Biomaterial Database

Measurements and Monte Carlo simulations of the fluence and dose characteristics of microplanar photon beams. 1996

F Z Company, and B J Allen

Department of Physics, University of Western Sydney Nepean, Kingswood, NSW Australia.

The lateral absorbed dose, depth dose and photon fluence in a water phantom of a single microplanar beam is investigated using the Monte Carlo method. To validate the calculated axial and scattered photon fluence, an experiment is carried out using a NaI(TI) detector and 20 mCi Cd-109 source at energies of 22 keV and 88 keV. A 150 microns collimator is used to produce the microplanar beam, and the integrated scattered photon fluence is measured over 2.5 microns increments. The axial (depth) photon fluence is in good agreement with the calculated results. The scattered (lateral) photon fluence results agree to within two standard deviations.

UI	MeSH Term	Description	Entries
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
D011879	Radiotherapy Dosage	The total amount of radiation absorbed by tissues as a result of radiotherapy.	Dosage, Radiotherapy,Dosages, Radiotherapy,Radiotherapy Dosages
D002106	Cadmium Radioisotopes	Unstable isotopes of cadmium that decay or disintegrate emitting radiation. Cd atoms with atomic weights 103-105, 107, 109, 115, and 117-119 are radioactive cadmium isotopes.	Radioisotopes, Cadmium
D015233	Models, Statistical	Statistical formulations or analyses which, when applied to data and found to fit the data, are then used to verify the assumptions and parameters used in the analysis. Examples of statistical models are the linear model, binomial model, polynomial model, two-parameter model, etc.	Probabilistic Models,Statistical Models,Two-Parameter Models,Model, Statistical,Models, Binomial,Models, Polynomial,Statistical Model,Binomial Model,Binomial Models,Model, Binomial,Model, Polynomial,Model, Probabilistic,Model, Two-Parameter,Models, Probabilistic,Models, Two-Parameter,Polynomial Model,Polynomial Models,Probabilistic Model,Two Parameter Models,Two-Parameter Model
D019047	Phantoms, Imaging	Devices or objects in various imaging techniques used to visualize or enhance visualization by simulating conditions encountered in the procedure. Phantoms are used very often in procedures employing or measuring x-irradiation or radioactive material to evaluate performance. Phantoms often have properties similar to human tissue. Water demonstrates absorbing properties similar to normal tissue, hence water-filled phantoms are used to map radiation levels. Phantoms are used also as teaching aids to simulate real conditions with x-ray or ultrasonic machines. (From Iturralde, Dictionary and Handbook of Nuclear Medicine and Clinical Imaging, 1990)	Phantoms, Radiographic,Phantoms, Radiologic,Radiographic Phantoms,Radiologic Phantoms,Phantom, Radiographic,Phantom, Radiologic,Radiographic Phantom,Radiologic Phantom,Imaging Phantom,Imaging Phantoms,Phantom, Imaging