Biomaterial Database

The use of the D versus dD plot to estimate the alpha/beta ratio from iso-effect radiation damage data. 1988

R W de Boer

Radiotherapy Department, The Netherlands Cancer Institute, (Antoni van Leeuwenhoekhuis), Amsterdam.

In studies of radiation damage, the parameter alpha/beta of the linear-quadratic (LQ) model is usually estimated from iso-effect data by plotting the iso-effect doses in a so-called Fe-plot, which is a plot of the inverse total dose versus dose per fraction. This method, however, is statistically not well founded. A better, but relatively complex technique to estimate the alpha/beta ratio was described by Tucker. The present contribution shows that results, virtually identical to the ones of Tucker can be obtained in a very simple way if the iso-effect doses are plotted as total dose Dn versus the product of dose per fraction and total dose, Dndn. A reliable estimator of the alpha/beta ratio consists then of the negative inverse slope of the linear-regression line in this plot. The presentation of iso-effect data in such a D-dD plot highlights deviations from the LQ model more clearly than does the Fe-plot. It is therefore suggested to use the D-dD plot as a quick and easy graphical scheme to obtain an estimate of alpha/beta.

UI	MeSH Term	Description	Entries
D011829	Radiation Dosage	The amount of radiation energy that is deposited in a unit mass of material, such as tissues of plants or animal. In RADIOTHERAPY, radiation dosage is expressed in gray units (Gy). In RADIOLOGIC HEALTH, the dosage is expressed by the product of absorbed dose (Gy) and quality factor (a function of linear energy transfer), and is called radiation dose equivalent in sievert units (Sv).	Sievert Units,Dosage, Radiation,Gray Units,Gy Radiation,Sv Radiation Dose Equivalent,Dosages, Radiation,Radiation Dosages,Units, Gray,Units, Sievert
D011833	Radiation Injuries, Experimental	Experimentally produced harmful effects of ionizing or non-ionizing RADIATION in CHORDATA animals.	Experimental Radiation Injuries,Injuries, Experimental Radiation,Experimental Radiation Injury,Radiation Injury, Experimental
D004307	Dose-Response Relationship, Radiation	The relationship between the dose of administered radiation and the response of the organism or tissue to the radiation.	Dose Response Relationship, Radiation,Dose-Response Relationships, Radiation,Radiation Dose-Response Relationship,Radiation Dose-Response Relationships,Relationship, Radiation Dose-Response,Relationships, Radiation Dose-Response
D006801	Humans	Members of the species Homo sapiens.	Homo sapiens,Man (Taxonomy),Human,Man, Modern,Modern Man
D000818	Animals	Unicellular or multicellular, heterotrophic organisms, that have sensation and the power of voluntary movement. Under the older five kingdom paradigm, Animalia was one of the kingdoms. Under the modern three domain model, Animalia represents one of the many groups in the domain EUKARYOTA.	Animal,Metazoa,Animalia