Karyoanomalic frequency during radiation therapy.

Aim: To identify the relationship between the radiosensitivity of oral cancers and to evaluate the dose-dependent relationship of nuclear abnormalities by serial cytology during fractionated radiotherapy in head and neck cancer patients.
Materials and Methods: 30 patients with histologically proven cases of squamous cell carcinoma were included in the study. Serial scrape smear were taken from the tumor before and during radiotherapy (0 to 24 Gy), and stained with Giemsa and May Grunwald's stain and frequency of micronucleated, binucleated and multinucleated cells were evaluated with the help of light microscope. The counts were expressed per 1000 uninucleated cells.
Results: Each parameter showed a statistical increase with increase dose. Before treatment, the mean values of micronucleated cells, binucleated cells and multinucleated cells were 3.5, 10.1 and 4.2. At 4 Gy these were 7.7, 12.0 and 6.2 which further increased with radiation dose; and the mean values were 8.8, 16.2 and 14.9 at 14 Gy and 12.8, 18.5 and 15.1 at 24 Gy. After analysis of p-value, all such abnormal cells showed significant difference (p < 0.0001) with respect to normal subjects.
Conclusion: Our study results that micronucleus assay is a very useful tool in the assessment of biological damage that can help to identify tumor radiosensitivity.