Physics Athens 2016

IMRT – the tongue and groove effects

• For one intensity-modulated treatment field, the maximum tongue-and-groove effect could be up to 10%. • For an IMRT treatment with multiple gantry angles, the tongue-and-groove effect 1-2 % for typical clinical cases. • Tongue and groove effects can be minimised by applying collimator twists on the beams.

J Deng et al. Phys. Med. Biol. 46 : 1039–1060, 2001.