Dosimetric Consequences of Intrafraction Prostate Motion

Although significant motion can be observed during individual fractions, the dosimetric consequences are insignificant during a typical course of radiotherapy (30-40 fractions) with CTV-PTV margins of 2 mm or greater provided that the Calypso system is applied for pretreatment localization. Further reduction of the margin is possible if intrafraction realignment is performed.