Basic Clinical Radiobiology 2017

Prototypes of modified fractionation

• Hyperfractionation (HF) • Accelerated fractionation (AF)

• (Hybrid schedules) • Hypofractionation

ESTRO 2017

Fractionation sensitivity

Late effects

“Typical” dose per fraction • 1.8-2 Gy for standard fractionation • 1.1-1.3 Gy for hyper- fractionation

Acute effects + tumor response

ESTRO 2017

Withers et al, 1983