{"entity":{"id":"hypofractionation","kind":"term","name":"Hypofractionation (fewer, larger radiotherapy doses)","aka":["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"],"tldr":"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.","asOf":"2026-09-09","wikipedia":"https://en.wikipedia.org/wiki/Hypofractionation","links":[{"label":"Wikipedia","url":"https://en.wikipedia.org/wiki/Hypofractionation"}],"tags":[],"related":["gray-unit","sbrt-term","imrt-term","total-neoadjuvant-therapy","partial-breast-irradiation","post-mastectomy-radiotherapy"],"cancers":["breast-hr-positive","prostate","colorectal","breast-cancer"],"sections":["radiation"],"technologies":[],"targets":[],"drugs":[],"companies":[],"institutions":[],"pathways":[],"terms":[],"trials":["start-a","fast-trial"],"people":[],"bottlenecks":[],"keyPapers":[],"journals":[],"dependsOn":[],"notes":[],"category":"Treatment jargon"},"route":"/terms/hypofractionation/","neighbours":{"term":[{"id":"bone-metastases","kind":"term","name":"Bone metastases and skeletal-related events","route":"/terms/bone-metastases/"},{"id":"brachytherapy-term","kind":"term","name":"Brachytherapy (internal radiotherapy)","route":"/terms/brachytherapy-term/"},{"id":"gray-unit","kind":"term","name":"Gray unit (Gy)","route":"/terms/gray-unit/"},{"id":"prostate-radiotherapy-fractionation","kind":"term","name":"How many radiotherapy visits: the prostate fractionation trials","route":"/terms/prostate-radiotherapy-fractionation/"},{"id":"imrt-term","kind":"term","name":"IMRT / IGRT / VMAT (modern external beam radiotherapy)","route":"/terms/imrt-term/"},{"id":"radiotherapy-omission-early-breast-cancer","kind":"term","name":"Leaving radiotherapy out","route":"/terms/radiotherapy-omission-early-breast-cancer/"},{"id":"lumpectomy","kind":"term","name":"Lumpectomy (breast-conserving surgery)","route":"/terms/lumpectomy/"},{"id":"non-inferiority-margin","kind":"term","name":"Non-inferiority margin and equivalence trials","route":"/terms/non-inferiority-margin/"},{"id":"non-inferiority","kind":"term","name":"Non-inferiority trial","route":"/terms/non-inferiority/"},{"id":"partial-breast-irradiation","kind":"term","name":"Partial-breast irradiation","route":"/terms/partial-breast-irradiation/"},{"id":"post-mastectomy-radiotherapy","kind":"term","name":"Radiotherapy after mastectomy","route":"/terms/post-mastectomy-radiotherapy/"},{"id":"sbrt-term","kind":"term","name":"Stereotactic body radiotherapy (SBRT / SABR)","route":"/terms/sbrt-term/"},{"id":"total-neoadjuvant-therapy","kind":"term","name":"Total neoadjuvant therapy (TNT, rectal cancer)","route":"/terms/total-neoadjuvant-therapy/"},{"id":"tumour-bed-boost","kind":"term","name":"Tumour bed boost","route":"/terms/tumour-bed-boost/"}],"cancer":[{"id":"breast-cancer","kind":"cancer","name":"Breast cancer (all types)","route":"/cancers/breast-cancer/"},{"id":"colorectal","kind":"cancer","name":"Colorectal cancer","route":"/cancers/colorectal/"},{"id":"breast-hr-positive","kind":"cancer","name":"HR-positive / HER2-negative breast cancer","route":"/cancers/breast-hr-positive/"},{"id":"prostate","kind":"cancer","name":"Prostate cancer","route":"/cancers/prostate/"}],"section":[{"id":"radiation","kind":"section","name":"Radiation Therapy","route":"/fronts/radiation/"}],"trial":[{"id":"chhip","kind":"trial","name":"CHHiP","route":"/trials/chhip/"},{"id":"fast-trial","kind":"trial","name":"FAST (5-fraction whole-breast radiotherapy)","route":"/trials/fast-trial/"},{"id":"fast-forward","kind":"trial","name":"FAST-Forward","route":"/trials/fast-forward/"},{"id":"profit-trial","kind":"trial","name":"PROFIT (Prostate Fractionated Irradiation Trial)","route":"/trials/profit-trial/"},{"id":"rapid","kind":"trial","name":"RAPID (accelerated partial-breast irradiation)","route":"/trials/rapid/"},{"id":"rtog-0415","kind":"trial","name":"RTOG 0415","route":"/trials/rtog-0415/"},{"id":"start-a","kind":"trial","name":"START-A (UK Standardisation of Breast Radiotherapy, trial A)","route":"/trials/start-a/"},{"id":"start-b","kind":"trial","name":"START-B (UK Standardisation of Breast Radiotherapy)","route":"/trials/start-b/"}],"institution":[{"id":"mount-vernon-cancer-centre","kind":"institution","name":"Mount Vernon Cancer Centre","route":"/institutions/mount-vernon-cancer-centre/"}],"roadmap":[{"id":"global-access-roadmap","kind":"roadmap","name":"Global access and affordability roadmap: essential medicines and generics → biosimilars and frugal trials → reliance, pooling and homegrown innovation","route":"/roadmaps/global-access-roadmap/"},{"id":"radiation-roadmap","kind":"roadmap","name":"Radiotherapy roadmap: X-rays → shaped beams → fewer fractions, particles and FLASH","route":"/roadmaps/radiation-roadmap/"}],"company":[{"id":"accuray","kind":"company","name":"Accuray","route":"/companies/accuray/"}],"technology":[{"id":"hypofractionated-radiotherapy","kind":"technology","name":"Hypofractionated radiotherapy","route":"/technologies/hypofractionated-radiotherapy/"},{"id":"linear-quadratic-model","kind":"technology","name":"The linear-quadratic model and fractionation","route":"/technologies/linear-quadratic-model/"}]}}