等效均匀剂量放射生物效应数学模型研究
发布时间：2019-02-19 15:37
【摘要】：放射治疗正呈现出以下两个主要研究方向:1.放射治疗分割剂量及治疗方案的优化改进。2.改善放射剂量在体内的分布。这两个方面都必须基于对治疗效果的准确预评价,即对肿瘤及危及器官放射生物学行为的准确判断。临床对于治疗结果的判断主要采用剂量体积直方图,而该图的技术缺陷也很明显,首先,对于统计值相同,剂量分布不同的计划,无法比较其放射生物学响应。其次,描述计划时,只能用分布图上几个参考点上的剂量来描述。最后,对于不同分割量,相同总剂量的计划无法比较。 论文在Niemierko研究的基础上,考虑了肿瘤细胞在放射治疗过程中的增殖效应,在原等效均匀剂量数学模型的基础上,加入了潜在倍增时间这一变量,改进了模型,使得不同分割剂量、不同剂量梯度分布、不同分次照射间隔时间的治疗计划之间有了比较的途径和参照,克服了剂量体积直方图的弱点。 在不同参数的变化下,通过对1995年版、1999年版及含潜在倍增时间的等效均匀剂量的变化趋势及程度的比较,确定了各个参数在这个模型中的权重和各模型之间的区别与联系、各个模型的特点及其适宜的应用领域与条件。 对40例肺部接受放射治疗患者的肺部等效均匀剂量及传统的体积剂量参数的统计对比,进一步研究了等效均匀剂量在正常组织所受放射性损伤方面评估的参考价值,并提出了研究肺部放射性损伤时的建议a值。研究结果表明等效均匀剂量可以克服不同计划图像、不同分次肺部组织生物学效应评估困难,并可以很好地预测放射性损伤,具有一定的临床应用价值。 对6例大分割剂量治疗计划与三维适形照射计划的99版及含潜在倍增时间的等效均匀剂量的对比,分析了等效均匀剂量模型在研究大分割照射、不同分次照射、不同间隔时间照射时对于肿瘤放射生物学效应的评估价值。研究表明等效均匀剂量、尤其是含潜在倍增时间的等效均匀剂量能非常敏感地反映出细胞倍增效应对于肿瘤组织放射治疗结果的影响,具有一定的临床应用价值。 论文最后提出了进一步改进等效均匀剂量数学模型的建议,考虑将潜在倍增时间转化为总放射剂量的一个函数,将正常组织修复因子融入到等效均匀剂量模型中,使得模型更加完善,能够为临床提供更准确的预测。
[Abstract]:Radiotherapy is showing the following two main research directions: 1. Optimization and improvement of fractionation dose and treatment scheme for radiotherapy. 2. To improve the distribution of radiation dose in vivo. These two aspects must be based on the accurate pre-evaluation of the therapeutic effect, that is, the accurate judgment of the radiobiological behavior of the tumor and the organ endangering it. Dose volume histogram is the main method to judge the therapeutic results in clinic, and its technical defects are also obvious. First of all, it is impossible to compare the radiobiological response for the plan with the same statistical value and different dose distribution. Second, the plan can only be described in terms of doses at several reference points on the map. Finally, the plan for the same total dose cannot be compared with different partitioning doses. On the basis of Niemierko study, the proliferation effect of tumor cells during radiotherapy was considered. On the basis of the original equivalent uniform dose mathematical model, the variable of potential doubling time was added to improve the model. The treatment plan with different dose distribution, different dose gradient distribution and different interval time of irradiation has a comparison approach and reference, which overcomes the weakness of dose volume histogram. Under the change of different parameters, the weight of each parameter in this model and the difference and relation between each model are determined by comparing the change trend and degree of the equivalent uniform dose with the 1995 edition, the 1999 edition and the potential doubling time. The characteristics of each model and its suitable application fields and conditions. The statistical comparison of the lung equivalent uniform dose and the traditional volume dose parameters of 40 patients receiving radiation therapy was carried out, and the reference value of evaluating the radiation damage to normal tissues was further studied. The suggested a value for the study of lung radiation injury is also proposed. The results show that the equivalent uniform dose can overcome the difficulty of evaluating the biological effects of lung tissue in different planning images and different grades of lung tissue, and can predict the radiation injury well, which has certain clinical application value. In this paper, we compared the 99 version of large segmented dose treatment plan with that of three-dimensional conformal radiation plan and the equivalent uniform dose with potential doubling time, and analyzed that the model of equivalent uniform dose was used to study the large segmented irradiation and the different times of irradiation. Evaluation of radiobiological effects of different intervals of irradiation on tumors. It has been shown that the effect of cell doubling effect on the radiotherapy results of tumor tissue can be reflected sensitively by the equivalent uniform dose, especially with the potential doubling time, which has certain clinical application value. At the end of the paper, some suggestions are put forward to further improve the mathematical model of equivalent uniform dose. We consider converting the potential doubling time into a function of total radiation dose, and incorporate the normal tissue repair factor into the equivalent uniform dose model. Make the model more perfect, can provide more accurate prediction for clinical.
【学位授予单位】：清华大学
【学位级别】：硕士
【学位授予年份】：2010
【分类号】：R311
本文编号：2426634
[Abstract]:Radiotherapy is showing the following two main research directions: 1. Optimization and improvement of fractionation dose and treatment scheme for radiotherapy. 2. To improve the distribution of radiation dose in vivo. These two aspects must be based on the accurate pre-evaluation of the therapeutic effect, that is, the accurate judgment of the radiobiological behavior of the tumor and the organ endangering it. Dose volume histogram is the main method to judge the therapeutic results in clinic, and its technical defects are also obvious. First of all, it is impossible to compare the radiobiological response for the plan with the same statistical value and different dose distribution. Second, the plan can only be described in terms of doses at several reference points on the map. Finally, the plan for the same total dose cannot be compared with different partitioning doses. On the basis of Niemierko study, the proliferation effect of tumor cells during radiotherapy was considered. On the basis of the original equivalent uniform dose mathematical model, the variable of potential doubling time was added to improve the model. The treatment plan with different dose distribution, different dose gradient distribution and different interval time of irradiation has a comparison approach and reference, which overcomes the weakness of dose volume histogram. Under the change of different parameters, the weight of each parameter in this model and the difference and relation between each model are determined by comparing the change trend and degree of the equivalent uniform dose with the 1995 edition, the 1999 edition and the potential doubling time. The characteristics of each model and its suitable application fields and conditions. The statistical comparison of the lung equivalent uniform dose and the traditional volume dose parameters of 40 patients receiving radiation therapy was carried out, and the reference value of evaluating the radiation damage to normal tissues was further studied. The suggested a value for the study of lung radiation injury is also proposed. The results show that the equivalent uniform dose can overcome the difficulty of evaluating the biological effects of lung tissue in different planning images and different grades of lung tissue, and can predict the radiation injury well, which has certain clinical application value. In this paper, we compared the 99 version of large segmented dose treatment plan with that of three-dimensional conformal radiation plan and the equivalent uniform dose with potential doubling time, and analyzed that the model of equivalent uniform dose was used to study the large segmented irradiation and the different times of irradiation. Evaluation of radiobiological effects of different intervals of irradiation on tumors. It has been shown that the effect of cell doubling effect on the radiotherapy results of tumor tissue can be reflected sensitively by the equivalent uniform dose, especially with the potential doubling time, which has certain clinical application value. At the end of the paper, some suggestions are put forward to further improve the mathematical model of equivalent uniform dose. We consider converting the potential doubling time into a function of total radiation dose, and incorporate the normal tissue repair factor into the equivalent uniform dose model. Make the model more perfect, can provide more accurate prediction for clinical.
【学位授予单位】：清华大学
【学位级别】：硕士
【学位授予年份】：2010
【分类号】：R311
【共引文献】
相关硕士学位论文 前1条
1 董令仪;超分割放射治疗宫颈癌与其细胞凋亡相关基因表达关系的研究[D];广西医科大学;2008年
，本文编号：2426634
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