Biological estimation of dose in hemi-body irradiation of cancer patients by cytogenetic analysis.

The objective of this study was to estimate equivalent whole body dose and dose to the irradiated region in hemi-body irradiation of cancer patients using chromosome aberrations and micronuclei techniques. The frequency of unstable chromosome aberrations and micronuclei was studied in peripheral blood lymphocytes of cancer patients before and after hemi-body irradiation. The mean estimated equivalent whole body dose was 3.74 +/- 0.16 Gy and 4.07 +/- 0.15 Gy from dicentrics and micronuclei frequency in lymphocytes after hemi-body irradiation. The mean dose to the irradiated region from unstable chromosome aberrations was estimated to be 6.85 +/- 0.2 Gy and 6.79 +/- 0.26 Gy using Dolphin's contaminated Poisson dispersion analysis and the Qdr method, respectively. The mean dose to the irradiated region from micronuclei frequency was 7.04 +/- 0.25 Gy by Dolphin's method. There was a slight underestimation of mean dose to the irradiated part in vivo. The percentage of irradiated blood and fraction of the cells exposed could be estimated using the contaminated Poisson method.