Comparison of dose distribution of ionizing radiation in a water phantom with frequency of cytogenetic damage in a human bronchial cells

摘要

In this study we compare dose distribution of photon and electron radiation in a water phantom with a frequency of occurrence of apoptotic and micronucleated cells from human bronchial BEAS-2B and lung cancer AS49 cell lines. Formation of micronuclei and apoptotic like bodies were evaluated by the cytokinesis-block micronucleus test. Measurements were performed on a five depths (3-20 cm) in a water phantom. Cells were irradiated in a beam axis or beyond field. As the irradiation source, a linear accelerator was used. Results indicate discrepancy between physical dose distribution observed on different depths in a water environment and biological effects (frequency of apoptosis and micronuclei formation). This discrepancy is specially significant for cells placed outside the field during exposure to radiation. Evaluation of these effects could be useful for modeling low-dose radiation risk and for radiotherapy protocols.