Physics Athens 2016

IMRT – the tongue and groove effects

Nominal leaf edge

100 MU

97 MU*

=

Tongue&Groove Effects MLC

97 MU*

The ‘tongue-and-groove’ effect may potentially be of significance as under-dosage occurs between two adjacent leaf pairs due to the fact that the region in between is always covered by the tongue, or the groove or both.

*3% leakage through MLC