Düchting W, Ulmer W, Ginsberg T, Saile C
Department of Electrical Engineering and Computer Science, University of Siegen.
Strahlenther Onkol. 1995 Aug;171(8):460-7.
Based on control theory, the attempt is made in this paper to construct a computer model which describes the time course of fast proliferating normal tissue after irradiation treatment. Subsequently, different clinical irradiation schemes are compared in regard to their radiogenic acute effects.
A cybernetic model of a cell renewal system consisting of stem-, transit- and functional cells has been developed and transferred into a computer model. The radiation effects are considered by characteristic cell parameters as well as by the linear-quadratic model.
Three kinds of tissue (thick epidermis of man, thin epidermis of the mouse and jejunum of the mouse) have been irradiated in the model in accordance with different clinical irradiation schemes (standard-, super-, hyperfractionation and a single high dose per week). The simulation studies demonstrate that the acute reaction of normal tissue to hyperfractionation (3 times 1.5 Gy per day) is particularly severe. Furthermore, the radiation damage of the jejunum and of the thin epidermis of the mouse depends on the specific irradiation scheme and is only partially compensated.
A comparison of the simulation results with clinical experience (and practice) demonstrates that the clinical reality can in quality be successfully represented by the model. This opens the door for connecting the side effects of irradiation to normal tissue with the corresponding tumor effectiveness (see our previous papers about irradiation of tumor spheroids.
基于控制理论，本文尝试构建一个计算机模型，用以描述放射治疗后快速增殖的正常组织的时间进程。随后，比较不同临床放射治疗方案的放射性急性效应。
已开发出一个由干细胞、过渡细胞和功能细胞组成的细胞更新系统的控制论模型，并将其转化为计算机模型。通过特征细胞参数以及线性二次模型来考虑辐射效应。
按照不同临床放射治疗方案（标准分割、超分割、高分割以及每周单次高剂量照射），在模型中对三种组织（人类厚表皮、小鼠薄表皮和小鼠空肠）进行了照射。模拟研究表明，正常组织对高分割照射（每天3次，每次1.5 Gy）的急性反应尤为严重。此外，小鼠空肠和薄表皮的辐射损伤取决于具体的照射方案，且仅得到部分补偿。
模拟结果与临床经验（及实践）的比较表明，该模型能够在质量上成功地反映临床实际情况。这为将放射治疗的副作用与正常组织以及相应的肿瘤疗效联系起来打开了大门（见我们之前关于肿瘤球体照射的论文）。
