Basic Treatment Planning

Errors in the radiotherapy chain (McKenzie et al., BIR 2003)

• Systematic errors : treatment preparation errors  Delineation errors 

Organ position and shape at time of localization  Phantom transfer errors

o Geometric imaging error (e.g. CT alignment laser errors) o Treatment planning system error (e.g. shielding blocks) o Linear accelerator geometry error (e.g. laser & coll. position)  Set-up error at time of localization  TPS beam algorithm error  Breathing positional error

• Random errors : treatment execution errors  Organ position and shape  Daily set-up error