The role of the biomedical physicist in the education of the healthcare professions: an EFOMP project.

The role of the biomedical physicist in the education of the healthcare professions has not yet been studied in a systematic manner. This article presents the first results of an EFOMP project aimed at researching and developing this important component of the role of the biomedical physicist. A background to the study expands on the reasons that led to the need for the project. This is followed by an extensive review of the published literature regarding the role. This focuses mainly on the teaching contributions within programmes for physicians, diagnostic radiographers, radiation therapists, and the postgraduate medical specializations of radiology, radiotherapy, interventional radiology and cardiology. Finally a summary list of the specific research objectives that need to be immediately addressed is presented. These are the carrying out of a Europe-wide position audit for the role, the construction of a strategic role development model and the design of a curriculum development model suitable for modern healthcare professional education.

Count-rate analysis from clinical scans in PET with LSO detectors.

The purpose of optimising the acquisition parameters in positron emission tomography is to improve the quality of the diagnostic images. Optimisation can be done by maximising the noise equivalent count rate (NECR) that in turn depends on the coincidence rate. For each bed position the scanner records coincidences and singles rates. For each patient, the true, random and scattered coincidences as functions of the single count rate(s) are determined by fitting the NEMA (National Electrical Manufacturers Association) 70 cm phantom count rate curves to measured clinical points. This enables analytical calculation of the personalised PNECR [pseudo NECR(s)] curve, linked to the NECR curve. For central bed positions, missing activity of approximately 70% is estimated to get maximum PNECR (PNECR(max)), but the improvement in terms of signal-toz-noise ratio would be approximately 15%. The correlation between patient weight and PNECR(max) is also estimated to determine the optimal scan duration of a single bed position as a function of patient weight at the same PNEC. Normalising the counts at PNECR(max) for the 70 kg patient, the bed duration for a 90 kg patient should be 230 s, which is approximately 30% longer. Although the analysis indicates that the fast scanner electronics allow using higher administered activities, this would involve poor improvement in terms of NECR. Instead, attending to higher bed duration for heavier patients may be more useful.

Proposal for a patient database on cardiac interventional exposures for epidemiological studies.

Relatively high organ doses absorbed by patients in interventional cardiology suggest the opportunity to define these patients as a cohort to be followed forward in time in an epidemiological study of the cancer risks associated with exposure to low-dose ionising radiation. In this paper, the UNSCEAR 2000 Report risk estimates for the most exposed organs/tissues in cardiac interventional procedures are reviewed, as well as the critical features of such an epidemiological study that is anticipated to have an intrinsically low statistical power because of the low levels of risk and possible confounding factors. To overcome these limitations, data collected in different institutions can be combined provided that a common design and conduct are used for dose assessment. A minimum dataset to be collected on a patient basis is proposed that can be implemented routinely in most facilities. This data should be linked to the local patient information system in order to retrieve all the exposures of a given patient.

Image quality criteria in cardiology.

Image quality evaluation plays a key role in the process of optimisation in radiological procedures. Image quality criteria for cardiac cine-angiography were recently agreed as part of a European Research Project, and a scoring system based on these criteria has been developed to allow an 'objective' measurement of the quality of cardiac angiograms. Two studies aimed at the evaluation of the methodology have been completed, demonstrating that the method can be applied to cardiac images and translated into a scoring system that yields reproducible data. Based on the results of these studies, quality criteria have been further reviewed by DIMOND III panel and the updated version is presented in this paper.

Response of thermoluminescence dosemeters to beta radiation and skin dose assessment.

The response of a TL dosemeter to beta radiation is heavily influenced by the absorption of the radiation in the dosemeter thickness. As a consequence, the assessment of skin dose depends either on the execution of a calibration with a beta field of the same characteristics as that to be monitored or on the knowledge of depth-dose distribution in the dosemeter. Depth-dose distributions have been experimentally estimated for optically transparent dosemeters in a number of irradiation geometries and with sources of different configuration and energy. General algorithms based on the point-source function of Loevinger have been developed, by which the response of TL dosemeters can be evaluated and skin dose correction factors derived. TLD responses to beta radiation calculated by the present method are in sound agreement with other author's measurements. The dependence of beta ray absorption on the configuration of source and the source-to-detector distance has been picked up. Variations of source-to-detector distance as large as 30% of the maximum beta range account for differences up to 40% in the skin dose correction factors for a 200 mg cm-2 thick dosemeter. The proposed scheme results in a useful tool in skin beta dosimetry using multiple TLDs behind different absorbers. In practical applications thick dosemeters may be used properly only in well-known radiation fields. Conversely, the described method allows an acceptable estimate of the skin dose error.

Patient doses and risks from diagnostic radiology in North-east Italy.

A study has been conducted to asses the impact of radiological practice in 1983 in Friuli-Venezia Giulia, a region of North-east Italy with 1,250,000 inhabitants. The design involved three phases: a region-wide frequency survey; dosimetric measurements on patients in all public X-ray facilities; derivation of organ doses from those measurements. Frequencies by type, age and sex and values of the main technical parameters of radiological examinations are presented. Organ doses, effective dose equivalents and risk estimates are given for 14 selected examinations. The annual per-capita effective dose equivalent and the genetically significant dose are estimated at 0.848 mSv and 0.253 mSv, respectively. From these values, collective risks have been predicted by using the risk factors given in the International Commission on Radiological Protection Publication 26. The results indicate that 14 persons risk induced malignancies and 2.5 persons risk genetic detriment.

A comparison of diagnostic radiology practice and patient exposure in Britain, France and Italy.

Surveys have been conducted in Britain, France and Italy, using essentially the same techniques, to establish the level of provision of diagnostic radiology services, the frequency of X-ray examinations and examples of the radiation doses delivered to patients in each country. Different national strategies for conducting some types of X-ray examination and marked differences in the general availability of this aspect of health care indicate that the justification and optimization of medical exposures is not interpreted in the same way in these countries.

Staff dosimetry protocols in interventional radiology.

Assessment of effective dose (E) for workers performing interventional radiology is particularly problematic due to the conditions of partial body exposure, so very few estimates of E are found in the literature. Two simple algorithms (the Rosenstein-Webster and the Niklason algorithms) are available that combine the readings of two dosemeters, one worn under the protective apron and one on the neck outside the apron, to estimate E for the range of imaging conditions typical of medical fluoroscopy. The algorithms are reviewed and their suitability for estimating E for personnel performing interventional radiology is analysed by comparison with the most recent experimental data. It can be concluded that the Niklason algorithm's estimates are in better agreement with the experimental assessments of E.

Patient dose related to the complexity of interventional cardiology procedures.

In interventional cardiology (IC) the PTCA (percutaneous transluminal coronary angioplasty) procedure is the most frequent procedure with the highest dose to the patient. The procedure is usually performed by cardiologists having, in general, insufficient knowledge of radiation physics, radiation technology and radiation protection. The need for radiation protection is of paramount importance in this field of interventional radiology. Correlation between the complexity of PTCA procedure and irradiation parameters (fluoroscopy time, number of images and dose-area product--DAP) has been demonstrated. The presence of severe tortuosity and occlusion of > or = 3 months play a major role. Fluoroscopy time is better correlated with technical factors than DAP, which also includes the influence of patient size, collimation, operation modes, and X ray beam orientation. The number of acquired images is less correlated with the complexity of the PTCA procedure. A complexity index was conceived and procedures were divided into three groups, defined as: simple, medium and complex, which were significantly different in terms of patient dose.

A strategic development model for the role of the biomedical physicist in the education of healthcare professionals in Europe.

This is the third of a series of articles targeted at biomedical physicists providing educational services to other healthcare professions, whether in a university faculty of medicine/health sciences or otherwise (e.g., faculty of science, hospital-based medical physics department). The first paper identified the past and present role of the biomedical physicist in the education of the healthcare professions and highlighted issues of concern. The second paper reported the results of a comprehensive SWOT (strengths, weaknesses, opportunities, threats) audit of that role. In this paper we present a strategy for the development of the role based on the outcomes of the SWOT audit. The research methods adopted focus on the importance of strategic planning at all levels in the provision of educational services. The analytical process used in the study was a pragmatic blend of the various theoretical frameworks described in the literature on strategic planning research as adapted for use in academic role development. Important results included identification of the core competences of the biomedical physicist in this context; specification of benchmarking schemes based on experiences of other biomedical disciplines; formulation of detailed mission and vision statements; gap analysis for the role. The paper concludes with a set of strategies and specific actions for gap reduction.

A comprehensive SWOT audit of the role of the biomedical physicist in the education of healthcare professionals in Europe.

Although biomedical physicists provide educational services to the healthcare professions in the majority of universities in Europe, their precise role with respect to the education of the healthcare professions has not been studied systematically. To address this issue we are conducting a research project to produce a strategic development model for the role using the well-established SWOT (Strengths, Weaknesses, Opportunities, Threats) methodology. SWOT based strategic planning is a two-step process: one first carries out a SWOT position audit and then uses the identified SWOT themes to construct the strategic development model. This paper reports the results of a SWOT audit for the role of the biomedical physicist in the education of the healthcare professions in Europe. Internal Strengths and Weaknesses of the role were identified through a qualitative survey of biomedical physics departments and biomedical physics curricula delivered to healthcare professionals across Europe. External environmental Opportunities and Threats were identified through a systematic survey of the healthcare, healthcare professional education and higher education literature and categorized under standard PEST (Political, Economic, Social-Psychological, Technological-Scientific) categories. The paper includes an appendix of terminology. Defined terms are marked with an asterisk in the text.

Dependence of the linear model for the nerve compound action potential on the single fibre action potential waveform.

The linear model of the nerve compound action potential (CAP) depends on the assumed waveform for the single fibre action potential (SFAP). A general method has been developed to investigate the influence of the unknown features of the SFAP on the estimation of nerve fibre conduction velocity (CV) distribution. A SFAP waveform is considered consistent with the model and the experimental data if recorded and reconstructed CAPS fit and the distribution is physically meaningful. Experimental CAPS were monopolarly recorded using surface electrodes over the median nerve at the wrist. To fit the model, SFAP waveforms must satisfy some internal relationship. The most important feature is that the ratio between positive and negative areas of the SFAP is almost one and does not vary in different subjects and recording sites. Many SFAP waveforms fit the model, and the relative conduction velocity distributions may be very different. These must be regarded as conventional distributions. As for inter-subject comparison, the dependence of the method on the recording site has been reduced by choosing the place where stimulus intensity and relative motor response amplitude have given values. In this recording environment CV distributions of normal subjects can be properly compared using the same SFAP and deviations from normality evidenced.

[Templates for curietherapy of the oral cavity and their dosimetric use]. / I templates nella curieterapia del cavo orale e loro implicazioni dosimetriche.

Flexible 192Ir wire implants are commonly used for the treatment of some types of cancer in the oral cavity. A modified technique of plastic tubes is here presented which aims at correctly positioning the active wires with thin plastic templates. Possible sources of error are examined and their consequences on the dose distribution around the implant are analyzed. In most cases control dosimetry matches the provisions satisfactorily. It may be thus concluded that the use of templates allows good and reproducible results to be obtained in the brachytherapy of the oral cavity.

Clinical and technical determinants of the complexity of percutaneous transluminal coronary angioplasty procedures: analysis in relation to radiation exposure parameters.

Few data are available on the quantitative assessment of complexity (C), especially in relation to a patient's exposure to radiation. The relationship between several clinical (CFs), anatomic (AFs), and technical factors (TFs) versus fluoroscopy time (FT) was evaluated in 402 random percutaneous transluminal coronary angioplasty (PTCA) procedures. CFs were age, sex, single or multivessel disease, ejection fraction, and previous coronary artery bypass graft. AFs were assessed based on the American Heart Association / American College of Cardiology classification. TFs were multivessel PTCA, use of the double wire or double balloon technique, stenting, ostial stenting, bifurcation stenting, and intravascular ultrasonography. No CFs significantly influenced FT, whereas all AFs and TFs (except multivessel PTCA) did significantly influence FT. A scoring system was developed, and two complexity indexes (CI) were conceived, based on which the procedures were divided into three groups: simple, medium, and complex. The mean FTs were 471+/-289, 805+/-532, and 1,190+/-641 (P <0.0001), respectively. Total cine frame recordings were 1,119+/-572, 1,265+/-644 (P = 0.0355), and 1,418+/-785 (P<0.0001 vs. simple; P = NS vs. medium). The dose/area product measurement was 65.8+/-41.4, 93 +/-58.5 (P<0.0001), and 116.7+/-72.8 (P<0.0001 vs. simple; P = 0.00159 vs. medium), respectively. In our series, CI was directly related to AF and TF, but not to CF. Comparison of PTCA procedures and definition of appropriate FT should consider CIs.