Biomaterial Database

Contribution of electron contamination to the skin dose in teletherapy with Co-60 gamma-rays. 1980

R N Kulkarni

The contribution of electron contamination to the dose received by the skin and the underlying tissues during teletherapy with 60Co gamma-rays has been determined by an indirect method. First, the distribution of dose under the skin due to an uncontaminated beam of 60Co gamma-rays was determined using the Monte Carlo method without any major assumption. This distribution was then subtracted from the measured distribution of total dose available in the literature, to get the required dose distribution due to electron contamination. The distribution as determined in this work has been compared with that determined by some other workers, who relied on the dose distribution due to an uncontaminated beam calculated under some assumptions. It was found that the dose due to electron contamination was overestimated by them in the middle depths. This was as expected, because with their assumptions in the calculation of the dose distribution due to an uncontaminated beam, this dose is underestimated in the middle depths.

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
D011867	Radioisotope Teletherapy	A type of high-energy radiotherapy using a beam of gamma-radiation produced by a radioisotope source encapsulated within a teletherapy unit.	Teleradioisotope Therapy,Teletherapy, Radioisotope,Therapy, Teleradioisotope
D011879	Radiotherapy Dosage	The total amount of radiation absorbed by tissues as a result of radiotherapy.	Dosage, Radiotherapy,Dosages, Radiotherapy,Radiotherapy Dosages
D003037	Cobalt Radioisotopes	Unstable isotopes of cobalt that decay or disintegrate emitting radiation. Co atoms with atomic weights of 54-64, except 59, are radioactive cobalt isotopes.	Radioisotopes, Cobalt
D004583	Electrons	Stable elementary particles having the smallest known negative charge, present in all elements; also called negatrons. Positively charged electrons are called positrons. The numbers, energies and arrangement of electrons around atomic nuclei determine the chemical identities of elements. Beams of electrons are called CATHODE RAYS.	Fast Electrons,Negatrons,Positrons,Electron,Electron, Fast,Electrons, Fast,Fast Electron,Negatron,Positron
D012867	Skin	The outer covering of the body that protects it from the environment. It is composed of the DERMIS and the EPIDERMIS.