About the Treatment
VMAT is a modified type of IMRT technique. During treatment, the radiotherapy machine rotates around the patient delivering focused beams of radiation to cancer while reducing risk to critical structures. The machine continuously reshapes the intensity of the radiation beam thus making it very accurate along with reducing the treatment time while providing a lower dose of radiation.
VMAT differs from IMRT because it delivers the dose to the whole volume, rather than slice by slice. VMAT is used for tumours that are adjacent to critical structures such as a tumour wrapped around an organ.