AbstractID: 9720 Title: Analyzing the fractionation and dose-rate effect in radiotherapy with kinetic cell
killing model
The linear-quadratic (LQ) model and its extension, the incomplete repair (IR) model is
the major tool for analyzing and understanding the fractionation and dose-rate effect in
radiotherapy. As the limitation of the more mechanistic models under low dose and low
dose rate condition it is not adequate to be used for the procedures such as radiosurgery
which gives a high dose in one fraction and high-dose-rate (HDR) branchytherapy. In this
work the kinetic radiobiological model is used to analyze the fractionation and dose-rate
effect on radiotherapy outcome. The lethal and potential lethal (LPL) model is chosen
because it contains the essence of the lesion-interaction mechanism and has fewer
parameters than its recently developed version, the two-lesion kinetic (TLK) model,
which includes more detailed rejoining process of double-strand breaks (DSB). The cell
killing vs. time with different fraction doses and separations are shown for different doserate. This provide a simulation for the real treatment, which has complicated time factors,
such as the interrupts of the dose deliver in radiosurgery procedure due to isocenter
changes. The equivalent fractionation for radiosurgery is plotted as guidance for
optimization.