Biomaterial Database

A beam profile generation algorithm for wedged half-beam blocked asymmetric fields. 1994

A E Millin, and C W Smith

Radiotherapy Physics Service, Velindre Hospital, Whitchurch, Cardiff, UK.

A method is presented to predict beam profiles and outputs for wedged asymmetric fields defined by independent collimator jaws allowing fast generation of beam profiles whilst requiring very little additional data to that already used by most treatment planning systems in generating symmetric field isodoses. Symmetric field data are modified by the use of wedged primary off-centre ratios (POCRS) which are obtained from in air measurements of the largest possible wedged field. Beam hardening occurring within the flattening filter and wedge is taken into account by the use of attenuation coefficients measured under each wedge and used to generate the wedged POCR at depth. A full investigation into the comparison between measured and calculated profiles was performed which demonstrates favourable agreement across the whole of the asymmetric field including the penumbra.

UI	MeSH Term	Description	Entries
D008433	Mathematics	The deductive study of shape, quantity, and dependence. (From McGraw-Hill Dictionary of Scientific and Technical Terms, 6th ed)	Mathematic
D008962	Models, Theoretical	Theoretical representations that simulate the behavior or activity of systems, processes, or phenomena. They include the use of mathematical equations, computers, and other electronic equipment.	Experimental Model,Experimental Models,Mathematical Model,Model, Experimental,Models (Theoretical),Models, Experimental,Models, Theoretic,Theoretical Study,Mathematical Models,Model (Theoretical),Model, Mathematical,Model, Theoretical,Models, Mathematical,Studies, Theoretical,Study, Theoretical,Theoretical Model,Theoretical Models,Theoretical Studies
D010315	Particle Accelerators	Devices which accelerate electrically charged atomic or subatomic particles, such as electrons, protons or ions, to high velocities so they have high kinetic energy.	Betatrons,Linear Accelerators,Accelerator, Linear,Accelerator, Particle,Accelerators, Linear,Accelerators, Particle,Betatron,Linear Accelerator,Particle Accelerator
D011881	Radiotherapy, Computer-Assisted	Computer systems or programs used in accurate computations for providing radiation dosage treatment to patients.	Computer-Assisted Radiotherapy,Radiation Therapy, Computer-Assisted,Computer-Assisted Radiation Therapy,Computer Assisted Radiation Therapy,Computer Assisted Radiotherapy,Computer-Assisted Radiation Therapies,Computer-Assisted Radiotherapies,Radiation Therapies, Computer-Assisted,Radiation Therapy, Computer Assisted,Radiotherapies, Computer-Assisted,Radiotherapy, Computer Assisted,Therapies, Computer-Assisted Radiation,Therapy, Computer-Assisted Radiation
D006801	Humans	Members of the species Homo sapiens.	Homo sapiens,Man (Taxonomy),Human,Man, Modern,Modern Man
D000465	Algorithms	A procedure consisting of a sequence of algebraic formulas and/or logical steps to calculate or determine a given task.	Algorithm