The estimation of radiation effect to cancer patients treated with beam-therapy by means of analysis of chromosomal aberrations in blood lymphocytes

The goal of the study was to investigate local and whole-bogy doses to lung cancer patients received fractionated beam-therapy. The biological dosimetry based on the analysis of chromosomal aberrations in blood lymphocytes was used. The group comprised 25 lung cancer patients that exhibited II to IV developmental clinical stage has been examined. All the patients received the accumulated tumor dose ranged 47.5 to 70 Gy by means of g-ray 60Co radiation machines «Luch» or «Rokus». The blood was sampled as following: before treatment, after the first day, after the complete course of beam-therapy and time-by-time during the post treatment period up to about two years. The chromosomal aberrations were analyzed in the first mitosis cells using conventional method. It was found that individual response of patients to beam-therapy varied greatly even after comparable irradiation conditions. The examined groups have been statistically subdivided into three subgroup of high, intermediate and low radiation sensitivity using observed frequency of chromosomal radiation markers. The tumor dose and side whole-body dose were estimated for all the subgroups by means of biodosimetry model based on incomplete-repair theory. The specialty of cytogenetic dose assessment of lung cancer patients found in this study confirms the necessity for individual practice toward planning and executing the therapeutic regimen of cancer patients. The increasing of efficiency and avoiding of side effect could be expected in this way.