[Tumor cell kinetics in uterine cervical carcinoma following irradiation]

15 cases of squamous cell carcinoma of uterine cervix which received radiotherapy were investigated in order to elucidate tumor cell kinetics following irradiation. The DNA content of Pararosanillin-Feulgen stained tumor cells were measured by fluorescence cytophotometry which provided great precision in the field of microspectrophotometry. Besides the cell preparation, tumor cells were precisely identified under blue light excitation (405nm). It is of great value to obtain a reliable DNA histogram of tumor cells with this method. In both groups of radioresistant cases (n = 3) and radiosensitive cases (n = 12), the same trend in cell kinetics was noted until 1400 rad, such as G2-block, endoreduplication, and a decrease in the 2c cell (G0 + G1) population. Most of the residual cells at 3000 rad of radioresistant cases showed little irradiation-induced morphological change. These cells were proved to be 2C cells in this study. This indicates that these radioresistant cells were non-cycling cells (G0). The mean value for the 2C cell population before irradiation was 65% in radioresistant cases and 46% in radiosensitive cases, respectively. The former contained a larger proportion of 2C cells than the latter. Clinically, the 2C cell population before irradiation may be used as a useful parameter to forecast radiosensitivity.