Biomaterial Database

Systematic patient-dose errors for 4- and 10-MeV microwave linear accelerators associated with rectangular collimator settings. 1978

R F Moyer

Systematic patient-dose errors relating to standard equivalent-square approximations and movable collimator-exchange effect were evaluated for rectangular fields of photon beams from 4- and 10-MeV microwave electron accelerators (Varian Clinac 4 and Clinac 18). Errors approached 2.5% at nominal treatment depths for highly elongated rectangular fields. The collimator-exchange effect should be considered when (a) evaluating ionization-chamber stem effect, (b) specifying relative output factors for rectangular fields, and (c) evaluating equivalent-square-field algorithms.

UI	MeSH Term	Description	Entries
D011878	Radiotherapy	The use of IONIZING RADIATION to treat malignant NEOPLASMS and some benign conditions.	Radiotherapy, Targeted,Targeted Radiotherapy,Radiation Therapy,Radiation Therapy, Targeted,Radiation Treatment,Targeted Radiation Therapy,Radiation Therapies,Radiation Therapies, Targeted,Radiation Treatments,Radiotherapies,Radiotherapies, Targeted,Targeted Radiation Therapies,Targeted Radiotherapies,Therapies, Radiation,Therapies, Targeted Radiation,Therapy, Radiation,Therapy, Targeted Radiation,Treatment, Radiation
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
D006801	Humans	Members of the species Homo sapiens.	Homo sapiens,Man (Taxonomy),Human,Man, Modern,Modern Man
D013819	Thermoluminescent Dosimetry	The use of a device composed of thermoluminescent material for measuring exposure to IONIZING RADIATION. The thermoluminescent material emits light when heated. The amount of light emitted is proportional to the amount of ionizing radiation to which the material has been exposed.	Dosimetries, Thermoluminescent,Dosimetry, Thermoluminescent,Thermoluminescent Dosimetries