EGS Application - Treating Cancer with Radiation
Now that you have learned about EGS, let's see one way EGS has been used in a "real world" application to improve radiation cancer treatments.
Medical Problem
Approximately one in eight people receives radiation treatment for cancer. Electron accelerators produce the x-rays used in these treatments. The first accelerator for medical use was built at Stanford in 1956. Today every major hospital has one of them.
A medical physicist needs a computer program to calculate radiation effects in the body and plan treatments. The problem is how to give maximum radiation dose to the tumor with minimum damage to healthy tissue.
The EGS Software Solves the Medical Problem
The "Electron-Gamma-Shower" (EGS) is now the most accurate method
available to calculate radiation effects in body tissue and
determine dosages. SLAC physicists originally developed the
EGS program to model the passage of radiation through particle
detectors. It has been "tuned" to match a wide variety of measured
effects, adapted in collaboration with the National Research
Council of Canada.
EGS uses the density and the locations of various tissue types in each patient's body in its calculations. Most body tissue has about the same density as water, but bones are twice as dense and lung tissue 1,000 times less dense. A model that treats all tissues alike would not do the job!
The EGS program is used as the "gold standard" to check whether simpler, faster, approximate calculation methods that are used by practitioners are doing the job accurately enough. As treatment techniques improve, more accurate calculations are needed.
Use the links below to learn more about how the EGS code has been used to improve treating cancer with radiation therapy.