MODELING OF TIME-DOSE RESPONSE OF HUMAN TUMORS AND NORMAL TISSUES

放射治疗的目的是控制肿瘤。从克隆原的角度看 在最短的时间内提供必要的剂量是有意义的 时间越长越好。肿瘤治疗中的限制因素是正常的 组织反应：正常的组织反应不能超过“耐受性” 水平。特别是高技术的发展和应用 在计算机和以计算机为基础的辅助成像方面 在肿瘤定位和治疗计划方面取得了重大进展，甚至在 交付技术及其质量保证，即空间 问题的方方面面。关于剂量和剂量的决策 随时间的分布(通过分馏或延长)仍然是 然而，本质上是经验性的。本项目继续 时间-剂量理论描述的发展与探索 肿瘤和正常组织的反应。它的基本概念有 发表于1988年[1]。从那时起，进一步的事态发展 重点研究了线性-二次模型的推广。延伸区 涉及到对不完全修复的影响和 包括对肿瘤增殖和干细胞的影响的描述 细胞/过渡细胞再繁殖。一项关于其影响的研究 高剂量阿利特与低剂量率近距离治疗的对比正在进行中。这 工作集中在相关的不确定因素的影响 参数，特别是a/b和时间因素。这项工作包括 开发交互式计算机程序和图形工具以 帮助临床指导寻找与高剂量率兼容的 持续的肿瘤控制以及没有更严重的毒性。

The purpose of radiation therapy is tumor control. In view of clonogen proliferation it makes sense to deliver the necessary dose in as short a time as possible. The limiting factor in tumor treatment is normal tissue reaction: normal tissue reactions must not exceed "tolerance" level. The development and application of high technology particularly in computers and computer-based and assisted imaging has stimulated great progress in tumor localization and treatment planning, and even in the technology of delivery and its quality assurance, i.e., the spatial aspects of the issue. Decision-making as to the amount of dose and its distribution over time (by fractionation or protraction) is still essentially empirical, however. The present project continues the development and exploration of a theoretical description of time-dose response of tumors as well as normal tissues. Its basic concepts have been published in 1988[1]. Since then, further developments have concentrated on extension of the Linear-Quadratic model. The extension concerns a unified description of the influence of incomplete repair and comprises a description of the influence of tumor proliferation and stem cell/transition cell repopulation. A study regarding the implications of high dose arate vs. low dose rate brachytherapy is ongoing. This work concentrates on the implications of uncertainties in the relevant parameters, particularly a/b and the time factor. The work includes the development of an interactive computer program and graphical tools to help clinical guidance in the search for high dose rates compatible with constant tumor control as well as no more severe toxicity.