title: Fractionation in radiotherapy (review).
abstract: The methods by which radiation treatment has been administered since the original discoveries concerning the properties of ionising radiation are reviewed on a historical basis. The criteria, together with their limitations, that have influenced the empirical approach to fractionation in radiotherapy are identified and critically assessed. The necessity for classifying fractionation into component parts, so as to avoid confusion, such as time, dose and fractions factors is stressed, as is the correct evaluation of the complex biological consequences of the physical events. The different mechanisms, and their varying inter-relationships, responsible for acute and late normal tissue radiation damage are considered and shown not to relate solely to the time factor. Reports from the literature are used to illustrate these points.
mesh_terms: D000818:Animals; D002493:Central Nervous System Diseases / Q000209:etiology; D005591:Chemical Fractionation; D004890:Erythema / Q000209:etiology; D005767:Gastrointestinal Diseases / Q000209:etiology; D006801:Humans; D007674:Kidney Diseases / Q000209:etiology; D051379:Mice; D009369:Neoplasms / Q000532:radiotherapy; D011014:Pneumonia / Q000209:etiology; D011832:Radiation Injuries / Q000209:etiology; D011878:Radiotherapy / Q000009:adverse effects; D011879:Radiotherapy Dosage; D051381:Rats