The Induction of Chromosome Aberrations during the Course of Radiation Therapy for Morbus Hodgkin

Abstract

In a patient with Morbus Hodgkin, structural aberrations of the chromosome type in peripheral lymphocytes were analyzed during radiation therapy (accumulated target dose 44.6 Gy: 22 fractions of 1.8 Gy each and 2 fractions of 2.5 Gy each at the end of the therapy). The blood was sampled about 5 min after a fraction and/or 24, 48, or 72 h thereafter. The frequency of dicentric chromosomes:acentric fragments:centric ring chromosomes is 37:14:1 throughout the therapy. Independent of the time of blood sampling after a fraction, the distributions of dicentrics and acentrics are overdisperse and represent negative binomial distributions. The yields from these aberrations, as determined during the course of radiotherapy, are best fitted to a linear-quadratic function with a negative quadratic term. The two dose-effect curves (blood sampling about 5 min and 24 to 72 h after a fraction) of dicentrics and acentrics do not differ significantly. Up to an accumulated target dose of about 20 Gy the percentages of cells with chromosome aberrations increase to about 48 to 65% and, at this level, remain constant until the end of therapy.

Cytogenetic assessment of heterogeneous radiation doses in cancer patients treated with fractionated radiotherapy

“…The influence of treatment parameters on the yield of dicentrics and rings and on the distribution of these aberrations was also studied. As previously described, the yield of dicentrics and rings increased with the tumour dose for each patient but with substantial interindividual variability [24][25][26]. In agreement with other studies, a strong correlation between the size of irradiation field and the yield of chromosome aberrations was found [12,26,27].…”

Cytogenetic damage in lymphocytes for the purpose of dose reconstruction: a review of three recent radiation accidents

“…A higher than expected frequency of dicentrics and micronuclei was also observed in lymphocytes of one of the control patients. It has been observed by different authors that the frequencies of aberrations and micronuclei in lymphocytes of patients undergoing radiotherapy are strongly variable between individuals (Obe et al, 1981;Diener et al, 1988). The reasons for this variability are not well understood.…”

Comparison of the Micronucleus and Chromosome Aberration Techniques for the Documentationof Cytogenetic Damage in Radiochemotherapy-Treated Patients with Rectal Cancer

“…Cytogenetic techniques, including the widely used analysis of chromosome aberrations [2,8,15,26,27,31,34,37,46] and the nowadays frequently used micronucleus test [3, 7, 9, 16, 23, 25, 28, 31, 34-36, 39, 42], are not only reliable indicators of damage to the cell genome in vivo and in vitro, but are also applicable for different and combined radiation qualities [45]. Our data agree with other authors mentioned above who demonstrated that RTX causes structural chromosome damage.…”

“…Concerning the CAT, a dose-dependent increase in the yield of CA frequency has been shown in RTX of patients at different sites [2,8,26,27]. It is a sensitive method for dose estimation but requires a very detailed analysis, which is very laborious and complex.…”