, the treatment plan was made and three dimensional conformal radiotherapy was performed, which was verified regularly during the treatment. Each patient was verified at least 3 times, and the deviation was observed. The results of the case group and the experimental group were compared. Results the measured deformation diameter of the tumor was within the theoretical maximum deformation diameter, and the tumor could move to any position within the theoretical maximum deformation diameter. The mean deviation value of the experimental group was less than that of the respiratory motility (tr-10.78, P0, P0. 05). In the case group, the mean value of the verification deviation of the patients with FGG and PQQ is lower than that of the respiratory motility. There is no significant difference between the mean value of the validation deviation and the respiratory motility in the), e group (P0. 05), e group is 0, so it is not possible to carry out the statistical test for the patients with P0. 05), e group because of the standard deviation is 0. 5%), and there is no significant difference between the two groups (P0. 05), e patients can not carry out statistical test because of the standard deviation is 0), and there is no significant difference in the mean value of the validation deviation between the two groups. In group d, the mean value of validation deviation was greater than that of respiratory motility (P0. 05). Conclusion 1. Under the influence of respiratory movement, tumor can move anywhere in the range of respiratory motility. 2GTV extranasal 15mm and extranasal 20mm showed that the measurement deviations were 3.705% and 4.07%, both of which were less than 50.5%. It shows that the measurement deviation is within the acceptable range. 3. When the verification deviation value is within the respiratory movement range value, there is no need to revise the treatment plan, and the verification deviation value exceeds the respiratory movement range value. The treatment plan should be revised. 4. The radiotherapy plan made and executed by CTVision is accurate and accurate.
【学位授予单位】：桂林医学院
【学位级别】：硕士
【学位授予年份】：2013
【分类号】：R730.55

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