BIOLOGY BASED OPTIMIZATION OF INTENSITY MODULATED 3DCRT

描述：(改编自调查人员的摘要)这一目标 该项目旨在证明将生物指数纳入 强度调制的优化可以产生显著的 3D适形治疗计划与相应计划相比的改进 纯粹基于剂量和简单剂量-体积进行优化的计划 标准。强度调制提供了大大增强的控制 超剂量分布。这种控制可以最大限度地被利用来 使用复杂的优化技术实现预期结果。 然而，重要的是，优化的目标是 以临床相关的方式指定，以便结果 临床效果最佳。基于剂量、基于剂量-体积和基于生物学 强度调制优化技术将应用于组 前列腺、脑和肺的3D适形治疗计划。这些计划 将在它们之间以及与最好的非强度- 由计划者设计的经过调整的治疗计划。结果将是 用来评估不同行业的相对优势和劣势 并探讨它们之间存在差异的原因。 强度调制优化方法--初级版本 其中已落实的前期工作，将进一步细化。 所选模型(串联、并行或现象学)的影响 计算熟练程度上的生物学指标及其参数 并将检验优化过程的效率。对于每个 一类放射治疗问题，模型的参数将是 调整以产生与以下判断一致的结果 医生和规划者以及已公布的数据。方法将 以准确地解释辐射的非局部性质 剂量沉积在最佳强度分布设计中的应用。这个 准确计算离散度对最优性的重要性 将对强度调制计划进行调查。对于每个站点和 阶段，强度调制处理的最佳束流数目 将会被确定。包含非共面梁的值将为 探索过了。使用阿尔法-贝塔模型，潜在的放射生物学 涉及强度的各种分级方案的后果- 将对调制处理进行比较。数学方面的问题 强度调制优化方法，包括多个最小值和 将研究加速优化过程的方法。 预计拟议调查的结果将是 允许制定强度调节治疗计划，在该计划中 对于相同或更低的剂量，肿瘤的剂量可能会显著增加 正常组织损伤的可能性，潜在地改善了局部控制 因此，生存也是如此。

DESCRIPTION: (adapted from the investigator's abstract) The goal of this project is to demonstrate that incorporating biological indices into the optimization of intensity-modulation can result in a significant improvement in 3D conformal treatment plans compared to corresponding plans which are optimized based purely on dose and simple dose-volume criteria. Intensity modulation provides a greatly increased control over dose distributions. Such control can be maximally exploited to achieve the desired results using sophisticated optimization techniques. However, it is important that the objectives of optimization be specified in a clinically relevant manner in order that the results be clinically optimum. Dose-based, dose-volume based and biology-based intensity modulation optimization techniques will be applied to groups of prostate, brain and lung 3D conformal treatment plans. These plans will be compared among themselves as well as with the best non-intensity- modulated treatment plans designed by a planner. The results will be used to evaluate the relative strengths and weaknesses of various techniques and to explore the reasons for the differences between them. The intensity-modulation optimization methodology, a rudimentary version of which has been implemented in the preliminary work, will be refined. The impact of the models (serial, parallel or phenomenological) chosen to compute biological indices and their parameters on the proficiency and efficiency of the optimization process will be examined. For each class of radiotherapy problems, the parameters of the models will be adjusted to produce results that are consistent with the judgment of physicians and planners as well as with published data. Methods will be developed to accurately account for the non-local nature of radiation dose deposition in the design of optimum intensity distributions. The importance of accurate accounting of scatter on the optimality of intensity-modulated plans will be investigated. For each site and stage, the optimum number of beams for intensity-modulated treatments will be determined. The value of including non-coplanar beams will be explored. Using alpha-beta models, the potential radiobiological consequences of the various fractionation schemes involving intensity- modulated treatments will be compared. Mathematical aspects of intensity-modulation optimization methods, including multiple minima and methods to accelerate the optimization process, will be investigated. It is expected that the outcome of the proposed investigations will permit the development of intensity-modulated treatment plans in which dose to the tumor can be escalated significantly for the same or lower probability of normal tissue damage, potentially improving local control and hence, survival.