LET-based approximation of the microdosimetric kinetic model for proton radiotherapy

Parisi, A.*; Furutani, K. M.*; Sato, Tatsuhiko   ; Beltran, C. J.*

In this study, we have developed an approximate MKM (microdosimetric kinetic model) based on LET (dose-averaged linear energy transfer) to address the challenges of biological relative effectiveness (RBE) models for proton therapy. This is an attempt to apply the mechanism-based approach used in carbon ion therapy to proton beams. This LET-based MKM establishes a correlation between dose-averaged LET and microbiological indices and successfully models survival rates for multiple cell lines. This has resulted in a mathematical description of RBE based on physical quantities that can be readily used in proton therapy planning systems.