Challenges in radiobiological modeling: can we decide between LQ and LQ-L models based on reviewed clinical NSCLC treatment outcome data?

• DOI: 10.1186/s13014-016-0643-5
• Publication Date: 2016-05-06T07:39:06Z
• Authors: Alina Santiago; Steffen Barczyk; Urszula Jelen; Rita Engenhart-Ca...; Andrea Wittig
• Keywords: Relative biological effectiveness; Isocenter

To study the dose-response of stage I non-small-cell lung cancer (NSCLC) in terms long-term local tumor control (LC) after conventional and hypofractionated photon radiotherapy, modeled with linear-quadratic (LQ) linear-quadratic-linear (LQ-L) approaches to estimate clinical α/β ratio within LQ frame. We identified studies curative radiotherapy as single treatment through MedLine search reporting 3-year LC primary outcome interest. Logistic models coupled biologically effective dose (BED) at isocenter PTV edge according both LQ-L = 10 Gy were fitted. Additionally, was estimated from direct fits. Thirty one included 2319 patients. The fit yielded a significant value 11.0 ± 5.2 for threshold (Dt) BED10 isocenter. fits did not differ substantially. Concerning estimation α/β, obtained complete fractionation range 3.9 [68 % CI: 2.2–9.0] (p > 0.05). Both can model conventionally irradiation are robust methods predicting effects. observed dose-effect NSCLC is weaker high doses due data dispersion. For values 100–150 ≥3 fractions, differences isoeffects predicted by be neglected.