Response of Chinese Hamster V79 Multicellular Spheroids Exposed to High-Energy Carbon Ions
| Autor: | Wolfgang Mueller-Klieser, M. Scholz, S. Walenta, A. Staab, D. Zukowski |
|---|---|
| Rok vydání: | 2004 |
| Předmět: |
Cell Survival
Biophysics Analytical chemistry chemistry.chemical_element Apoptosis Bragg peak Radiation Dosage Oxygen Chinese hamster Cell Line Ion Cricetulus Cricetinae Relative biological effectiveness Animals Radiology Nuclear Medicine and imaging Carbon Radioisotopes Irradiation Radiation biology X-Rays Cell Cycle Spheroid Dose-Response Relationship Radiation biology.organism_classification chemistry Atomic physics Carbon Cell Division Relative Biological Effectiveness |
| Zdroj: | Radiation Research. 161:219-227 |
| ISSN: | 1938-5404 0033-7587 |
| DOI: | 10.1667/rr3113 |
| Popis: | Chinese hamster V79-379A spheroids 200 +/- 30 microm (+/- SD) in diameter were irradiated in agitated medium in different oxygen atmospheres with (1) 227 MeV/nucleon (12)C(+6) ions (plateau region) to model tissue in the entrance channel during therapy, (2) carbon ions in the extended Bragg peak modeling tissue in the target volume, or (3) X rays as a reference modality. Cell survival curves were similar for modes (1) and (3), indicating the absence of a contact effect and the presence of a pronounced oxygen effect with oxygen enhancement ratios (OERs) of 2.8 and 2.9, respectively. In contrast, the oxygen effect was substantially smaller in mode (2) with an OER of 1.4. Under normal or restricted oxygen supply conditions (external pO(2) = 145 or 0 mmHg), the relative biological effectiveness (RBE) was 2.1 or 4.3, respectively, for Bragg-peak irradiation. This modality induced apoptosis and a dose-dependent accumulation of cells in G(2)/M phase even at pO(2) = 0 mmHg. The volume ratios of treated to untreated spheroids exhibited cyclic variations after heavy-particle treatment that were not directly attributable to cell cycle synchronization. In summary, the results suggest that carbon ions in the extended Bragg peak are more effective than conventional X rays, particularly under hypoxic conditions. |
| Databáze: | OpenAIRE |
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