Biomaterial Database

Stopping-power ratio for a photon spectrum as a weighted sum of the values for monoenergetic photon beams. 1985

P Andreo, and A E Nahum

Stopping-power ratios for water to air, Sw,air, have been calculated for 60Co and thin-target bremsstrahlung beams. The Monte Carlo method was used to generate depth-dependent Sw,air values and depth-absorbed-dose distributions in water for monoenergetic photon beams covering the energy range 0.1-50 MeV. An averaging procedure has been developed to derive the stopping-power ratios for a photon spectrum from the monoenergetic data. Values of the Spencer-Attix ratio for delta = 10 keV, SSAw,air (delta = 10 keV), and the Bragg-Gray ratio, SBGw,air, evaluated using the new I values and two different sets of values for the density effect correction, are given at the reference depths recommended in the dosimetry protocols.

UI	MeSH Term	Description	Entries
D008953	Models, Anatomic	Three-dimensional representation to show anatomic structures. Models may be used in place of intact animals or organisms for teaching, practice, and study.	Anatomic Models,Models, Surgical,Moulages,Models, Anatomical,Anatomic Model,Anatomical Model,Anatomical Models,Model, Anatomic,Model, Anatomical,Model, Surgical,Moulage,Surgical Model,Surgical Models
D009010	Monte Carlo Method	In statistics, a technique for numerically approximating the solution of a mathematical problem by studying the distribution of some random variable, often generated by a computer. The name alludes to the randomness characteristic of the games of chance played at the gambling casinos in Monte Carlo. (From Random House Unabridged Dictionary, 2d ed, 1993)	Method, Monte Carlo
D011878	Radiotherapy	The use of IONIZING RADIATION to treat malignant NEOPLASMS and some benign conditions.	Radiotherapy, Targeted,Targeted Radiotherapy,Radiation Therapy,Radiation Therapy, Targeted,Radiation Treatment,Targeted Radiation Therapy,Radiation Therapies,Radiation Therapies, Targeted,Radiation Treatments,Radiotherapies,Radiotherapies, Targeted,Targeted Radiation Therapies,Targeted Radiotherapies,Therapies, Radiation,Therapies, Targeted Radiation,Therapy, Radiation,Therapy, Targeted Radiation,Treatment, Radiation
D011879	Radiotherapy Dosage	The total amount of radiation absorbed by tissues as a result of radiotherapy.	Dosage, Radiotherapy,Dosages, Radiotherapy,Radiotherapy Dosages
D006801	Humans	Members of the species Homo sapiens.	Homo sapiens,Man (Taxonomy),Human,Man, Modern,Modern Man