Dual-energy linear accelerators (also referred to as high energy linear accelerators,) are capable of producing more than one photon energy. The British Journal of Radiology (BJR) supplement 11, also referred to as BJR11, initially defined a photon’s depth dose by a specific measurement. BJR 17, some eleven years later, modified that definition. The linear accelerator’s energy definition or energy selection for photon beams will vary based on which BJR definition is used. This can sometimes be confusing (other than to medical physicists).
|Photon Energies using the BJR #11 Definition||4MV||6MV||10MV||15MV||18MV||20MV||24MV|
|Equivalent Energies using the BJR #17 Definition||4MV||6MV||10MV||16MV||23MV||25MV||30MV|