ON THE QUALITY OF TREATMENT PLANNING SYSTEMS IN RADIATION-THERAPY

Purpose: To assist in the design of quality assurance activities of 3D treatment planning systems (TPSs), a postal survey has been carried o ut, addressing TPS users on quality characteristics and their relative importance in clinical routine planning. Material and Methods: The ap proach as described in ISO/IEC 9126 has been used to analyze TPS quali ty. Both TPS quality characteristics and how these may be used to esta blish a quality model are included. A questionnaire on ranking of thes e TPS quality characteristics has been sent out to the German DEGRO me mbers in February 1997. Results: By the end of July 1997, 90 individua l assessments (of 45 physicists, 35 physicians, and 10 radiographers) had been collected. On an importance scale from 1 (very important) to 6 (unimportant), weight factors of 1.71 (portability), 2.84 (maintaina bility), 3.18 (efficiency), 3.85 (usability), 4.52 (functionality) and 4.90 (reliability) have been determined from the data. From user sati sfaction data also obtained from the questionnaire responses, baseline quality indices could be established from the quality model for the R TPs Cadplan, TMS Helax, and Voxelplan. Conclusion: The responses highl ight the need for TPS quality assurance at the same time along the lin es of safety-related, research-oriented, and interactive end-user soft ware systems in radiotherapy treatment planning. Quality assurance act ivities must take this into account. Their effect can be monitored by using quality indices as derivable from the established quality model.