To validate the model-based 3D dose calculation performed by the COMPASS system, and to evaluate the use of the combination of model-based and measurement-based 3D dose determination for clinical QA purposes.

To quantify the dosimetric accuracy of the COMPASS correction kernel method, and to determine its ability to detect dose delivery errors caused by MLC leaf mis-positioning.

The main objective of this study was to make the transition from a film (2D) based pre-treatment IMRT / IMAT QA into a more efficient and clinical relevant method of verification by reconstructing the dose directly in the patient CT using the COMPASS system. The evaluation of the reconstructed dose includes …

This study explores the capability of the COMPASS system (IBA Dosimetry, Germany) to detect leaf positioning errors of a high resolution MLC with 4mm leaf width using a lower resolution (7.62mm detector spacing) 2D matrix of ionisation chambers