fractionation
Division of total radiation dose into multiple smaller doses delivered over time to maximize therapeutic effect.
Full Definition
Fractionation in radiation oncology refers to the practice of dividing the total prescribed radiation dose into multiple smaller doses (fractions) delivered over several days or weeks. This approach exploits differences between normal and cancer tissue in repair mechanisms, reoxygenation, redistribution, and repopulation. Standard fractionation typically delivers 1.8-2.0 Gy per fraction daily. Hypofractionation uses larger doses per fraction with fewer total fractions, while hyperfractionation uses smaller, more frequent doses. The fractionation schedule significantly impacts both tumor control and normal tissue toxicity.
Usage
Usage note: May be modified as hypofractionation, hyperfractionation, or accelerated fractionation.
In Context
- "The patient will receive conventional fractionation with 30 fractions over six weeks." — Radiation therapy plan
- "Hypofractionated radiotherapy was chosen to reduce treatment duration." — Clinical notes