Purpose: The purpose of this study is to compare the performance of three 3-dimensional radiotherapy treatment planning systems (TPS) in terms of user-friendliness and dosimetric accuracy.

Methods: A scale type questionnaire, which contained 129 items under 13 aspects of the TPS, was used to collect opinions from users from three different institutions with regards to the user-friendliness. The assessment of dosimetric accuracy was carried out by comparing the measured dose values with those calculated by the TPS under 18 different irradiating and phantom set-up conditions.

Results: Eleven respondents completed the questionnaires for each TPS. Our study indicated that the Varian CadPlan was outstanding in the plotting and network transfer of treatment plans to other workstations, the CMS Focus performed better in the construction of treatment aids, and the ADAC Pinnacle in the outlining, modification of field parameters, control of graphics and normalization of dose. In terms of dosimetric accuracy, the measured and the calculated data for the 3 TPSs showed fairly good agreement. Except for the field with median block, in which the Focus presented with the best result, the differences in other irradiating conditions were not obvious with the percentage dose deviations within ±3%.

Conclusion: In conclusion, for the 3 TPSs evaluated, each had its own strengths and weaknesses, and no TPS was superior in all test conditions.