IMRT 2018

IMRT audit results

• Dose-determination audits with anthropomorphic phantoms show, in the target

volume, an agreement between different centres of: – About 3% (1 standard deviation) for 3D-CRT – Up to 8% (1 standard deviation) for IMRT

• 30% of clinics failed to deliver correct IMRT H&N plans (7%/4 mm) according to Ibbot et al. (IJROBP 2008), due to:

– Incorrect output factors and percent depth dose data – Inadequate modeling of the penumbra at MLC leaf ends – Incorrect application of QA calculations or measurements – Inadequate QA of multi-leaf collimator – Incorrect patient positioning – Errors in treatment-planning software

06/06/2018