Estimation of dose in cancer patients treated with fractionated radiotherapy using translocation, dicentrics and micronuclei frequency in peripheral blood lymphocytes

The frequency of translocation, dicentrics (DC) and micronuclei (MN) was st udied in blood samples exposed in vitro to Co-60 gamma radiation and cervic al cancer patients undergoing fractionated radiotherapy. The samples expose d under in vitro condition showed that the frequency of translocation and d icentric followed Poisson distribution ('u' varied between -0.04 and +1.41 for translocation and between -0.09 and +1.81 for DC) and that obtained wit h MN follow over dispersion ('u' varied between +2.04 and +9.28). However, the cervical cancer patients undergoing radiotherapy showed over dispersion for all these three aberrations (DC, MN and translocation). The frequencie s of aberrations obtained in cancer patients were found to be lower than th ose obtained for in vitro exposure for doses more than 2 Gy equivalent whol e body dose (EWBD). The dose-response curves were constructed using the fre quencies of DC, MN and translocation as a function of EWBD. Doses as measur ed from the dose response curves were compared with the estimated dose in o rder to check whether the measured and estimated doses agree. The percent v ariation between the doses measured from aberration frequencies and that of the estimated dose was lower with translocation (10.8 +/- 7.41%) compared to those obtained with DC (38.08 +/- 31.85%) and MN (47.19 +/- 31.80%). (C) 1999 Elsevier Science B.V. All rights reserved.