EN
We report a case of a testicular seminoma patient
with relapse who was irradiated after acute cerebral
infarction induced by cisplatin-based chemotherapy.
Lymphocytic genome instability was studied using an
alkaline comet assay, analysis of structural chromosome
aberrations, and cytokinesis-block micronucleus assay
in blood samples collected before and after PET CT
scanning that preceded radiotherapy, as well as before the
administration of the first and after the administration of
the last fraction of 3D conformal radiation. A challengetest
with hydrogen peroxide (H2O2) was performed on
isolated peripheral blood lymphocytes in order to establish
to what extent earlier therapies had modified the response
of the patient’s DNA to external stimuli with a genotoxic
chemical. Levels of primary DNA damage in lymphocytes
increased after diagnostic exposure, lowered prior to
administration of a conformal 3D radiotherapy, and were
the highest at the end of radiotherapy. Ex vivo exposure to
H2O2 caused additional lymphocyte DNA damage, which
gradually increased 15 and 30 minutes after treatment.
Diagnostic and therapeutic exposure to radiation caused
measurable cytogenetic damage that was subjected
to extensive repair. All of the obtained results point to
increased genomic instability in the patient which should
be taken into account in his future medical surveillance.