In pre-treatment dose verification, low resolution detector systems are unable to identify shifts of individual leafs of high resolution multi leaf collimator (MLC) systems from detected changes in the dose deposition. The goal of this study was to introduce an alternative approach (the shutter technique) …

The objective of this study was to introduce a new iterative method to reconstruct multi leaf collimator (MLC) positions based on low resolution ionization detector array measurements and to evaluate its error detection performance. The iterative reconstruction method consists of a fluence model, a detector …

PURPOSE: Advanced radiotherapy treatments require appropriate quality assurance (QA) to verify 3D dose distributions. Moreover, increase in patient numbers demand efficient QA-methods. In this study, a time efficient method that combines model-based QA and measurement-based QA was developed; i.e., the …

The COMPASS system (IBADosimetry) is a quality assurance (QA) tool which reconstructs 3D doses inside a phantom or a patient CT. The dose is predicted according to the RT plan with a correction derived from 2D measurements of a matrix detector. This correction method is necessary since a direct reconstruction …

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