Radiation Protection Dosimetry - Advance Access

INTER-COMPARISON STUDY OF THE POPULATION DOSE DUE TO GAMMA-RADIATION IN THE COAST OF NORTH SINAI BETWEEN RAFAH AND BIR EL-ABD AREAS

Seddeek, M. K., Sharshar, T., Badran, H. M. — 2009-06-26

This study compares the external dose due to the gamma-ray emitting radionuclides in various areas in North Sinai, Egypt. The whole area was divided into 10 regions. The average absorbed dose rates were evaluated for each region. It was found that Zaranik-protected area and Al-Massaid have the highest values of 72.7 and 57.2 nGy h^–1, respectively. The corresponding values of the remaining regions were <23 nGy h^–1. The mean annual effective dose equivalents for the four largest cities Rafah, El-Sheikh Zuwaied, Al-Arish and Bir El-Abd were 20.8, 18.8, 57.4 and 14.0 µSv, respectively. The results are compared with those from different areas in Egypt and in various countries.

ROD PHANTOM DIMENSIONS - DOES SIZE MATTER?

Brunzendorf, J., Ambrosi, P. — 2009-06-26

The international standard ISO 4037-3:1999 recommends a cylindrical polymethyl methacrylate rod phantom of 300 mm length and 19 mm diameter for the calibration of extremity dosemeters worn on the finger. No tolerances are stated. This paper investigates the influence of the actual rod phantom dimensions on the calibration results of finger dosemeters. For this purpose, thermoluminescence detectors were attached to rod phantoms of different size and irradiated at the PTB reference X-ray fields. Rod phantoms with a diameter of (19 ± 1) mm and a length of at least 100 mm can be considered to be equivalent for the calibration of finger dosemeters, since the variation in the calibration results is below the significance level of 1 %. The decrease in the response towards the edge of the phantom is negligible as long as the distance from the nearest edge exceeds 10 mm.

RAPPORTEURS' REPORT: WORKSHOP ON ETHICAL ISSUES IN DIAGNOSTIC RADIOLOGY

2009-06-24

This paper presents the summary reports of the session rapporteurs at the Workshop on Ethical Issues in Diagnostic Radiology. The summaries reflect the extent to which the topics discussed are well reflected in the papers presented in this proceedings.

WORKSHOP ON ETHICAL ISSUES AND JUSTIFICATION FOR HIGH-DOSE BUDGET-LIMITED PROCEDURES: A REPORT FROM AN EXPLORATORY AND CONSENSUS MEETING HELD AT HAIRMYRES HOSPITAL, SCOTLAND

Corbett, R. H., Malone, J. — 2009-06-18

This summary report presents aspects of work that was carried out as part of the European Commission SENTINEL Project (Safety and Efficacy for New Techniques and Imaging using New Equipment to Support European Legislation). It arises from the discussions at a workshop organised by the first author at Hairmyres Hospital, East Kilbride in September 2006. The second author facilitated the workshop and moderated the discussion. The paper notes key points from the discussion and provides some pertinent comments.

GAMMA AND BETA DOSES IN HUMAN ORGANS DUE TO RADON PROGENY IN HUMAN LUNG

Markovic, V. M., Krstic, D., Nikezic, D. — 2009-06-17

A great deal of work has been devoted to determine the effect of tissue damage produced by alpha particles emitted from radon and its progeny. ²¹⁴Pb and ²¹⁴Bi deposited in the human lungs emit beta particles followed by the gamma quanta, which cause smaller damage of tissue in comparison with alpha particles. Because of that, this type of irradiation has not been studied in detail. In this paper, doses from beta and gamma rays emitted by radon progeny ²¹⁴Pb and ²¹⁴Bi in the lungs have been calculated in all main organs and the remainder tissues of the human body. Human Oak Ridge National Laboratory phantom of adult male and female was used, where simulation was performed using MCNP-4B simulation code. The sources of beta and gamma radiations, namely, the radon progeny were located in lungs. Furthermore, dose conversion coefficients have been calculated.

INVESTIGATION OF THE NEUTRON CONTRIBUTION IN THE 6 MeV TO 7 MeV HIGH ENERGY PHOTON REFERENCE FIELD

Rottger, S., Heiske, A., Nolte, R. — 2009-06-17

In order to provide reference fields for the ionising radiation, PTB operates the ion accelerator facility. Referring to high energy photons, reference fields according to International Organization for Standardization 4037 series are produced. The neutron component of the 6–7 MeV photon field (R-F), which is produced by bombarding a CaF₂ target with protons with an energy of E_p = 2.7 MeV, is investigated in detail for the first time. Two discriminative methods are used to determine the yield for neutrons produced in the CaF₂ target.

RADIATION PROTECTION IN NEWER MEDICAL IMAGING TECHNOLOGIES: PET/CT

Banghart, D. — 2009-06-13

ETHICAL ISSUES FOR RADIOGRAPHERS: GENERAL OBSERVATIONS AND A PILOT QUALITATIVE STUDY

Gruppetta, E. — 2009-06-13

This paper is based on general observation arising from many years experience in managing and delivering radiography services in the health service. In addition, it presents the results of a pilot qualitative study based on unstructured interviews. The interviews were undertaken with a view to identifying the reasons for radiography that may not be well justified. The study was undertaken in the public and private sectors and many of the reasons are shared by both. The reasons for poor justification include: inadequate radiation protection education for referrers; avoidance of medical litigation; defensive medicine attitude by referrers and, in the private sector, pursuit of profit. The study provides a starting point for further more quantitative investigations that are clearly required in the area.

ENERGY AND FLUENCE CALIBRATION OF THE NEUTRON SPECTROMETER ROSPEC AT THE IRSN AMANDE FACILITY BETWEEN 70 keV AND 4.5 MeV

Benmosbah, M., Asselineau, B. — 2009-06-09

The ROSPEC device is a multi-detector system, which has been designed by Bubble Technologies Industries (BTI at Chalk River, ON, Canada) to assess neutron spectra, and hence neutron dose quantities, at workplace fields. It is made up of six gaseous proportional counters that detect neutrons via the elastic (n,p) scattering (four hydrogenous counters) and with the ³He(n,p)T reaction (two ³He-filled counters). Results of the calibration of a similar rotating spectrometer (ROSPEC) have been described by Rosenstock et al.⁽¹⁾. For energy and fluence calibration purposes, measurements were performed with the accelerator for metrology and neutron applications in external dosimetry (AMANDE) facility at the Laboratory of Neutron Metrology and Dosimetry (Institute of Radiation Protection and Nuclear Safety, IRSN, France). This facility provides monoenergetic neutron radiation fields from 2 keV to 20 MeV. Two kinds of experiments were carried out. First, the ROSPEC was used in its rotational mode for the ISO energies. Then, each detector was irradiated with all the available neutron energies, in a well defined position with the rotation of the device stopped. The energy values of the neutron beam were calculated using the TARGET code. A BC501-A liquid scintillation spectrometer provided the fluence values for energies beyond 1.2 MeV, a methane-filled SP2 counter from 800 keV to 1.4 MeV and an H₂-filled SP2 counter from 144 to 800 keV. Reference data for 70 keV monoenergetic neutrons were obtained using the IRSN Long Counter. Results showed that the ROSPEC device was in agreement with the absolute neutron fluences within 10%. Moreover, the new energy calibration factors are in good agreement with those derived by BTI.

DECONVOLUTION OF GAMMA-RAY SPECTRA OBTAINED WITH NAI(Tl) DETECTOR IN A WATER TANK

Rahman, M. S., Cho, G., Kang, B.-S. — 2009-06-05

Maximum-likelihood fitting by the expectation maximisation deconvolution method is presented to analyse gamma-ray spectra recorded using an NaI(Tl) detector for a water monitoring system. The applicability of the method was tested by deconvolving measured spectra taken using an industry standard 3'' x 3'' cylindrical NaI(Tl) detector in a model water tank with several calibration sources. The results show significant removal of the Compton continuum counts and efficient transfer of the counts into the corresponding photo-peaks. The peak-to-total count ratio and the number of counts in the photo-peaks in the deconvolved spectra increased approximately 4.67 and 5.29 times, respectively, compared with those of measured spectra taken using an NaI(Tl) scintillation detector in the case of ¹³⁷Cs.

DEFICIENCIES OF ACTIVE ELECTRONIC RADIATION PROTECTION DOSEMETERS IN PULSED FIELDS

Ankerhold, U., Hupe, O., Ambrosi, P. — 2009-06-01

Nowadays nearly all radiation fields used for X-ray diagnostics are pulsed. These fields are characterised by a high dose rate during the pulse and a short pulse duration in the range of a few milliseconds. The use of active electronic dosemeters has increased in the past few years, but these types of dosemeters might possibly not measure reliably in pulsed radiation fields. Not only personal dosemeters but also area dosemeters that are used mainly for dose rate measurements are concerned. These cannot be substituted by using passive dosemeter types. The characteristics of active electronic dosemeters determined in a continuous radiation field cannot be transferred to those in pulsed fields. Some provisional measurements with typical electronic dosemeters in pulsed radiation fields are presented to reveal this basic problem.

AN EVALUATION OF RADIATION EXPOSURES IN A TROPICAL PHOSPHOGYPSUM DISPOSAL ENVIRONMENT

Haridasan, P. P., Pillai, P. M. B., Tripathi, R. M., Puranik, V. D. — 2009-05-30

Environmental radiological aspects of phosphatic fertiliser production with particular reference to disposal of phosphogypsum at two sites in India are examined. Concentration of uranium and its decay products in the rock phosphate and products are presented. External gamma exposure and inhalation of radon and progeny are found to be the major routes of exposure to public in phosphogypsum disposal environment. An estimate of the committed effective dose to a representative person gives an average additional dose of 0.6 mSv annually in the study sites.

A PRELIMINARY STUDY OF ISSUES AND PRACTICES CONCERNING PREGNANCY AND IONISING RADIATION

Schreiner-Karoussou, A. — 2009-04-04

A literature review in relation to irradiation of patients and staff during pregnancy was carried out. A number of publications describing procedures to be followed in the case of a pregnant patient who needs to have a radiological examination and in the case of pregnant staff who work in a department where they could be exposed to radiation were reviewed. A review of existing practices in 13 European countries was carried out by sending a questionnaire to representatives in each country. From the review, it was found that the existing practices with respect to irradiation of patients and staff during pregnancy vary enormously. There is no harmonisation on this issue at the European level. From the literature review and the review of practices, a number of ethical issues were identified and exposed and a number of conclusions were drawn.

FEMINIST THEORETICAL PERSPECTIVES ON ETHICS IN RADIOLOGY

Condren, M. — 2009-04-01

The substantive safety of radiological and other medical procedures can be radically reduced by unconscious factors governing scientific thought. In addition, the historical exclusion of women from these disciplines has possibly skewed their development in directions that now need to be addressed. This paper focuses on three such factors: gendered libidos that privilege risk taking over prevention, fragmented forms of knowledge that encourage displaced forms of responsibility and group dynamics that discourage critique of accepted practices and limit the definition of one's group. The substantive safety of the practice and scientific contribution of radiologists might be considerably enhanced were the focus to switch from radiology to diagnosis. Such enlargement might redefine the brief of radiologists towards preventing as well as curing; evaluating some non-invasive and low-tech options, adopting some inclusive paradigms of clinical ecology and enlarging group identities to include those currently excluded through geography or social class from participating in the benefits of science.

LESSONS LEARNT FROM THE ORGAN RETENTION CONTROVERSY

Madden, D. — 2009-04-01

This paper examines the lessons to be learnt from the organ retention controversy in the Republic of Ireland. The paper emphasises the importance of good communication between clinicians and families of deceased persons and a move away from a medical culture based on paternalism to a partnership approach between clinicians and patients based on mutual trust and understanding. A model of authorisation rather than consent is proposed as the way forward for dealing with the difficult and traumatic experience of asking families for permission to carry out a post mortem examination on their deceased child.

JUSTIFICATION AND RADIOLOGY: SOME ETHICAL CONSIDERATIONS

Sia, S. — 2009-03-27

This paper, which seeks to address the issue of justification in radiology, intends firstly to comment on the current discussion of the ethical foundation of radiological practice that focuses on the move from utilitarianism to the rights-centred criterion. Secondly, and this constitutes the bulk of the paper, it aims to offer a philosophical perspective, which is hoped will lead to a consideration of certain specific areas in ethical decision-making in the attempts here to deal with the main issue of justification in radiology.

ETHICAL ISSUES IN RADIOLOGY: A PHILOSOPHICAL PERSPECTIVE

Sia, S. — 2009-03-26

Given that there is much disagreement as to what constitutes ‘philosophy’, even among philosophers, it is a challenge to provide a philosophical perspective. There are, however, at least two areas that most philosophers would regard as coming within the terrain of philosophical thinking: (1) the clarification of issues and (2) providing some sort of a foundation on which further thinking can take place. Thus, by way of contributing a philosophical perspective to the discussion, this paper will clarify some of the more fundamental issues regarding ethical debates in the hope of establishing some kind of theoretical foundation on which to base the discussion of the more specific issues and of widening the scope of the discussion.

ORGANISATION AND DELIVERY OF IMAGING SERVICES: THE CONTRIBUTIONS OF ETHICS AND POLITICAL ECONOMY

Durand-Zaleski, I. — 2009-03-24

The objective of this discussion is to explore how theories from other disciplines can contribute to the debate on organisation and delivery of diagnostic and therapeutic exposures. The first part explores how theories of justice suggest that health services should be provided; the second part explores how stakeholders in the field of public health and health care incorporate their own strategies in the deployment of health technologies and health-care programmes.

RADIATION PROTECTION IN MEDICINE: ETHICAL FRAMEWORK REVISITED

Malone, J. F. — 2009-03-05

The ethical framework within which medicine operates has changed radically over the last two decades. This has been stimulated by events leading to controversy, such as the infant organ retention scandals; concerns about blood products; self regulation of medical practice in the wake of the Harold Shipman Enquiry in the UK; and many other events. It has become obvious following investigations and/or public enquiries that a gap has opened up between what is acceptable to the public on the one hand, and what appears reasonable to, or is at least accepted by, the professionals involved on the other. This paper reviews these issues and some conclusions of a workshop held to consider them. It places the developments in the context of the idea that the approach to problems and communication in a group of people/professionals such as doctors, radiologists, radiation protection specialists, or even the general public may be regarded as a ‘culture’. Current practice of radiation protection in medicine is examined in the light of these considerations.

NON-MEDICAL EXPOSURES--ETHICAL CONCERNS

O'Reilly, G. — 2009-02-25

The scope of the Medical Exposure Directive (MED), 97/43/Euratom (Council Directive 97/43/EURATOM, on the health protection of individuals against the dangers of ionising radiation in relation to medical exposures. OJ L 180 of 09.07.1997), is such that it includes not only those exposures which are part of the normal diagnosis and treatment of patients but also exposures for occupational health surveillance, health-screening programmes, research and medico-legal exposures. This is the first time that radiation protection legislation has tried to deal explicitly with the issue of medico-legal exposures in a European Directive. However, it has done so in the context of a Directive whose primary focus is the protection of patients undergoing diagnostic or therapeutic medical exposures. This may not be an appropriate framework for medico-legal exposures. In considering medico-legal exposures, a significant number of ethical considerations arise. The MED may not adequately take account of these matters and in fact may not be a suitable legal instrument for dealing with them. This paper looks specifically at the issues surrounding medico-legal exposures and considers whether or not the current system provides adequate protection for the individuals exposed.

ETHICAL CONCERNS ARISING FROM SCREENING PROCEDURES SUCH AS MAMMOGRAPHY AND SELF-REFERRAL

Faulkner, K. — 2009-02-21

Shortly after the discovery of X-rays, their harmful effects became apparent. While the harmful effects of ionising radiation were recognised at an early stage, it took some time before a systematic approach to radiation protection evolved. This began with the development of simple rules to reduce the risk of stochastic effects (such as cancer induction) and the occurrence of deterministic injuries (e.g. cataract formation). These rules have evolved into the basic principles of radiation protection, one of which is the concept of justification, which in its simplest form may be taken as doing more benefit than harm. The concept of justification has particular ethical concerns when applied to population screening procedures. These problems are described in this paper with a particular emphasis on the cases of screening and self-referral procedures.

SCREENING/HEALTH CHECKS: CAN THE PATIENT ONLY WIN? WHOLE BODY MAGNETIC RESONANCE IMAGING APPROACHES TO TUMOUR SCREENING

Busch, H. P. — 2009-02-14

One of the greatest challenges for the next decade is the fight against cancer disease. These activities must be based on three premises:

Cancer prevention;

Cancer diagnosis;

Cancer treatment.