Biomaterial Database

Buildup region of high-energy x-ray beams in radiosurgery. 1993

K E Sixel, and E B Podgorsak

Department of Physics, McGill University, Montréal, Québec, Canada.

The depths of dose maxima of radiosurgical x-ray beams increase with the field diameter in the range from 10-30 mm. Furthermore, the degree of the increase is proportional to the photon beam energy. This behavior is in contrast to that of large radiotherapeutic fields, where the depths of dose maxima decrease with increasing field size. The surface doses, depths of dose maxima, and collimator scatter factors for radiosurgical beams with energies between 6 and 18 MV are presented. It is shown that the change in dmax for radiosurgical beams is a result of photon scatter in the phantom rather than in the collimator. Monte Carlo simulations of the radiosurgical beams are used to separate the total dose into two components: the primary dose and the scattered dose. Calculations indicate that buildup region characteristics are governed by the primary dose deposition in the medium. The scattered dose has a minimal effect on the total dose deposited in media by radiosurgical beams.

UI	MeSH Term	Description	Entries
D008961	Models, Structural	A representation, generally small in scale, to show the structure, construction, or appearance of something. (From Random House Unabridged Dictionary, 2d ed)	Model, Structural,Structural Model,Structural 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
D003198	Computer Simulation	Computer-based representation of physical systems and phenomena such as chemical processes.	Computational Modeling,Computational Modelling,Computer Models,In silico Modeling,In silico Models,In silico Simulation,Models, Computer,Computerized Models,Computer Model,Computer Simulations,Computerized Model,In silico Model,Model, Computer,Model, Computerized,Model, In silico,Modeling, Computational,Modeling, In silico,Modelling, Computational,Simulation, Computer,Simulation, In silico,Simulations, Computer
D006801	Humans	Members of the species Homo sapiens.	Homo sapiens,Man (Taxonomy),Human,Man, Modern,Modern Man
D016634	Radiosurgery	A radiological stereotactic technique developed for cutting or destroying tissue by high doses of radiation in place of surgical incisions. It was originally developed for neurosurgery on structures in the brain and its use gradually spread to radiation surgery on extracranial structures as well. The usual rigid needles or probes of stereotactic surgery are replaced with beams of ionizing radiation directed toward a target so as to achieve local tissue destruction.	Gamma Knife Radiosurgery,Linear Accelerator Radiosurgery,Stereotactic Body Radiotherapy,Stereotactic Radiosurgery,CyberKnife Radiosurgery,LINAC Radiosurgery,Radiosurgery, Gamma Knife,Radiosurgery, Linear Accelerator,Radiosurgery, Stereotactic,Stereotactic Radiation,Stereotactic Radiation Therapy,CyberKnife Radiosurgeries,Gamma Knife Radiosurgeries,LINAC Radiosurgeries,Linear Accelerator Radiosurgeries,Radiation Therapy, Stereotactic,Radiation, Stereotactic,Radiosurgery, CyberKnife,Radiosurgery, LINAC,Radiotherapy, Stereotactic Body,Stereotactic Body Radiotherapies,Stereotactic Radiation Therapies,Stereotactic Radiations,Stereotactic Radiosurgeries,Therapy, Stereotactic Radiation