Volumetric intensity modulated arc therapy (VMAT) is a form of intensity modulated radiotherapy (IMRT) that delivers radiation in the form of an arc. VMAT uses the same basic methods as IMRT, such as intensity modulation and inverse planning, except that it is applied with arc-shaped motion around the treatment target volume.

Treatment In order to give the treatment that will provide the most appropriate dose distribution in the target to be treated according to the IMRT application, one or more full or half arc movements can be treated during the treatment. A major advantage of VMAT implementation is that it can often be much faster for a single arc or even a multiple arc plan than a fixed field IMRT application. This reduction in treatment time may be an important advantage in the destruction of tumor cells radiobiologically.