In radiotherapy the normal tissue reaction is often a limiting factor for radiation treatment. Still there is no
screening method, which predicts normal tissue reaction on radiotherapy, especially in comparison to tumor tissue, and
therefore allows tailoring of the radiation dose to each patient. Here, we present a case of severe radiation-related side effects.
We applied classical cytogenetic techniques (Giemsa-banding and staining of centromeric regions), the comet assay
as well as multicolor fluorescence in situ hybridization on peripheral blood lymphocytes of this patient in order to determine
the radio-sensitivity on the DNA level and to correlate these findings with the clinical outcome. Our investigations
revealed abnormalities on chromosome 9, deficiencies in the DNA-repair capacity after radiation exposure and a high
number of radiation induced chromosomal aberrations. A detected high amount of residual damage two or three hours after
radiation exposure and repair as well as the high number of chromosomal aberrations (ChAs) suggests a correlation between
repair capacity and radiation induced ChAs. We concluded that the detected abnormalities might serve as a genetic
basis for the radio-sensitive phenotype of this patient. Taken together this report strengthens the idea that intensive DNA
genomic analysis of individual patients can serve as the basis for more favourable treatment of cancer patients.
Keywords: Radiation therapy, DNA damage and repair, Double strand breaks, Comet assay, Radiation induced chromosomal
aberrations, M-FISH, radio-sensitivity, situ hybridization, Giemsa-Trypsin-Giemsa, centromere
Rights & PermissionsPrintExport