Inherent radiosensitivity testing of tumor biopsies obtained from patients with carcinoma of the cervix or endometrium.

The inherent radiosensitivity of tumor biopsies obtained from a series of patients with carcinoma of the uterine cervix or endometrium has been characterized. Early passage cell lines were irradiated and assayed for cell survival using a clonogenic assay system. Survival curves were generated using the alpha/beta model and the surviving fraction at 2 Gy (SF2) was estimated. A wide range of SF2 values was observed among histologically similar tumors. The mean (+/- SD) SF2 value was 0.29 +/- 0.12 (range = 0.11-0.59) for the cervical biopsies and 0.30 +/- 0.13 (range = 0.11-0.67) for the endometrial biopsies. No correlation between inherent radiosensitivity and tumor DNA index or histopathology was observed. Patient accrual continues with the expectation that these results may help to determine whether SF2 values are of clinical value in predicting the response of individual patients to treatment with radiotherapy.