modification of 10 cgy neutron or gamma-rays induced chromosomal damages by hyperthermia: an in vitro study

background: to evaluate the effects of hyperthermia (ht) on the frequency of chromosomal aberrations induced by a low dose of neutron or γ-rays in human peripheral blood lymphocytes. materials and methods: blood samples were exposed to ht (41.5°c for 30 and 60min, 43°c for 15 and 30min), 10 cgy neutron or γ-rays, ht + neutron/γ, and neutron/γ + ht. after standard cell culture, harvesting, fixation and staining, the chromosomal damages were scored in metaphase plates. results: ht alone at 41.5°c did not induce chromatid or chromosome aberrations, however, the frequency of damages was significantly higher at 43°c (p<0.05). furthermore, the chromosomal damages was significantly different when cells were irradiated with neutron or γ-rays alone (p<0.01). ht 1 hr post neutron/γ irradiation significantly induced higher chromosome damages in comparison to ht 1 hr before irradiation (p<0.05). the chromosomal damages were remarkably higher when cells were irradiated with neutron then heated at 43°c for 30 min. conclusion: since increasing frequency of chromosome damages increases probability of cell death, application of ht after neutron irradiation (instead of x– or γ- rays) might be considered as a procedure for cells killing in radiotherapy. iran. j. radiat. res., 2009 7 (2): 69-77