Effect of variable dose rate on biologically effective dose
| Autor: | Greg S. Spradlin, Vadim Y. Kuperman |
|---|---|
| Rok vydání: | 2013 |
| Předmět: |
Time Factors
Radiological and Ultrasound Technology α β ratio business.industry Chemistry Normal tissue Dose per fraction Models Biological Effective dose (radiation) Linear Models Relative biological effectiveness Radiology Nuclear Medicine and imaging Dose rate Nuclear medicine business Relative Biological Effectiveness Probability |
| Zdroj: | International Journal of Radiation Biology. 89:889-897 |
| ISSN: | 1362-3095 0955-3002 |
| DOI: | 10.3109/09553002.2013.811308 |
| Popis: | Purpose: To investigate the effect of variable dose rate on biologically effective dose (BED). Materials and methods: By using the linear-quadratic (LQ) model with bi-exponential repair, we analytically determine the timedependent dose rate R ~ which minimizes the effective protraction factor (G eff ) and BED under the condition of fixed fraction time and dose per fraction. Because normal tissue complication probability (NTCP) monotonically decreases with decreasing BED, the dose rate R also minimizes NTCP. Results: The dependences of G eff , BED and NTCP on fraction time were determined for different radiobiological parameters and two different dose rates: constant dose rate R 0 and varying dose rate R . Conclusion: The results of this study indicate that under certain conditions the reduction in BED for late-responding tissues due to increased fraction time can be significantly greater than the reduction in BED for tumors. Our analysis also indicates that dose rate optimization can be radiobiologically beneficial because of the resulting decrease in NTCP. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|
| Nepřihlášeným uživatelům se plný text nezobrazuje | K zobrazení výsledku je třeba se přihlásit. |