[Prediction of radiosensitivity by micronucleus assay]

Area of Science:

• Radiation biology
• Cellular and molecular oncology
• Biophysical modeling

Context:

• Assessing cellular response to radiation is crucial for effective cancer therapy.
• Traditional methods for determining radiosensitivity can be time-consuming.
• The linear-quadratic model is a standard for analyzing radiation dose-response relationships.

Purpose:

• To investigate the correlation between cell survival curves and micronucleus (MN) frequency dose-response curves after irradiation.
• To evaluate the MN frequency assay using the cytokinesis-block (CB) method as a tool for rapid radiosensitivity assessment.
• To analyze dose-response curves using the linear-quadratic model (SF = exp(-αD - βD²) and MN frequency = aD + bD² + c).

Summary:

• A strong correlation (γ = 0.97) was observed between the α/β and a/b ratios in paired experiments, validating the MN assay.
• Treatment with an α-type radiosensitizer (BUdR) increased the 'a' value but not the 'b' value in the MN frequency dose-response curve.
• Linear correlations between cell surviving fractions and MN frequencies were found in renal cell carcinomas, and a wide range of a/b ratios was observed in esophageal cancer cell lines.

Impact:

• The MN frequency assay using the CB method is a viable tool for rapid radiosensitivity assessment in cancer research.
• This assay can potentially expedite the evaluation of patient-specific responses to radiotherapy.
• Findings support the use of cytogenetic assays for predicting radiobiological effectiveness in clinical settings.