La radioprotection des patients en médecine nucléaire : état des lieux en Tunisie

Recent health indicators for Tunisia are encouraging: there is one doctor for every 1000 inhabitants, in contrast to 1471 in 1996; life expectancy at birth is 73.8 years compared with 71.6 years in 1996; and the infant mortality rate is down from 29.7 per thousand in 1996 to 19.5 per thousand. The health infrastructure in Tunisia is partly private and partly public, supported by a well-organized network of university hospitals and clinics and a central pharmaceutical service that imports and distributes drugs. In 1990, there was only one nuclear medicine centre in Tunisia at the Salah Azaiez Institute. In 2013, there are 12 centres, between public and private, with around forty doctors and 50 technicians using 15 gamma cameras, seven single-head, four dual-head and three SPECT/CT. Positron emission tomography (PET) will be acquired in short delay. Training for doctors and technicians in quality control for this new equipment and quality assurance in multimodal molecular imaging will soon become a priority. The protection of patients against radiation remains a major concern for these Departments. The regulatory and institutional framework has been established since 1980. Because of their oldness, they may not be suitable for radiation protection of persons exposed for medical purposes. An assessment of the practice of nuclear medicine can be helpful to standardize used protocols and to optimize the dose delivered to the patients during different nuclear medicine procedures in vivo.     

Sister chromatid exchanges in lymphocytes of nuclear medicine physicians

OBJECTIVE: The aim of this study was to assess whether occupational exposure to chronic, low doses of Iodine 131 (I-131) and Technetium 99m (Tc-99m) may lead to genotoxicity. Medical personnel occupied in nuclear medicine departments are occupationally exposed to low doses of I-131 and Tc-99m. The determination of the frequency of sister chromatid exchanges (SCEs) and of cells with a high frequency of SCEs (HFC) is considered to be a sensitive indicator for detecting genotoxic potential of mutagenic and carcinogenic agents. Therefore, we examined peripheral lymphocytes from nuclear medicine physicians for the presence of both SCE and HFC. METHODS: Sixteen exposed nuclear medicine physicians (non-smokers) were compared to 16 physicians (non-smokers) who had not been exposed to chemical or physical mutagens in their usual working environment at the same hospital. RESULTS: A statistically significant difference was found between SCE frequencies and HFC percentages measured in lymphocytes from the exposed and control groups. CONCLUSIONS: The present observation on the effect of chronic low doses of I-131 and Tc-99m indicates the possibility of genotoxic implications of this type of occupational exposure. Hence, the personnel who work in nuclear medicine departments should carefully apply the radiation protection procedures and should minimize, as low as possible, radiation exposure to avoid possible genotoxic effects.     

Enquête nationale en médecine nucléaire : radiopharmaceutiques et activités utilisés en 2007 dans le secteur public

The Institute for radiation protection and nuclear safety (IRSN) and the National institute for health surveillance (InVS) have been collaborating since 2003 to provide updated data on medical exposure of the French population related to medical diagnosis. In this framework, a survey was carried out by IRSN in 2009 within all the 127 departments of nuclear medicine belonging to public hospitals. The rate of participation was high (72% of the departments). The first objective of this survey was to estimate the activity of these nuclear medicine departments (numbers and types of examination, according to their code in the French common classification for medical care). The second objective was to collect data related to the dose delivered to the patient for each type of examination. This article details this second part of the survey and presents, for the 32 most frequent types of examination, the radionuclide used and its chemical form, the average administered activity per examination and the activity range for the responding departments. When a French dose reference level exists, this survey showed that the average administered activity is in agreement with it, excepted for the ^99mTc thyroid scintigraphy with an administered activity close to twice the dose reference level (DRL). The dispersion of administered activity between the departments for a same type of examination depends on the type of examination, and is comprised between 2 and 10 for a 70 kg patient.     

无陪护老年病人住院期间护理需求的质性研究

目的:了解无陪护老年病人在住院期间的护理需求。方法:采用质性研究中现象学研究的半结构化、面对面、深度访谈方法采访11位内科无陪护老年病人,之后依据Claizzit的现象学资料7步分析法分析、整理资料。结果:无陪护老年病人住院期间的需求涉及病室、护理人员、陪护人员三方面。结论:无陪护老年病人住院期间有着其特殊需求,无陪护的原因主要有经济因素及陪护人员综合素质较低、无统一管理等,所以除了医院在护理工作中针对这类病人给予一些特殊照护外,呼吁政府建立规范的陪护人员培训及管理机构,为广大患者提供正规、专业化的陪护。     

Le point sur les niveaux de référence diagnostiques en médecine nucléaire en 2011

Seven years after the publication of the first diagnostic reference levels (DRL) order, the analysis of the data allows the French Institute for radiation protection and nuclear safety (IRSN) to assess and evaluate the increase of the nuclear medicine departments involvement and of the level administered activities to the patients during the most common examinations performed in France. IRSN analyses show a good agreement between the distribution of transmitted examinations and the frequency of examinations performed in France, taking into account 95% of the number of examinations and 95% of the dose delivered to patients by nuclear medicine. These analyses highlight the necessary consistency between DRL regulation, the French society of nuclear medicine (SFMN) recommendations and national practice. The IRSN recommendations established from data analyses have leaded the authorities to publish a new DRL order in January 2012. This first update of the regulation takes into account actual clinical practice in nuclear medicine and introduces fundamental points as pediatric DRL. In the future, periodical updates will be implemented in order to take into account procedures and devices evolutions.     

Mise en place d’une équipe d’experts en physique médicale au Luxembourg : organisation, résultats qualité et radioprotection en médecine nucléaire (2002–2011)

Implementations of the statutory UE requirements concerning ionizing radiation in the medical domain (96/29/Euratom, 13th May 1996; 97/43/Euratom, 30th June 1997) have changed quality control in medical imaging departments. In Luxembourg, the Ministry of Health and the “Union of Luxembourg Hospitals” have thus created a “Medical Physics Cell” (five Medical Physics experts). It is in charge of implementing a standardized program of Quality Assurance (QA) and radiation protection relative to patients as well as staffs, on a coordinated national basis, in all five in-hospital nuclear medicine departments of the country. The program distributes QA controls between three levels, various periodicities and degrees of expertise. It sensitizes staff and medical doctors by trainings and facilitates ISO accreditation. From 2002 to 2011, in all five in-hospital departments of nuclear medicine of a small country, image quality, radiation protection and reference values of each medical equipment were defined and implemented in a standard way. In 2011, the medical physics cell, the driving force leading to the institutionalization of the discipline within the nuclear medicine departments, is considered as a partner rather than as a control body by the teams in charge of the nuclear medicine departments.     

Structuration des liens entre médecine nucléaire et radiopharmacie

Radiopharmaceuticals are nowadays under the responsibility of the radiopharmacist because of their medicinal product status. Radiopharmacy belongs to the hospital pharmacy department, nevertheless, interactions with nuclear medicine department are important: rooms are included or located near nuclear medicine departments in order to respect radiation protection rules, more over staff, a part of the material and some activities are shared between the two departments. Consequently, it seems essential to formalize links between the radiopharmacy and the nuclear medicine department, setting the goals to avoid conflicts and to ensure patients’ security. Modalities chosen for this formalization will depend on the establishment's organization.     

In vivo exposure of human lymphocytes to technetium-99m in nuclear medicine patients does not induce detectable genetic effects.

Recent reports have demonstrated that exposure of nuclear medicine patients to thallium-201 does not result in a detectable increase in mutation at the hprt locus in human lymphocytes. In an effort to study further the potential genetic effects of medical exposures to low dose radiation, we have examined chromosome aberrations and mutations in peripheral blood lymphocytes from nuclear medicine patients exposed to clinical doses of technetium-99m. Our results show that there is no exposure-related increase in chromosomal damage; furthermore, the data do not confirm earlier reports of exposure-related increases in mutations induced by technetium-99m.     

Direct estimates of low-level radiation risks of lung cancer at two NRC-compliant nuclear installations: why are the new risk estimates 20 to 200 times the old official estimates?

An official report on the health hazards to nuclear submarine workers at the Portsmouth Naval Shipyard (PNS), who were exposed to low-level ionizing radiation, was based on a casual inspection of the data and not on statistical analyses of the dosage-response relationships. When these analyses are done, serious hazards from lung cancer and other causes of death are shown. As a result of the recent studies on nuclear workers, the new risk estimates have been found to be much higher than the official estimates currently used in setting NRC permissible levels. The official BEIR estimates are about one lung cancer death per year per million persons per rem[s]. The PNS data show 189 lung cancer deaths per year per million persons per rem.     

National survey to set diagnostic reference levels in nuclear medicine single photon emission imaging in Croatia

PurposeIn order to introduce the concept of diagnostic reference levels (DRLs) in the national nuclear medicine practice a survey was proposed and completed through all nuclear medicine departments in Croatia. An additional aim was to increase the awareness of importance and full implementation of a comprehensive quality program that includes devices used in the nuclear medicine chain.MethodsData were collected for more than 30 nuclear medicine single photon emission procedures. National DRLs (NDRLs) as administered activity and also as administered activity per unit mass were calculated in accordance to International Commission on Radiological Protection (ICRP) recommendations. Additionally, effective doses were estimated using conversion factors published by the ICRP.ResultsNDRLs for nuclear medicine single photon emission procedures were proposed. For procedures performed in only one department typical values were presented as reference. Effective doses related to applied radiopharmaceuticals were calculated to estimate radiation risk related to respective nuclear medicine procedure in more detail.ConclusionThis work presents results of the first national survey on DRLs of nuclear medicine single photon emission procedures and proposes reliable NDRLs that represent an actual status of nuclear medicine practice in Croatia. Results have motivated departments to introduce and set their own typical values to be used, as one of the tools, for further optimization process. One of the drawbacks of the DRL concept in nuclear medicine is the lack of the image quality parameters involved. For this reason, a quantity that considers both radiation protection and image quality should be introduced.     

Suicide and public health

Suicide as a public health problem is generally underestimated. Deaths from suicide annually outnumber those from cancer of the respiratory system or of other common sites; more than twice as many die by suicide as from most communicable diseases combined. Most suicides are motivated by concern over ill health or domestic difficulties.A program tried in Yolo County to follow up persons who have attempted suicide indicates that a more systematic and widespread effort in this direction might be of value to the public health. It is recommended that attempts at suicide be considered a reportable disease for a one-year period and that a statewide program for following the patients be put into effect to provide rehabilitation as well as symptomatic treatment. Efforts by local health departments and private physicians are also worth while in reducing attempts at suicide.     

SUICIDE AND PUBLIC HEALTH

Suicide as a public health problem is generally underestimated. Deaths from suicide annually outnumber those from cancer of the respiratory system or of other common sites; more than twice as many die by suicide as from most communicable diseases combined. Most suicides are motivated by concern over ill health or domestic difficulties.A program tried in Yolo County to follow up persons who have attempted suicide indicates that a more systematic and widespread effort in this direction might be of value to the public health.It is recommended that attempts at suicide be considered a reportable disease for a one-year period and that a statewide program for following the patients be put into effect to provide rehabilitation as well as symptomatic treatment. Efforts by local health departments and private physicians are also worth while in reducing attempts at suicide.     

Karyopathological traits of thyrocytes and exposure to radioiodines in Belarusian children and adolescents following the accident at the Chernobyl nuclear power plant

The Belarus-American (BelAm) thyroid study cohort consists of persons who were 0-18 years of age at the time of exposure to radioactive iodine fallout from the 1986 Chernobyl nuclear power plant accident and who have undergone serial thyroid screenings with referral for fine-needle aspiration biopsy (FNAB) using standardized criteria. We investigated thyrocyte nuclear abnormalities in cytological samples from FNABs in 75 BelAm subjects with single and multiple thyroid nodules and 47 nodular goiter patients from Leningrad, Russia, unexposed to Chernobyl fallout. Nuclear abnormalities examined included internuclear chromosome bridges and derivative nuclei with broken bridges (i.e., "tailed" nuclei), which are formed from dicentric and ring chromosomes and thus may be cellular markers of radiation exposure. Among subjects with single-nodular goiter, thyrocytes with bridges were present in 86.8% of the exposed BelAm cohort compared with 27.0% of unexposed controls. The average frequency of thyrocytes with bridges and with tailed nuclei was also significantly higher in the BelAm subjects than in controls. Among subjects with multinodular goiters, thyrocytes with bridges were present in 75.7% of exposed BelAm patients compared with 16.7% of unexposed controls; thyrocytes with tailed nuclei were observed in all of the BelAm subjects but in only 40% of controls, and the mean frequencies of bridges and tailed nuclei were significantly higher in the exposed group. Unusually, long bridges were detected in 29% of BelAm patients with single-nodular goiters and 35% of those with multinodular goiters, while no such abnormalities were observed among patients from the Leningrad region. In the exposed subjects from BelAm, we also found positive correlations between their estimated dose of Iodine-131 from Chernobyl fallout and the frequency of tailed nuclei (p = 0.008) and bridges (p = 0.09). Further study is needed to confirm that these phenomena represent consequences of radiation exposure in the human organism.     

Wrist dosimeter in nuclear medicine – An alternative for the ring dosimeter?

PurposeIndividual dosimetry is undoubtedly one of the best methods of assessing the exposure of personnel to ionizing radiation, however in case of nuclear medicine, the method applied to measure the dose does not always present a picture of the worker’s actual exposure. The highly non-homogeneous dose distribution on the hand means that the ring dosimeter, routinely used to measure the Hp(0.07), provides only approximate dose values received by fingertips, the body part most exposed to ionizing radiation. This paper is an attempt to answer the question whether the wrist dosimeter used as a replacement for the ring dosimeter is able to provide information on doses for the most exposed fragments of the hand of an employee during handling procedures with the use of radiopharmaceuticals.MaterialsThroughout measurements performed in five nuclear medicine facilities, high-sensitivity thermoluminescent detectors were used.ResultsCorrection coefficients have been determined, which constitute an amendment to be made to move from the dose recorded by the wrist dosimeter to the doses received by the most exposed hand fragments. The fingertips received on average 25 times higher doses, compared to the values recorded by the wrist dosimeter.ConclusionsA wrist dosimeter can be used to measure the Hp(0.07) in nuclear medicine, including as a gauge of the most exposed parts of the hand – the fingertips. However, the applicability of correction coefficients makes it necessary to ensure a stable position of the wrist dosimeter during routine procedures.     

Répartiteur de dose des médicaments radiopharmaceutiques : contrôle qualité sur deux sites hospitaliers et comparaison avec la législation en vigueur en France

An increasing number of nuclear medicine departments are equipped with automated measurement systems for the preparation of radiopharmaceuticals, with the main aim of minimising technician's irradiation. However, the automatic measurement of the patient activity differs from the manual measurement in material and method. In this context, the objective of the present study was to test the performances of one of these systems, the Unidose by TRASIS^®, in two newly equipped hospitals. The particularity of these systems is they are made up of two dose calibrators: the entrance calibrator (well chamber) and the exit calibrator (probe). Controls were performed on both of these dose calibrators. The results obtained, as well as the methodology employed, were then compared with the regulatory requirements in France. The results found are coherent between the two sites and have highlighted several non-conformities compared to the current regulations, part of which concerning the carpule dose calibrator, which is actually a probe. These results raise the question of a suitable regulation for the new automated measurement systems in nuclear medicine.     

Results of artificial immunization of Rh-negative persons for the production of anti-D(RhO)-antibodies

By means of a recording sheet the data about 62 artificially immunised male persons are evaluated retrospectively. 51 of them (82.3%) were anti-D-antibodies, with 41 of them having a high titer sufficient for gaining plasma. 2/3 of all test persons formed an accompanying antibody anti-C. In order to avoid this, persons of Rh-formula Cde may be included into artificial immunisation. An anti-E as an accompanying antibody was found in 2/3 of those test persons who had received injections of cDE blood. The blood of this Rh-formula will yield better immunising results than cDe blood. It was only in three immunised persons (4.8%) that side effects with a light or medium course of seriousness could be observed. It is necessary to develop immunobiological investigation methods to recognize those persons prior to the arteficial immunisation, who are suitable or unsuitable for anti-D-antibody formation.     

Pénurie de technétium99m : des pistes pratiques pour gérer les périodes de crise dans les services de médecine nucléaire

Technetium^99m (^99mTc) shortage crisis regularly affect nuclear medicine activity and oblige the community to find solutions in order to perform most of the prescribed exams and avoid systematic substitutions by other non-nuclear medicine techniques. Firstly, some practical solutions can be set up in radiopharmacy departments such as using more than two generators together, realizing fractionated elutions, preparing radiopharmaceuticals with elutions providing from different generators… Then, it could be interesting to have a reflexion in nuclear medicine departments to convene patients the days when ^99mTc supply is sufficient, to pool some exams or to make substitutions with more available isotopes.     

Anti-Rhinosporidial Antibody Levels in Patients with Rhinosporidiosis and in Asymptomatic Persons,in Sri Lanka

The only report hitherto, from India in 1982, on anti-rhinosporidial antibody levels in patients with rhinosporidiosis recorded that antibody was not detected in Indian patients. The present report describes the use of the dot-ELISA assay of serum anti-rhinosporidial IgG, IgM and IgA and salivary sIgA in patients with diverse clinical presentations, in rural asymptomatic persons who had bathed in ground waters that probably harboured the causative pathogen, Rhinosporidium seeberi, and in laboratory persons who were exposed to R. seeberi. Ultrasonic extracts of purified endospores and sporangia of R. seeberi were used as antigen. The geometric mean (reciprocal) titres of serum antibody detected in patients were IgM 142.1, IgG 178.5, IgA 84.6, with ranges of 0-640, 30-960 and 0-160 respectively, salivary sIgA titres ranged from 0 to 18 with a mean of 4.6. The levels of antibody had no correlation with the site, the number of sporangia, duration and recurrence of the disease. Asymptomatic persons from the same endemic area as patients showed mean titres of IgM 89.6, IgG 69.1, IgA 95.5, with salivary sIgA titres of 3.1. Asymptomatic personnel who had been working in a laboratory where rhiniosporidial work was being done, showed mean titres of 169.6 IgM, 62.8 IgG, and 6.5 salivary sIgA. These results indicate that an anti-rhinosporidial antibody response occurs in rhinosporidial patients, as well as in asymptomatic persons who were exposed to R. seeberi in the environment. Anti-R. seeberi antibody does not appear to be protective in rhinosporidiosis since appreciable titres were present in patients with recurrent, single, multiple or disseminated lesions of long duration.