Functional Magnetic Resonance Imaging (fMRI) permits the non-invasive mapping of brain activation during some specific stimulation. This paper demonstrates the application of fMRI for including cortical activation into a treatment plan produced on our commercial treatment planning system (CMS XiO™). A patient with an intracranial tumour near the motor cortex was studied on a 1.5 Tesla GE Signa scanner. Images from conventional MRI, used to define the planning target volume (PTV), and from fMRI, used to define the organ at risk (OAR), were transferred to the treatment planning system. Three plans were generated with similar treatment intent and compared to assess the dose given to the OAR. These were: 1. a conventional plan; 2. an IMRT plan optimised to cover the PTV and; 3. an IMRT plan optimised to additionally spare the OAR. Results show that 21% of the motor cortex (OAR) receives 90% of the prescription dose when planned conventionally. This is reduced to 9% when IMRT is used, and to 2% when fMRI data is included. This novel approach can be extended to other functional areas of the brain, giving rise to a more conformal avoidance radiotherapy technique, which may help to preserve patient's quality of life.

Purpose: Radiation techniques employed for breast cancer must be efficient as well as effective in order to minimise waiting lists. Protocol restrictions, or the technical application of treatment, may influence planning and treatment times as radiographers follow departmental policies. A national survey of UK radiotherapy centres was undertaken to establish trends in waiting times for breast cancer irradiation; and to investigate relationships of waiting times with the deployment of equipment and personnel and technical procedures adopted.

Method: A questionnaire was posted to the Head of Radiotherapy Services and a Clinical Oncologist with an interest in breast cancer in the radiotherapy centres in the UK. Survey questions investigated a number of issues, including the number of breast patients planned per week; protocols chosen; average treatment and planning times; levels of personnel and equipment; and the population served.

Results: A total of 53 centres were contacted, of which 51 centres responded to some aspect of the survey (96%). Average waiting times for treatment fluctuated from 1 to 7 weeks and maximum waiting times of 11 weeks were reported. Variation in clinical practice was found, including procedure times and the number of radiographers employed per linear accelerator. A multiple regression analysis indicated that a combination of equipment levels, simulation times, and the number of breast contours taken best predicted the average waiting time for breast treatment.

Conclusion: Waiting times reported were influenced by a combination of levels of equipment available and protocols adopted.

This paper explores the views of men who have experienced external beam radiotherapy as part of their treatment for prostate cancer. Using three focus groups, the study aimed to explore men's experience of radiotherapy. However it soon became clear that it is not possible to disentangle the experience of radiotherapy from that of the whole cancer journey. Four themes emerged from qualitative analysis of the data, namely, making decisions (feeling prepared and informed), the experience of radiotherapy, side effects of treatment and sources of support.

The findings indicate that health care professionals involved in radiotherapy treatment delivery need to understand and maintain sensitivity to the physical and emotional impact of the men's experience prior to radiotherapy in addition to those experienced during radiotherapy. In order to raise awareness and understanding of whole experience from the men's perspective, it is suggested that feedback of patient experience should become an integral part of radiotherapy department activity.

This paper is an extract from a wider study that explores the experience of men undergoing brachytherapy and external beam radiotherapy.

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.

This work describes the feasibility of using a polymer-based tissue equivalent gel for measuring radiation doses in situ. The gel is based on the MAGIC formulation thereby enabling it to be manufactured under normal atmospheric conditions. Its composition has been altered to achieve a similar sensitivity to the more widely used, but technically more difficult to produce, PAG gels. Irradiation of the gel material causes polymerisation of the molecular structure resulting in a shortening of transverse relaxation time (T2), which can be imaged using Magnetic Resonance Imaging (MRI). This work calibrates the radiation response in terms of transverse relaxation rate (R2) and uses this information to provide absolute dose verification in a separate gel, which has been previously irradiated to a known configuration. Results demonstrate that this technique is able to verify radiation doses to within a few percent of delivered intent in three dimensions and with high spatial resolution. This work may be followed by anyone with an interest in the quality assurance of advanced conformal radiotherapy delivery methods.

The concept of intensity-modulated radiotherapy is now familiar to everyone working in radiotherapy in the UK. To date however, the majority of UK radiotherapy departments have yet to offer this technique clinically. Implementation of IMRT represents a significant change in practice from the delivery of conventional or conformal treatment, requiring careful planning and a full understanding of the issues and new technology involved.

This paper provides a review of the stages involved in the IMRT process; from localisation and immobilisation through inverse treatment planning and quality control to delivery and verification, highlighting those aspects that represent a significant change in practice or approach.

Current and future developments that are expected to enhance or provide alternatives to IMRT, such as developments in radiobiological modelling, functional imaging, tomotherapy and proton therapy are discussed.

The development of intensity modulated radiotherapy (IMRT) has allowed the delivery of concave dose distributions. Planning studies have demonstrated the potential clinical benefit of IMRT in the treatment of the prostate and pelvic nodes in patients with advanced prostate cancer. As a consequence, IMRT was clinically implemented in the Royal Marsden NHS Trust in September 2000, using Elekta Sli series linear accelerators and NOMOS Corvus v3.0 planning system. As a relatively new treatment procedure in the United Kingdom, the clinical implementation involved developing appropriate quality assurance and verification procedures as well as training staff. This paper describes the practicalities of implementing IMRT into the routine workload of the radiotherapy department.

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.

UK Radiotherapy Departments have been surveyed to establish the current level of provision of intensity-modulated radiotherapy (IMRT) and its expected growth in the next 2 to 5 years. At the time of writing, nine UK Departments have implemented IMRT, providing a national capacity of approximately 20 new patients per month. By 2005, a further nine Departments expect to have implemented IMRT. As confidence and experience of IMRT grows, streamlining of quality control (QC) and the development of class solutions for inverse treatment planning are expected to significantly reduce the preparation time required for each patient and so increase patient capacity in all Departments.

Staff training requirements, extra workloads in treatment planning and QC, identification of inverse planning parameters and current limitations of inverse treatment planning systems were identified as the key learning points for Departments that have been through the implementation process. Obstacles identified as preventing early implementation include equipment availability, staff shortages and heavy clinical workloads limiting the amount of time available for implementation.

In recent years therapy radiographers, as one of the Allied Health Professions, have been subject to many initiatives, recommendations and professional and technical developments which have driven or encouraged them to increase their uptake of post-registration continuing education and professional development activities. These initiatives and drivers for change are diverse both in their source and in their degrees of influence and range from government legislation at a national level down to local initiatives. This paper identifies the main drivers affecting therapy radiographers with regard to these issues, evaluates their impact on the profession and discusses some of the barriers and limitations to the uptake of educational and CPD activities.

Several instruments have been used to measure absorbed radiation dose under non-electronic equilibrium conditions, such as in the build-up region or near the interface between two different media, including the surface. Many of these detectors are discussed in this paper. A common method of measuring the absorbed dose distribution and electron contamination in the build-up region of high-energy beams for radiation therapy is by means of parallel-plate ionisation chambers. Thermoluminescent dosimeters (TLDs), diodes and radiographic film have also been used to obtain surface dose measurements. The diamond detector was used recently by the author in an investigation on the effects of beam-modifying devices on skin dose and it is also described in this report.

The Board of Faculty of Clinical Oncologists and The Royal College of Radiologists published the first edition of explicit guidelines in 1996 for “the management of the unscheduled interruption or prolongation of a radical course of radiotherapy”.

The recommendations highlighted the significant detrimental effects on local tumour relapse rates in some cancer types, when the time taken to deliver a radical radiotherapy prescription is increased.

A national audit was carried out in February 2001, to establish compliance and trace ability of radiotherapy prescription delivery. The audit aimed to establish if local protocols are in place and if regular audit process took place to promote continuous improvement to treatment delivery compliance.

Sixty-four radiotherapy managers were invited to participate in the study, by completing a short questionnaire. A response rate of 74% was achieved.

The findings from the study indicated that the majority of radiotherapy centres within the United Kingdom have a protocol for the management of radiotherapy prescription compliance, where causes in non-compliance are documented. In contrast, a statistically significant number of radiotherapy department fail to monitor or evaluate causes of radiotherapy prolongation.

The author recommends, that, in order to reduce local tumour relapse rates, the use of a strategic, robust local and national audit system must be in place.

The second edition of recommendations for managing radiotherapy prolongation was published in 2002. The theme of strategic auditing remains high on the agenda.

Purpose: This paper describes our experiences of implementing systematic in vivo dosimetry at the Norfolk and Norwich Hospital and reviews the results of 2,254 entrance dose measurements made over a 17-month period.

Methods and materials: Entrance dose measurements using p-type diodes were performed on all new planned patients. The calibration procedure and correction factors applied are described. A 4% tolerance was applied.

Results: The results of all measurements indicated a small mean deviation from expected entrance dose of 10.77% and a standard deviation of 2.85%. 16.7% of all measurements exceeded the 4% tolerance with 9.2% exceeding a 5% level. The estimated overall errors for 578 treatments were calculated using the weighted averages of all beams. A narrower SD of 1.96% combined with only 4.8% of all treatments exceeding a 4% tolerance show that large deviations from a single field do not always translate into significant overall errors.

Conclusions: Global dosimetric accuracy was within clinically acceptable limits and variations between measured and expected doses were mainly attributable to factors affecting diode reading. A number of errors in calculating deviations and the inconsistent application of the protocol suggest the need for interfacing the diode system with software control.

The benefits of employing computed tomography (CT) into the planning process of radiotherapy has been well established over the last 20 years. The cross sectional images provide invaluable information that enable clinicians to plan patients treatment with confidence. More recently there has been the development of the CT-simulator (CT-sim), however its place in the clinical setting has still to be established.

One of the most anticipated questions is “will the CT-simulator replace the present conventional treatment simulator as a tool for simulation?” There appear to be tremendous reasons why it should, but there are also many issues that need to be addressed.

This discussions aims to critically assess the practical and technical aspects of the new technology, by means of reviewing published literature. The aim is to decipher whether its introduction into the planning process is realistic and appropriate for all radiotherapy patients, and whether it has the possibility to replace the treatment simulator.

Issues concerned with image production, simulation (virtual), planning, cost, quality assurance (QA) and patient criteria (i.e. radical and palliative patients) have been reviewed. The Study concludes that the CT-sim has the realistic possibility to dramatically improve the treatment intent of all radiotherapy patients. Although there are situations where the treatment simulator appears to supersede the CT-sim, there still appears to be a place for it within the planning process.

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.