A new clinical teaching, learning and assessment strategy for radiotherapy and diagnostic imaging undergraduates was developed by action research. Outcome-based competencies were used together with other strategies to progress students' learning through successive levels with the aim of developing essential and desirable attributes of the respective professions. The planning team consisted of academic and clinical staff resulting in a shared project. Specific outcomes for each profession were devised by subgroups of the original team. The radiotherapy scheme implemented formative staged outcomes and the report focuses mainly on this strategy. Evaluation reveals that discriminations can be made at an early stage between those students achieving and those who are not. Highlighting specific areas for improvement allows opportunities for remedial work and creation of individual action plans. Key clinical staff underwent specific training to facilitate students' development and act as effective gatekeepers to progression. Recommendations for further research are to survey graduates now in employment to investigate how well they feel the scheme has fitted them for practice. There is also the potential to survey those who left the course prior to completion to discover if the scheme has helped to develop transferable skills for life long learning.

When preparing radiation treatment, the prescribed dose and irradiation geometry must be translated into physical machine parameters. An error in the calculations or machine settings can negatively affect the intended treatment outcome. Analysing incidents originating in the treatment preparation chain makes it possible to find weak links and prevent treatment errors. The aim of this work is to study the effectiveness of a multilayered error prevention system by analysing both near misses and actual treatment errors.

The system utilised in this centre has primary and secondary checking as two layers of independent calculation-checking. We studied near misses as well as the actual errors which were not picked up by these pre-treatment checking procedures over a year (5154 treatment plans). Furthermore, the primary checking was studied in more detail over three years (15,386 treatment plans) to increase the statistical accuracy.

For each reported actual treatment error originating in the treatment preparation chain, 13.8 near misses were found by primary and secondary checking and thereby prevented from becoming actual errors. The total frequency of near misses was 34.4 per 1000 treatment plans. The primary checkers reported 23 types of errors for manual treatment plans (without dose distribution) and 30 types of errors for computer plans. Computer plans also showed a near miss rate that was 42% higher than for manual plans. The high ratio of near misses per actual error demonstrates an effective error prevention system, independent of the quality of the initial treatment preparation. Complex treatment plans were shown to be particularly error-prone, thereby requiring extra vigilance when checking.

Equivalent Uniform Dose (EUD) has been proposed as a means of comparing treatment plans which include large PTV dose heterogeneity. Moreover, it has been suggested that EUD is insensitive to the underlying cell survival model parameters used in its calculation, and that arbitrary values might be used. This dependence of EUD on radiobiological parameters has been studied using different cell survival models (exponential and linear quadratic) and a range of artificially generated and clinical (lung and prostate) treatment plans. EUD was found to be strongly dependent on the variable SF2, but not on α/β, or number of fractions. When clinical treatment plans were ranked in order of EUD, a dependence of rank order on SF2 was observed, suggesting that arbitrary SF2 values are not appropriate for treatment plan evaluation. These results suggest that tumour specific SF2 values should be used for EUD calculation, and this is discussed.

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.

Background and purpose: Due to the increased complexity of the radiotherapy process in recent years, many QA procedures have been introduced to improve the quality of the treatment preparation and the treatment delivery. Most of these procedures give no direct information on the efficiency of the overall process in the radiotherapy department. It is quite evident that the frequency of errors will affect the efficiency of the process (for instance manpower to solve the detected problems), but also affect more generally the patients' experience.

Material and methods: To make some objective assessment of the erroneous entries in the process of radiotherapy, a pilot study was initiated to report all problems during a period of 2 months on a dedicated QA form. By registration of these errors, the QA group could trace the main sources of the decrease in efficiency and increased waiting time for patients.

Results and conclusions: For 46% of the patients during the two months at least one QA forms was filled in. With these QA forms 198 erroneous entries including 33 erroneous treatments were reported. Regarding the origin of the problems, the majority (60%) were generated in the planning process, while 56% of the errors were detected at the treatment unit before or during delivery of the first fraction. In total 461 actions were undertaken to recover all the reported errors. This generated time delay for 145 patients. Extrapolating these results to a year, a 0.7 full time equivalent person is spent to recover these errors, while the total patient population waits for about 140 hours. Corrective actions have been undertaken to optimise the overall process.