VMAT patient QA

Use your portal imager as absolute dosimeter to verify VMAT plans following these steps:

  • Replace patient 3D model with water phantom and reset gantry angles to zero for dose calculation
  • Calculate verification plan using YOUR CLINICAL dose calculation algorithm
  • DICOM export dose plane at dmax as a reference matrix
  • Deliver the VMAT plan normal way while acquiring integrated image
  • Compare calculated versus acquired dose matrices using Epiqa

Benefits of using Epiqa for VMAT plan QA:

  • Simple QA plan preparation
  • Instant detector preparation for measurement – just deploy portal imager arm
  • Easy QA plan delivery – can be performed by therapist
  • Fast data export – export only 4 DICOM objects
  • Quick results evaluation. In just few minutes user can print final protocol for approval
  • The method verifies not just the delivery device but also TPS performance
  • Supports also FFF-VMAT plans (more about FFF beams)

Example of evaluation of RapidArc plan using FFF beam (18 Gy/fraction, 10 MV FFF, 2400 MU/min):

FFF RapidArc patient QA

Related references:

Using EPIQA for the verification of FFF-RapidArc Plans on the TrueBeam

Fredh A. et.al: Patient QA systems for rotational radiation therapy: A comparative experimental study with intentional errors, Med. Phys. 40, 031716 (2013)

White paper: Hrbacek J.: Verification of RapidArc® plan using EpiqaTM

Last update on 13. February 2018