Quality assurance in radiotherapy by identifying standards and monitoring treatment preparation

Background and purpose: Due to the complexity of the treatment preparation in radiotherapy, a number of errors go undetected until after the first tre atment session. Some of these errors could easily have been noticed before treatment if an objective filter existed in addition to human supervision. With this in mind, a conceptually novel extension to conventional quality a ssurance procedures was explored to create a global platform monitoring tre atment preparation by comparison with the existing local standards. Materials and methods: The feasibility of developing such a platform was ev aluated for a test case on a cohort of 202 patients having received breast irradiation. By statistical analysis of the treatment parameters, mean valu es and tolerance levels could be defined for most parameters based on the o bserved standard deviations. Useful correlations were traced providing us w ith a means to automatically track errors, the detection of which would oth erwise solely depend upon the alertness of the supervisor. Results and conclusions: Apart from its possibilities as a mere quality con trol tool, the platform, developed in the framework of EQUART (European Qua lity Assurance Program in Radiotherapy by Monitoring Treatment Preparation) , can be incorporated in the treatment preparation chain, providing standar d setup values for the simulation. A crucial achievement of EQUART lies in the fact that filtering out of errors occurs prior to treatment initiation. (C) 2000 Elsevier Science Ireland Ltd. All rights reserved.