Radiobiological responses for two cell lines following continuous low dose-rate (CLDR) and pulsed dose rate (PDR) brachytherapy
Autor: | Per Henrik Hanisch, Erik O. Pettersen, Dag Rune Olsen, Torbjørn Furre |
---|---|
Rok vydání: | 2007 |
Předmět: |
G2 Phase
Cell Survival medicine.medical_treatment Brachytherapy Pulsed dose rate Cell Line Tumor medicine Humans Radiology Nuclear Medicine and imaging Low dose rate Irradiation Beta (finance) business.industry Radiochemistry Dose fractionation Dose-Response Relationship Radiation Radiotherapy Dosage DNA Neoplasm Hematology General Medicine Flow Cytometry Pdr brachytherapy Oncology Cell culture Dose Fractionation Radiation Nuclear medicine business |
Zdroj: | Acta Oncologica. 46:602-611 |
ISSN: | 1651-226X 0284-186X |
Popis: | The iso-effective irradiation of continuous low-dose-rate (CLDR) irradiation was compared with that of various schedules of pulsed dose rate (PDR) irradiation for cells of two established human lines, T-47D and NHIK 3025. Complete single-dose response curves were obtained for determination of parameters alpha and beta by fitting of the linear quadratic formula. Sublethal damage repair constants micro and T(1/2) were determined by split-dose recovery experiments. On basis of the acquired parameters of each cell type the relative effectiveness of the two regimens of irradiation (CLDR and PDR) was calculated by use of Fowler's radiobiological model for iso-effect irradiation for repeated fractions of dose delivered at medium dose rates. For both cell types the predicted and observed relative effectiveness was compared at low and high iso-effect levels. The results indicate that the effect of PDR irradiation predicted by Fowlers model is equal to that of CLDR irradiation for both small and large doses with T-47D cells. With NHIK 3025 cells PDR irradiation induces a larger effect than predicted by the model for small doses, while it induces the predicted effect for high doses. The underlying cause of this difference is unclear, but cell-cycle parameters, like G2-accumulation is tested and found to be the same for the two cell lines. |
Databáze: | OpenAIRE |
Externí odkaz: |