Quality Control (QC) of Simulators and CT scanners and some basic QC methods for Treatment Planning

This report is partially superseded by NCS report 15, Quality assurance of 3-D treatment planning systems for external photon and electron beams.

Please note that a new version should occur before 2020.

A questionnaire on quality control (QC) procedures of simulators and computed tomography (CT) scanners was completed by all radiotherapy institutions in The Netherlands. In addition, an inventory was made of basic methods for QC procedures for treatment planning systems. Large variations were observed in time dedicated to QC for simulators, i.e. between 2 and 20 hours per month per simulator. A great similarity exists in the frequency distributions of checks on the most important mechanical parameters of simulators and linear accelerators. Most of the CT scanners used for treatment planning are located at the departments of diagnostic radiology within the same institute. For this reason less than half the number of radiotherapy departments perform QC of CT scanners. The 21 radiotherapy institutions operate 11 different types of treatment planning systems. QC of treatment planning systems after acceptance for clinical use is mainly aimed at reproducibility of the calculation process of the system. The QC aspects are related to the integrity of software and data files, actual and implemented beam data, digitiser and plotter, transfer of CT data and correlation of CT numbers with electron densities. Finally, some patient specific procedures are presented. The data obtained from the questionnaires were compared with recommendations given in national and international reports on QC of simulators, CT scanners and treatment planning systems. From these combined data, a set of minimum requirements has been formulated. The present report contains over 30 test procedures including test frequencies and action levels. 

https://doi.org/10.25030/ncs-011