fractionation

1. To separate components of a mixture. 2. The administration of a course of therapeutic radiation of a neoplasm in a planned series of fractions of the total dose, most often once a day for several weeks, in order to minimize radiation damage of contiguous normal tissues.

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frac·tion·a·tion .frak-shə-'nā-shən n the action or process of fractionating <\fractionation of blood plasma by the precipitation of blood proteins> also the state of being fractionated

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frac·tion·a·tion (frak″shən-aґshən) 1. in radiotherapy, division of the total dose of radiation into small doses administered at intervals, which usually causes less biological damage than the same total dose given at one time; see also hyperfractionation. Called also dose fractionation. 2. division of the total dosage of a drug into smaller doses (fractional doses) administered at frequent intervals. Called also dose f. 3. in chemistry, separation of a substance into components, as by distillation or crystallization. 4. in histology, isolation of components of living cells by differential centrifugation.