[125I-iododeoxyuridine in the reaction of experimental tumors to irradiation]

A study was made of the kinetics of 125I-iodo-desoxyuridine clearance after x-ray irradiation of experimental tumors sarcoma-180 and melanoma B-16 at doses of 2, 10, 20 and 40 Gy. Change in the level of radioactive label within the time interval of 0.25-48 h was approximated by exponential function (r2-0.92-0.98) or straight lines on a graph in the semilogarithmic scale. Their inclination angles differed significantly for the above doses. Correlations were obtained between the ratio of the rates of change of radioactivity in the irradiated and control tumors within the interval of 0.25-48 h after the administration of 125I-iododesoxyuridine and parameters which characterized growth of the above tumors in various irradiation regimens. The analytical expressions obtained are applicable to quantitative assessment of a tumor response to irradiation.