International project on individual monitoring and radiation exposure levels in interventional cardiology.

Within the Information System on Occupational Exposure in Medicine, Industry and Research (ISEMIR), a new International Atomic Energy Agency initiative, a Working Group on interventional cardiology, aims to assess staff radiation protection (RP) levels and to propose an international database of occupational exposures. A survey of regulatory bodies (RBs) has provided information at the country level on RP practice in interventional cardiology (IC). Concerning requirements for wearing personal dosemeters, only 57 % of the RB specifies the number and position of dosemeters for staff monitoring. Less than 40 % of the RBs could provide occupational doses. Reported annual median effective dose values (often <0.5 mSv) were lower than expected considering validated data from facility-specific studies, indicating that compliance with continuous individual monitoring is often not achieved in IC. A true assessment of annual personnel doses in IC will never be realised unless a knowledge of monitoring compliance is incorporated into the analysis.

[Can we optimize radioprotection for medical workers?]. / Peut-on optimiser la radioprotection des travailleurs dans le domaine médical?

Implementation of the principle of optimization (ALARA), an essential radiation protection regulations, remains very limited in the medical field, even though 80% of workers whose exposure exceeds 50 mSv are to be found in this domain. The doses measured by legal dosimetry sometimes underestimate the real exposure of workers. It is therefore necessary to optimize the protection of occupational exposure in the medical field. This paper reviews the steps of the optimization procedure with emphasis on specificity of its application in this domain. Operational dosimetry as well as information on the residual risk due to low exposures and a better estimation on the risk/benefit factor for the patient are needed for satisfactory implementation.

Doses to patients from dental radiology in France.

In France, a national study was undertaken to estimate both dental radiology practices (equipment and activity) and the associated population collective dose. This study was done in two steps: A nationwide survey was conducted on the practitioner categories involved in dental radiology, and dosimetric measurements were performed on patients and on an anthropomorphic phantom by using conventional dental x-ray machines and pantomographic units. A total of 27.5 x 10(6) films were estimated to have been performed in 1984; 6% of them were pantomographic and 94% were conventional. Most of the organ doses measured for one intra-oral film were lower than 1 mGy (100 mrad); pantomogram dose values were generally higher than intra-oral ones. The collective effective dose equivalent figure was 2,000 person-Sv (2 x 10(5) person rem) leading to a per head dose equivalent of 0.037 mSv (3.7 mrem). The study allowed authors to identify ways to reduce the patient dose in France (e.g., implementing the use of long cone devices and controlling darkroom practices).

Contrasted diffusion and the use of CT scanner equipment in France.

During the last 4 years, there has been a rapid catching-up in the distribution level of CT-scanners in France. In a survey of CT-scanner utilization, data from all machines operating in the PACA Region in 1986, showed that the mean activity was 6,080 examinations per machine. The co-existence of both private and public medicine led to different use of materiel (5,500 to 5,800 exams per machine in the public versus 8,600 in the private sector and a higher productivity in the profit-making establishments. This difference was not explained by procedural variations in carrying out the technique, which appeared to be similar and standardized everywhere, but probably reflected patient selection (80% of ambulatory patients in the private sector, 25 to 50% in PTH).

[The financing of medico-technical activities. The example of a scanner in France (1986)]. / Le financement des actes médico-techniques. L'exemple du scanner en France (1986).

To analyse the french methods for financing technical-medical activities as CT scanners, and to assess if they can face, or not, the management constraints of such activities a financial simulation has been executed. First, current expenditures are totalized (including depreciations and financial charges) with variations according to the number of examinations per year. Costs are classified especially according to fixed and variable charges: the weight of fixed charges, especially equipment charges, is the most significant. It's very high in yearly expenditures. Most, that involves a very fast decreasing cost with increasing number of procedures. Second, consequences of such accounts are analyzed: on private CT scanners, Payed with a charge per examination whatever would be the factor's cost; on public CT scanners, payed with an annual allowance; in this case charges equal receipts whatever would be the cost for a procedure. Third, a break point is defined; either the annual activity is higher: there would be an excedent; either it is lower: there would be a deficit. Then, those results are reported to CT-scanners activity's data in France (1986). After all, we discuss about financing systems themselves, and suggest a few hypothesis to explain those desadjustments between charges and their financing way.

Doses to patients from diagnostic radiology in France.

Reported here are results of a 1982 national survey in France to establish the collective effective dose equivalent associated with the main types of radiological examinations practiced annually in this country (except nuclear medicine, C.T. scans, dental radiology and mass chest screening). This report describes the methodology followed in achieving dose measurements either on an anthropomorphic phantom or directly on the patient, and it highlights the importance of the radiological procedures (number of x-ray films, fluoroscopy screening time, etc.) on the patient organ doses. The estimated collective effective dose equivalent associated with these radiological practices is 86,000 person-Sv, i.e., an individual effective dose equivalent of 1.58 mSv y-1; the genetically significant dose figure is 0.29 mSv and the collective red bone marrow dose due to 45 million x-ray exams practiced in France (1982) is 40,300 person-Sv, i.e. 0.74 mSv per inhabitant.

[The practice of x-ray computed tomography during a period of rapid growth. A survey on the Provence-Alpes-Côte d'Azur region in 1986]. / La pratique de la tomodensitométrie en période de croissance rapide du parc. Enquête dans la région Provence-Alpes-Côte d'Azur en 1986.

From May to September 1986, a sample of 748 CT-scanner examinations, representative of the total annual activity, has been collected in Provence-Alpes-Côte d'Azur Region. The regional activity of CT-scanner has been estimated to 91,200 examinations in 1986 (total France: 628,500 in 1985) or 22.7 procedures per 1,000 inhabitants (total France: 11,4 in 1985). CT-scanner is now a routine diagnostic imaging device with an annualized average of 6,080 procedures per machine (5,770 in public sector and 8,415 in the for-profit private one). The mean effective utilization time for a machine in one year was 2,700 hours in a regional, public, teaching hospital (PTH) and 3,100 in private, for-profit establishment (PPE). The number of procedures per machine-use hour was 2,4 in PTH and 2.8 PPE. No procedural difference has been observed between the two sectors in carrying out the technique. CT-Scanner diffusion in the private for profit sector has meant: - an increase in the demand from general medical practionners (more than 1/4 examinations); - a larger range of indications concerning less serious health conditions.

[Evaluation of the policies for detection of pulmonary tuberculosis in France]. / Contribution à l'évaluation de la politique de dépistage de la tuberculose pulmonaire en France.

A survey of 984 cases of pulmonary tuberculosis was carried out to assist French public health authorities in determining policies for pulmonary tuberculosis detection. The adjusted sample was representative of the totality of pulmonary tuberculosis cases reported. The survey made it possible to define the economic and socio-demographic characteristics (age, nationality, lack of social security coverage, living conditions) which, when combined, represent high-risk attributes with regard to pulmonary tuberculosis. Nonetheless, over half the subjects studied presented no risk factors. Systematic X-ray screening of an undifferentiated population permits detection of about 23% of reported cases; among them, 26 or 50% (depending on the definition of contagiousness chosen) were contagious. In 1982, 9 million systematic X-ray screenings were performed and about 13,100 cases of pulmonary tuberculosis reported. When extrapolated to these 1982 figures, our survey conclusions point to an effectiveness rate for systematic X-ray screening of 33.7 per 100,000 for the overall tuberculosis population, and between 8.9 and 17.4 per 100,000 for contagious cases. On the other hand, high-risk groups (female immigrants, the aged, etc.) do not seem to be particularly well covered by systematic X-ray screening. Thus, maintaining such a program no longer appears justified either in terms of the overall tuberculosis population or that of high-risk subgroups.

[Collective irradiation caused by radio-diagnostic procedures in France in 1982. Results (2)]. / L'irradiation collective due aux pratiques de radiodiagnostic en France en 1982. Les résultats (2e partie).

This paper gives the most important results of the collective dose received by patients who undergoing diagnostic radiology examinations in France in 1982. It details, per each X-ray examination type, the collective organ dose associated with, and highlights the importance of the radiological procedures (number of X-ray films, fluoroscopy screening time) on the received patient doses. If one takes into account organs for which dosimetric measurements have been carried out, the collective effective dose equivalent per 10(6) inhabitants is 442 man-Sievert; the genetically significant dose reaches 0.295 mSv and finally the collective red bone marrow dose due to 45 million X-ray exams practiced in France (1982) is 40,300 man-Sievert i.e. 0.742 mSv. per inhabitant.

[Collective radiation dosage due to radiodiagnostic practice in France in 1982. Methodology. 1]. / L'irradiation collective due aux pratiques de radiodiagnostic en France en 1982. Méthodologie (1re partie).

This paper recalls the main concepts of dosimetry which are useful when assessing the collective dose to the patient from medical X-ray examinations. It describes the general protocol which has been followed in measuring dose associated to each x-ray exam (anthropomorphic phantom, in vivo measurement) and gives some results about the variations of parameters such as the mAs, the kVp and the fluoroscopy screening time. As far as the gonadal dose and the effective dose equivalent are concerned a first evaluation is given per type of examination carried out in France in 1982.

[National survey on radiodiagnosis. Comparative analysis of the activity of different sectors (3)]. / Enquête nationale sur le radiodiagnostic. Analyse comparative de l'activité des différents secteurs (3 partie).

The survey has estimated the global annual production of radiological procedures in France (1982) at 45,4 millions. The large public hospitals (including University hospitals) produce up to 42% of the total; the mean number of annual procedures by X-Ray unit being 4 000, in this sector. The private sector (including clinics and offices) has a production ratio between 2 350 and 2 800 annual procedures by X-Ray Unit; some type of examinations are over represented as compared with the public sector for example lumbar and dorsal spine and digestive. Specialized procedures such as vascular and neuro-radiological represent a quasi monopoly of the public sector. In term of economic behavior, some differences appear between the public and private sectors in the way to account for the procedures to the Social Security System. These are partly due to differences in the complexity of the procedures (for example in the case of abdomen, stomach and upper G.I., the latter being more often performed in hospitals) and to different medical practices (number of films; utilisation of divided films, etc.). The share of procedures executed under the responsibility of a radiologist yields 88% of the total.

[National survey on radiodiagnosis. Personnel and equipment (2)]. / Enquête nationale sur le radiodiagnostic. Les moyens en personnel et en matériel (2e partie).

The total projected number of units (including tables and potters) has been estimated at 16 325 in 1982, at the exclusion of radiological dental systems and unit exclusively devoted to mass X-Ray examinations. Almost half of this total equipment is located in public hospitals (including University hospitals), where the departments have a mean size which is markedly greater than the private sector (clinics and physicians' offices). One of the main feature of the French equipment is the high rate of remote controlled machines (almost 40%). The total labor forces involved directly in this activity has been estimated to 46 000; of which 14 580 are physicians (radiologists or not) and 18 680 are radiographers. The mean productivity, computed in annual mean number of examinations per person (medical and para-medical) is estimated at 1 000. These results are examined and compared throughout the different sectors (public and private; hospital, clinic and ambulatory care).

[National survey of radiodiagnosis. Methodological aspects (1)]. / Enquête nationale sur le radiodiagnostic. Aspects méthodologiques (1re partie).

A national sample of 386 radiological departments and offices representative of a total set of approximately 5 000 have been involved in a statistical survey during the years 81-82. This survey was first directed to the analysis of the production factors related to radiology (number and characteristics of facilities and equipment; medical and paramedical personnel, ...). The radiological activity has then been observed during one week (in June 82) through systematic questionnaires. The information collected on about 13 000 X-Ray examinations consists in characteristics of the population examined, the aims and results of examination, a technical description of procedures (number and size of films; projection; physical parameters, ...). This survey has excluded X-Ray routine examinations (occupational and others); dental examinations, isolated fluoroscopy and ultrasound practiced by physicians.