Beck-Bornholdt H P
Institute of Biophysics and Radiobiology, University of Hamburg.
Strahlenther Onkol. 1988 Mar;164(3):155-64.
A review is given of data published on the response of experimental tumours to fractionated irradiation including ten or more fractions. In addition experiments performed with the R1H rhabdomyosarcoma of the rat including regimens of six to 126 fractions (dose range 0.43 to 12.5 Gy per fraction) with an overall treatment time of six weeks are reported. Tumour response was assessed by: in vitro colony assay, tumour control probability, tumour growth delay, and flow cytometric determination of DNA-index. While a clear reduction of normal tissue damage is observed with increasing number of fractions, the response of the R1H-rhabdomyosarcoma is essentially independent of the number of fractions. This result encourages clinical research on the use of hyperfractionation for curative radiotherapy. The results also indicate that proliferation is decelerated during treatment. During irradiation the DNA-index of the highly hyperploid R1H-tumour cells decreases. This reduction is proportional to the total dose applied. Cells that are separated from the tumour and from metastases have defined DNA-indices. Thus, this special tumour system allows to determine the time point of onset of metastatic spread from flow cytometric DNA-index measurements.
本文综述了已发表的关于实验性肿瘤对分割照射（包括十个或更多分割）反应的数据。此外，还报告了对大鼠R1H横纹肌肉瘤进行的实验，包括六至126个分割的方案（每分割剂量范围为0.43至12.5 Gy），总治疗时间为六周。通过以下方式评估肿瘤反应：体外集落测定、肿瘤控制概率、肿瘤生长延迟以及DNA指数的流式细胞术测定。虽然随着分割次数增加，正常组织损伤明显减少，但R1H横纹肌肉瘤的反应基本上与分割次数无关。这一结果鼓励了关于超分割用于根治性放疗的临床研究。结果还表明，治疗期间增殖减缓。照射期间，高度超二倍体的R1H肿瘤细胞的DNA指数降低。这种降低与所施加的总剂量成比例。从肿瘤和转移灶分离出的细胞具有确定的DNA指数。因此，这个特殊的肿瘤系统能够通过流式细胞术DNA指数测量来确定转移扩散开始的时间点。
