SBRT 2016

Recently… New identical Linac… • A new Linac is introduced, identical to an existing Linac. • Linac modelled in TPS for FF beams based on measurement data from existing linac. However, profiles were from FF beams but pdds from FFF beams! Not clear yet whether due to auto copy mistake (software error) or manual copy mistake • After 1 year this error was discovered by scientific research measurements. • Absolute dose deviations were 3-5%.