ABSTRACT
In this study we tried to define incidence and types of chromosomal aberrations (CAs) caused by radiotherapy (RT) in circulating lymphocytes from patients with lung cancer. For this purpose, we used cumulative dose–effect relationship, and correlate these data with statistical parameters. CAs were evaluated in terms of chromosome break, dicentric, ring and chromosome gap. Abnormal metaphase number (AMN) was also calculated. Chromosome studies were carried out in peripheral blood lymphocytes of 20 cancer patients receiving RT. Patients were treated with 10 Gy of gamma (g) radiation during five wk(s). In all patients, a significant increase in AMN and frequency of CAs (e.g. chromosome break, dicentric, ring and chromosome gap) observed during the RT depend on cumulative radiation dose when compared to before RT, and this increase was statistically significant (p<0.05). The highest CAs frequency was observed at the end of fifth wk. Among the CAs, chromosome breaks have a high incidence. But no CAs and abnormal metaphase was observed in lymphocytes before RT. The present study showed that RT possess a significant effect in increasing of CAs and chromosome break, dicentric, ring and chromosome gap are very sensitive and useful biomarkers in the study of this effect. In other words, these CAs may be used as possible fingerprints of RT.