# Hypofractionation (fewer, larger radiotherapy doses)

Source: https://onco.cc/terms/hypofractionation/  
OnCo record `hypofractionation` (Term). Data CC BY-NC 4.0, attribute "Data from OnCo (onco.cc)"; commercial use needs a licence.

## TL;DR

Giving radiotherapy in fewer, bigger daily doses (fractions) so a course takes one to three weeks instead of five to seven. Randomised trials showed equal control and side effects in breast (START, FAST-Forward) and prostate (CHHiP, PACE-B) cancer, and a single dose suffices for bone pain; adoption lags where health systems are paid per fraction.

## Summary

Normal tissue tolerates radiation better when it is split into daily fractions, historically 1.8-2 Gy over 5-7 weeks. Randomised trials showed moderate hypofractionation (2.7-3 Gy, 15-20 fractions) is equivalent in breast (START, whole-breast 40 Gy/15) and prostate (CHHiP, PROFIT), and ultra-hypofractionation (5 fractions: FAST-Forward for breast 26 Gy/5, PACE-B for prostate) also holds up. Single 8 Gy fractions suffice for bone pain. SBRT takes the principle to its extreme. Short-course (5 × 5 Gy) rectal radiotherapy is part of total neoadjuvant therapy. Adoption lags in some health systems that are paid per fraction.

## Fields

- Kind: Term
- Last checked: 2026-09-09
- Also known as: hypofractionated; hypofractionated radiotherapy; ultra-hypofractionated; ultrahypofractionation; moderate hypofractionation; fractionation; fractions; fractionated; single-fraction; five-fraction; conventional fractionation; conventionally fractionated; accelerated fractionation; dose per fraction; short-course radiotherapy; short-course; long-course

## Sources

- Wikipedia: https://en.wikipedia.org/wiki/Hypofractionation
- Wikipedia: https://en.wikipedia.org/wiki/Hypofractionation

## Connected records

- terms: [Bone metastases and skeletal-related events](https://onco.cc/terms/bone-metastases/), [Brachytherapy (internal radiotherapy)](https://onco.cc/terms/brachytherapy-term/), [Gray unit (Gy)](https://onco.cc/terms/gray-unit/), [How many radiotherapy visits: the prostate fractionation trials](https://onco.cc/terms/prostate-radiotherapy-fractionation/), [IMRT / IGRT / VMAT (modern external beam radiotherapy)](https://onco.cc/terms/imrt-term/), [Leaving radiotherapy out](https://onco.cc/terms/radiotherapy-omission-early-breast-cancer/), [Lumpectomy (breast-conserving surgery)](https://onco.cc/terms/lumpectomy/), [Non-inferiority margin and equivalence trials](https://onco.cc/terms/non-inferiority-margin/), [Non-inferiority trial](https://onco.cc/terms/non-inferiority/), [Partial-breast irradiation](https://onco.cc/terms/partial-breast-irradiation/), [Radiotherapy after mastectomy](https://onco.cc/terms/post-mastectomy-radiotherapy/), [Stereotactic body radiotherapy (SBRT / SABR)](https://onco.cc/terms/sbrt-term/), [Total neoadjuvant therapy (TNT, rectal cancer)](https://onco.cc/terms/total-neoadjuvant-therapy/), [Tumour bed boost](https://onco.cc/terms/tumour-bed-boost/)
- cancers: [Breast cancer (all types)](https://onco.cc/cancers/breast-cancer/), [Colorectal cancer](https://onco.cc/cancers/colorectal/), [HR-positive / HER2-negative breast cancer](https://onco.cc/cancers/breast-hr-positive/), [Prostate cancer](https://onco.cc/cancers/prostate/)
- fronts: [Radiation Therapy](https://onco.cc/fronts/radiation/)
- trials: [CHHiP](https://onco.cc/trials/chhip/), [FAST (5-fraction whole-breast radiotherapy)](https://onco.cc/trials/fast-trial/), [FAST-Forward](https://onco.cc/trials/fast-forward/), [PROFIT (Prostate Fractionated Irradiation Trial)](https://onco.cc/trials/profit-trial/), [RAPID (accelerated partial-breast irradiation)](https://onco.cc/trials/rapid/), [RTOG 0415](https://onco.cc/trials/rtog-0415/), [START-A (UK Standardisation of Breast Radiotherapy, trial A)](https://onco.cc/trials/start-a/), [START-B (UK Standardisation of Breast Radiotherapy)](https://onco.cc/trials/start-b/)
- institutions: [Mount Vernon Cancer Centre](https://onco.cc/institutions/mount-vernon-cancer-centre/)
- roadmaps: [Global access and affordability roadmap: essential medicines and generics → biosimilars and frugal trials → reliance, pooling and homegrown innovation](https://onco.cc/roadmaps/global-access-roadmap/), [Radiotherapy roadmap: X-rays → shaped beams → fewer fractions, particles and FLASH](https://onco.cc/roadmaps/radiation-roadmap/)
- companies: [Accuray](https://onco.cc/companies/accuray/)
- technologies: [Hypofractionated radiotherapy](https://onco.cc/technologies/hypofractionated-radiotherapy/), [The linear-quadratic model and fractionation](https://onco.cc/technologies/linear-quadratic-model/)

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