Download CytoBayesJ: Software tools for Bayesian analysis of

COMPARISON OF CHROMOSOME ABERRATIONS OUTCOME IN CANCER
PATIENTS WITH DIFFERENT TUMOR LOCALIZATIONS UNDERGONE 60CO
RADIOTHERAPY
Maznyk Nataliya,a Sypko Tetyana,a Pshenichna Nataliya,a Krugova Irina,a Zabobonina
Larisa,a Shustov Igor,a StarenkiyViktor a
a
Institute for Medical Radiology of the National Academy of Medical Science of Ukraine,
Pushkinskaya St. 82, Kharkiv, 61024;
[email protected]
The estimation of the cytogenetic effects in peripheral blood lymphocytes of cancer patients
is an important task in the development of radiobiological basis of radiotherapy. In order to
improve biological dosimetry in radiotherapy and to estimate the risk to health resulting from
medical irradiation, it is necessary to evaluate the mechanisms of fractionated partial-body
radiation action at chromosome level.
Chromosome and chromatid aberrations were analyzed in lymphocytes of 24 radiotherapy
patients divided on three groups depending on tumor localization: with lung cancer, with
uterine body cancer and with head and neck cancer. Blood sampling was performed before
treatment, at the middle and at the end of external 60Co radiotherapy course, reaching the dose
of 40-45 Gy. Lymphocytes were cultivated by conventional technique, FPG-staining control
of cell division was applied.
Slightly but significantly elevated over spontaneous level of chromosome aberrations was
found in all groups of patients, before treatment. The differences in chromosome and
chromatid type aberrations accumulation behavior during radiotherapy course depending on
tumor localization were observed. The almost monotonic increase of radiation-induced
aberrations from start to the end of treatment in patients with uterine cancer and lung cancer
and less pronounced changes in these parameters in patients with head and neck cancers were
demonstrated. Thus after radiotherapy the mean yield of unstable chromosome type
aberrations was increased above pre-treatment levels 27-30-fold in groups with uterine cancer
and with lung cancer in compare with 7-8-fold in group with head and neck cancers. The
distribution of the dicentrics among cells was found to be over-dispersed according to
Poisson statistic both at the middle and at the end of radiotherapy course in all groups. The
chromatid type aberrations were more pronounced in patients with lung cancer.
The peculiarities of cytogenetic damage outcome in patients with various tumor localizations
and subsequently different positions and sizes of irradiated fraction of the body along with
the value of these studies for cancer patients medical monitoring after radiological treatment
will be discussed.