Applied Radiation Biology and Radiotherapy (ARBR)
Teletherapy is clinically administered by the application of electro-magnetic radiation or electrons.
Electromagnetic radiation may be X-rays - radiation produced, when an accelerated electron hits a target.
- Contact therapy < 100 kV
- Superficial voltage ~ 100 kV
- Orthovoltage ~ 150 - 300 kV
- Megavoltage ~ 4 MeV - 25 MeV
or gamma rays - radiation emitted from radioactive elements or isotopes.
While Ra-226 and Cs-137 have been used as gamma emitters, the modern radiotherapy department frequently relies on Co-60 teletherapy machines which operate as megavoltage equipment.