Basic Clinical Radiobiology 2017

Planning technique of craniospinal irradiation

• IMRT: The inferior edges of the lateral brain fields and the superior edge of the lower posterior spine field are manually designed with long, smooth dose gradients by IMRT field-in- field (FIF) techniques.

• More robust for setup errors • 1%/mm dose gradient in junction • 1 cm shift will result in 5-10% dose difference