Radiotherapy Staff Research Articles

2327: A Randomized Cross-Over Study Comparing two Immobilization Devices for the Treatment of Prostate Cancer Patients Using Megavoltage CT Scanning To Evaluate Setup Accuracy

2327: A Randomized Cross-Over Study Comparing two Immobilization Devices for the Treatment of Prostate Cancer Patients Using Megavoltage CT Scanning To Evaluate Setup Accuracy

A graphical user interface for an electron monitor unit calculator using a sector‐integration algorithm and exponential curve‐fitting method

A new electron monitor unit (MU) calculator program called “eMUc” was developed to provide a convenient electron MU calculation platform for the physics and radiotherapy staff in electron radiotherapy. The program was written using the Microsoft Visual Basic.net framework and has a user‐friendly front‐end window with the following features: (1) Apart from using the well‐known polynomial curve‐fitting method for the interpolation and extrapolation of relative output factors (ROFs), an exponential curve‐fitting method was used to obtain better results. (2) A new algorithm was used to acquire the radius in each angular segment in the irregular electron field during the sector integration. (3) A comprehensive graphical user interface running on the Microsoft Windows operating system was used. (4) Importing irregular electron cutout field images to the calculator program was simplified by using only a commercial optical scanner. (5) Interlocks were provided when the input patient treatment parameters could not be handled by the calculator database accurately. (6) A patient treatment record could be printed out as an electronic file or hard copy and transferred to the patient database. The data acquisition mainly required ROF measurements using various circular cutouts for all the available electron energies and applicators for our Varian 21 EX linear accelerator. To verify and implement the calculator, the measured results using our specific designed irregular and clinical cutouts were compared to those predicted by the calculator. Both agreed well with an error of ±2%.PACS number(s): 87.53.Fs; 87.53.Hv; 87.66.‐a

Information giving procedures for patients having radiotherapy: a national perspective of practice in the United Kingdom

Purpose : The study aimed to survey information-giving procedures in United Kingdom radiotherapy departments. There was a dual focus to the work. A general look at the process and procedures involved in giving information to patients, and an enquiry into the availability of information to patients whose first language is not English.Methods : Superintendent radiographers in United Kingdom radiotherapy departments (n=63) were sent a self-completion questionnaire which included questions on key demographic variables.Results : Thirty-two questionnaires were returned. Three exclusions from analyses, due to incomplete data, gave a sample size of 29. Data were analysed using Statistical Package for Social Scientists (SPSS) . In almost all departments information about radiotherapy to patients was widely available, except for patients whose first language is not English. Departments in inner-city settings provided written information in a variety of languages other than English more often than others (P=0.003). For these patients interpreters were available but only a small number of responders reported using formal interpreter services. A third of the departments provided a formal telephone-based sypport system but the majority offered unofficial or informal telephone-based support systems, most usually in working hours only.Conclusions : The practice of giving information about radiotherapy to English speaking patients is generally sound. Patients who do not speak or read English are not likely to receive the same high level of service with regard to written information, and for many of these patients professional interpreter services are unavailable. Patient support is often given via the telephone but most generally as an unplanned disruption to the other work of radiotherapy staff.

A Quality Assurance Network in Central European Countries: Radiotherapy Infrastructure

A survey of the infrastructure in radiotherapy centres in three Central European countries has been performed as a first step in the development of a quality assurance network. Data concerning radiotherapy equipment, staff and number of patients treated in most of the radiotherapy centres from Czech Republic, Poland and Hungary were collected at the beginning of 1994. Equipment data have shown that 35% of 182 treatment units are conventional x-ray units, 35% 60Co units, 19% linear accelerators, 7% 137</supCs units and 4% betatrons. About 47% of high energy units are older than 12 years and about 20% older than 21 years. An important number of centres still have no simulator which would constitute an important handicap to carry out adequate radiotherapy. The number of treatment planning systems has also been registered; 44% being PC-based systems with locally developed software. Large variations are observed in the number of patients treated per year, per high energy unit, but 12/47 centres treat more than 700 patients per year and unit. On the average, staffing seems adequate in numbers though there are wide variations. The main limitation of radiotherapy infrastructure in the Central European countries is the low number of linear accelerators and simulators and the advanced age of therapy units. </abs>

3. 放射線治療の患者整位における誤差分析(放射線治療システムにおける QA)

To reproduce and keep the position of field alignment decided during treatment planning, it is necessary to immobilize and position the patients with exactness. Until now portal films have been used to verify and control the accuracy of fields alignment. For the study of deviation of field alignment, this article reviews the data published over the 10 or so years, and analyzes the extent of displacement from an intended position. From this analysis, it was shown that the extent of systematic and random errors had been at the same level. Therefore, it is effective in excluding systematic errors during the first session of radiotherapy, and then, it is expected to improve the uncertainty during the localization of fields. When a biteblock and plastic cast are used during patient setup, the extent of errors obviously decreased. Recently, electronic portal imaging devices are becoming available for radiotherapy. In this paper, advantage of these was discussed regarding use for patients setup. It is also important to improve the environment of radiotherapy (units and staff) as well as quality control. In Japan, especially, there are many problems with respect to radiotherapy staff. It is of urgent necessity in solving this problem.

Neutron and gamma ray measurements carried out around a Varian Clinac 2500 linear accelerator

Auckland Hospital, New Zealand, has recently installed a Varian Clinac2500 linear accelerator. This unit is capable of producing 24 MV peak photon energies. It is well known (Fox et al, 1977; Ing et al, 1982; Palta et al, 1984) that such photons are capable of producing neutrons via a photonuclear reaction. The sources of such neutrons from this accelerator have been described (LaRiviere, 1985). In this study a survey was carried out around this new installation to observe some of the characteristics of the neutrons produced, and to assess likely radiological hazards to radiotherapy staff. Equipment and methods Equivalent neutron dose was measured using an Alnor neutron dose rate meter (rem-meter) model 2202D. Remote pulse counting was carried out using an Elscint model INS-30 nuclear spectrometer. The manufacturer of this unit claims that the detector exhibits 200 R/h gamma ray discrimination. Initially this would appear satisfactory for carrying out a survey, but owing to the fact that linear accelerators are operatedin pulsed mode, peak leakage and scatter photon dose rates within the treatment room could well exceed 200 R/h. This was confirmed by operating the accelerator in 6 MV photon mode (i.e. producing no expected neutrons) and showing that the neutron meter did in fact respond. However, in the entrance maze to the treatment room the scattered X-ray dose rate was attenuated sufficiently so that it was not contributing to detector response.

Quality assurance control in the EORTC cooperative group of radiotherapy: 1. Assessment of radiotherapy staff and equipment

A quality control study was carried out by the EORTC Cooperative Group of Radiotherapy. From January 1982 to December 1984, 17 institutions were visited by a group of "experts" in radiotherapy and radiation physics. The evaluation included three steps: a comparison of megavoltage units, technical and staff environment, and data present in clinical and radiotherapy charts for each center; radiation physics calibration of photon and electron beams; and radiation physics measurements on a stimulated clinical case using an Alderson Rando anatomical phantom. This paper presents the results of Part 1. The results of Parts 2 and 3 will be analyzed in separate papers. Large variations were observed in the number of patients treated per year, per radiotherapist, per radiation physicist and per technician. On average, 400 patients were treated per year per megavoltage unit, but 8/17 centers treated more than 500 patients per unit per year. The number of simulators was suboptimal in 12/17 centers. These observations were summarized by a workload and staff index, and this index shows that in 5/17 centers major problems are present which make it difficult to comply with all the requirements of EORTC protocols. The quality of work-up regarding tumor extension was considered to be satisfactory in all centers. Dental care in patients irradiated to the head and neck was not well organized in 5/17 centers. Interaction between CT scan and dosimetry treatment planning could be improved in most centers and this should be one of the primary objectives of future quality control.

Wedged fields of the philips treatment planning system

With reference to Dr. Van Overbeek's letter (1979). Whilst accepting that it would be a fairer check on the beam accuracy to compare computed wedged curves with plotted wedged curves, it needs to be re-emphasised that in all our routine TPS planning the wedged fields have to be called from the computer as “compensators” in order to maintain the wedge normalization convention with which all the radiotherapy staff are familiar.