Biomaterial Database

[Influence of cavities on dose distribution in electron depth therapy]. 1975

D Fehrentz, and H Krone, and P Schröder-Babo

The influence of body cavities on the dose distributions of electrons between 15 and 42 MeV has been studied by means of ionometric and densitometric measurements in polystyrol and cork phantoms. The results show that superelevated doses appear behind the cavities near the surface of the head and the neck caused by scattered electrons of about 10% of the maximum dose in the homogene muscle tissue, particulary by small electron energies. The dose points are spatial very limited with diameters of 1 to 2 cm. With greater depths, i.e. for electron energies of 10, 25 and 42 MeV from 2, 4 and 6 cm respectively, no more superelevated dose caused by the electron scattering appears. All the other body cavities, particulary in the lungs and in the gastrointestinal tract, have for that reason an influence on the dose distribution essentially by the electron radius increased with the cavity length. The electron scattering and the organ motions provide for an great dose equalization.

UI	MeSH Term	Description	Entries
D008168	Lung	Either of the pair of organs occupying the cavity of the thorax that effect the aeration of the blood.	Lungs
D008433	Mathematics	The deductive study of shape, quantity, and dependence. (From McGraw-Hill Dictionary of Scientific and Technical Terms, 6th ed)	Mathematic
D009132	Muscles	Contractile tissue that produces movement in animals.	Muscle Tissue,Muscle,Muscle Tissues,Tissue, Muscle,Tissues, Muscle
D009333	Neck	The part of a human or animal body connecting the HEAD to the rest of the body.	Necks
D011879	Radiotherapy Dosage	The total amount of radiation absorbed by tissues as a result of radiotherapy.	Dosage, Radiotherapy,Dosages, Radiotherapy,Radiotherapy Dosages
D011882	Radiotherapy, High-Energy	Radiotherapy using high-energy (megavolt or higher) ionizing radiation. Types of radiation include gamma rays, produced by a radioisotope within a teletherapy unit; x-rays, electrons, protons, alpha particles (helium ions) and heavy charged ions, produced by particle acceleration; and neutrons and pi-mesons (pions), produced as secondary particles following bombardment of a target with a primary particle.	Megavolt Radiotherapy,High-Energy Radiotherapy,Radiotherapy, Megavolt,High Energy Radiotherapy,Radiotherapy, High Energy
D004058	Diffusion	The tendency of a gas or solute to pass from a point of higher pressure or concentration to a point of lower pressure or concentration and to distribute itself throughout the available space. Diffusion, especially FACILITATED DIFFUSION, is a major mechanism of BIOLOGICAL TRANSPORT.	Diffusions
D004064	Digestive System	A group of organs stretching from the MOUTH to the ANUS, serving to breakdown foods, assimilate nutrients, and eliminate waste. In humans, the digestive system includes the GASTROINTESTINAL TRACT and the accessory glands (LIVER; BILIARY TRACT; PANCREAS).	Ailmentary System,Alimentary System
D006257	Head	The upper part of the human body, or the front or upper part of the body of an animal, typically separated from the rest of the body by a neck, and containing the brain, mouth, and sense organs.	Heads
D006801	Humans	Members of the species Homo sapiens.	Homo sapiens,Man (Taxonomy),Human,Man, Modern,Modern Man