| Autor: |
Antipina, Natalia, Golanov, Andrey, Nikolaeva, Anna, Pavlova, Galina, Ovechkina, Anna |
| Předmět: |
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| Zdroj: |
Journal of Radiosurgery & SBRT; 2022 Supplement, Vol. 8, p171-172, 2p |
| Abstrakt: |
Optimal schemes of irradiation for recuurensed glioblatomas not determined yet. An important task is to assess the radiosensitivity of human glioblastoma cells when exposed to various total and single doses and understanding whether radiosensitivity changes with repeated irradiation of cells. Cell cultures that were selected for the study were obtained from 6 patients during removing glioblastoma (GB), three of whom underwent radiation therapy before the second surgery, and three more patients had not previously been irradiated. Irradiation was carried out on by TrueBeam STx linac (Varian, USA). A bremsstrahlung photon beams energy of 6 MeV were chosen for the experiment in a wide range of doses and three different fractionation regimens: 1, 3 and 5 fractions. To assess the response of cells to irradiation, the changes in their proliferative activity were assessed by the MTT test. The dose ranges for irradiation for 3 and 5 fractions had to be equivalent to a single exposure, so they were calculated using the biologically effective dose (BED) and LQ models. The shape of the dose-effect curves obtained by us in this experimental study is not uniformly decreasing, as according to the accepted LQ model. The dynamics for cells from a previously irradiated tumor and tumors undergoing irradiation for the first time were markedly different. The number of fractions of irradiation influences to the shape of the dose-response curve. For cells previously exposed to irradiation, the drop in proliferative activity at low doses was not so significant, which indicates that the subpopulation of radiosensitive cells was smaller. The sensitivity of GB culture›s cells during repeated irradiation is lower at all dose intervals, which indicated the resistance of such cells to irradiation. Quantitative estimates of dose-response curves could be used to predict the response of glioblastomas to irradiation in clinical practice, to select the most effective and safe irradiation regimens, to assess the risks and prospects for the use of repeated irradiation in case of relapses. It is necessary to build a mathematical model that most accurately describes the dynamics of changes in the metabolic activity of cells depending on the dose of ionizing radiation. The research was supported financially by RFBR (Project No. 18-29-01061). [ABSTRACT FROM AUTHOR] |
| Databáze: |
Complementary Index |
| Externí odkaz: |
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