Biomaterial Database

Effects of extended SSD on electron-beam depth-dose curves. 1994

C B Saw, and T Pawlicki, and L J Korb, and A Wu

Division of Radiation Oncology, Robert C. Byrd Health Sciences Center, West Virginia University, Morgantown 26506.

The effects of extended source-to-surface distance (SSD) on the electron-beam depth dose curves were examined for five electron beam energies ranging from 6 MeV to 20 MeV. The depth dose curves were measured with the water phantom surface set at 100 cm, 110 cm, and 120 cm from the source. Except for the dose in the build-up region, negligible depth dose curve changes due to extended SSD were observed for electron energies less than or equal to 12 MeV. For electron beams greater than 12 MeV, the percent surface dose decreases and, additionally, the depth of maximum dose shifts deeper into the phantom as the SSD increases. Changes in the rapid falloff region of the depth dose curves were apparent only for the higher energy electron beams, in particular 20 MeV. Extended SSD has no observable effect on the tail portion of the depth dose curves. As such, the energies of the electron beams are not changed significantly by increasing the SSD.

UI	MeSH Term	Description	Entries
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
D011874	Radiometry	The measurement of radiation by photography, as in x-ray film and film badge, by Geiger-Mueller tube, and by SCINTILLATION COUNTING.	Geiger-Mueller Counters,Nuclear Track Detection,Radiation Dosimetry,Dosimetry, Radiation,Geiger Counter,Geiger-Mueller Counter Tube,Geiger-Mueller Probe,Geiger-Mueller Tube,Radiation Counter,Counter Tube, Geiger-Mueller,Counter Tubes, Geiger-Mueller,Counter, Geiger,Counter, Radiation,Counters, Geiger,Counters, Geiger-Mueller,Counters, Radiation,Detection, Nuclear Track,Dosimetries, Radiation,Geiger Counters,Geiger Mueller Counter Tube,Geiger Mueller Counters,Geiger Mueller Probe,Geiger Mueller Tube,Geiger-Mueller Counter Tubes,Geiger-Mueller Probes,Geiger-Mueller Tubes,Probe, Geiger-Mueller,Probes, Geiger-Mueller,Radiation Counters,Radiation Dosimetries,Tube, Geiger-Mueller,Tube, Geiger-Mueller Counter,Tubes, Geiger-Mueller,Tubes, Geiger-Mueller Counter
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
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