Patient radiation doses in the most common interventional cardiology procedures in Croatia: first results.

Apart from its benefits, the interventional cardiology (IC) is known to generate high radiation doses to patients and medical staff involved. The European Union Medical Exposures Directive 97/43/Euroatom strongly recommend patient dosimetry in interventional radiology, including IC. IC patient radiation doses in four representative IC rooms in Croatia were investigated. Setting reference levels for these procedures have difficulties due to the large difference in procedure complexity. Nevertheless, it is important that some guideline values are available as a benchmark to guide the operators during these potentially high-dose procedures. Local and national diagnostic reference levels (DRLs) were proposed as a guidance. A total of 138 diagnostic (coronary angiography, CA) and 151 therapeutic (PTCA, stenting) procedures were included. Patient irradiation was measured in terms of kerma-area product (KAP), fluoroscopy time (FT) and number of cine-frames (F). KAP was recorded using calibrated KAP-meters. DRLs of KAP, FT and F were calculated as third quartile values rounded up to the integer. Skin doses were assessed on a selected sample of high skin dose procedures, using radiochromic films, and peak skin doses (PSD) were presented. A relative large range of doses in IC was detected. National DRLs were proposed as follows: 32 Gy cm(2), 6.6 min and 610 frames for CA and 72 Gy cm(2), 19 min and 1270 frames for PTCA. PSD <1 Gy were measured in 72 % and PSD >2 Gy in 8 % of selected patients. Measuring the patient doses in radiological procedures is required by law, but rarely implemented in Croatia. The doses recorded in the study are acceptable when compared with the literature, but optimisation is possible. The preliminary DRL values proposed may be used as a guideline for local departments, and should be a basis for radiation reduction measures and quality assurance programmes in IC in Croatia.

Possible discrepancies between dicentric chromosome frequencies and recorded ionizing radiation doses: in vivo study.

BACKGROUND: The available data on the effects of radiation on humans are limited to the reports of accidental exposure or studies of patients under diagnostic and therapeutic treatment; few reports refer to a occupationally exposed population groups. METHODS: The research was conducted on 66 subjects employed in the Department of Nuclear Medicine and 41 nonemployed controls. For each of them chromosomal analysis and gamma-spectrometer analysis of 24-hour urine were carried out. Exposure doses were measured using film-badge dosimetry. RESULTS: The comparison of dosimetric data obtained by film-badge measurements and the frequency of dicentric chromosomes in each subject revealed no correlation between the two observed parameters. CONCLUSIONS: In view of the above results, the subjects should be studied within job/task groups as they are far more likely to receive comparable doses.

A nine-year follow up study of a population occupationally exposed to vinyl chloride monomer.

The presence of structural chromosome aberrations and sister chromatid exchange frequencies (SCE) were studied in lymphocytes from 28 male subjects occupationally exposed to vinyl chloride monomer for a period of 9 years. A significant increase in chromosomal damages and elevated SCE frequencies was detected during the third and fourth year of the follow-up study. During the last 2 years, all examined parameters are approaching control values. This is a result of decreasing vinyl chloride monomer concentrations in the working environment without interrupting the working process.

Relationship between locations of chromosome breaks induced by vinyl chloride monomer and lymphocytosis.

The distribution of vinyl chloride monomer (VCM)-induced chromosome breaks was studied in cultured lymphocytes of subjects occupationally exposed to this gas. In the examined subjects, the mean group value of chromosome aberrations is 6.5% and for sister chromatid exchange (SCE) frequencies, the mean value per cell is 7.9. These values are significantly higher than in the control population. Occupational exposure to VCM caused lymphocytosis together with disturbances of mitogenic activity in lymphocytes stimulated by phytohaemagglutinin. The results of G-banding showed that sites of chromosome breakpoints caused by VCM can be related to the lymphatic tissue disorders.

The sensitivity of the micronucleus assay for the detection of occupational exposure to vinyl chloride monomer.

The micronucleus assay was performed in the peripheral lymphocytes of 32 subjects occupationally exposed to vinyl chloride monomer (VCM) divided into two groups according to years of employment. Blood samples were taken in the period from 24 h to 90 days following a transitory exposure to elevated VCM concentrations of 300 ppm due to the technological process. In subjects with a longer period of employment micronucleus frequencies decreased in proportion to the length of the interval after the last exposure to VCM. The results confirm that the micronucleus assay can serve as a suitable indicator of the time elapsed after last exposure to elevated concentrations of environmental mutagen. It can be assumed that duration of employment may contribute to the occurrence of the cumulative effect produced by exposure to elevated VCM concentrations.

The value of cytogenetic monitoring versus film dosimetry in the hot zone of a nuclear power plant.

Cytogenetic analysis was carried out in 41 workers prior to and following regular maintenance work in a nuclear power plant. Although film dosimetry did not show the maximal annual permitted dose in any of the examined subjects, cytogenetic analysis carried out following the work detected dicentric chromosomes in peripheral blood lymphocytes of 20 workers. According to our findings smoking habits and previous exposure to ionizing radiation had no effect on the increased number of chromosomal aberrations.

Environmental effects on chromosomes in oncology and radiology department personnel.

Long-term, low levels of antineoplastic drugs and ionizing radiation in the work environment may have genotoxic effects on chromosomes in personnel. The effects of ionizing radiation is acknowledged in occupational medicine and therefore various measures have been undertaken to prevent such effects. However, there are no protective measures for workers exposed to antineoplastic drugs. In this study metaphase chromosome preparations were analyzed in 126 nurses and radiology technicians. They were divided into three equal groups. The first group consisted of shift nurses in an oncology department handling antineoplastic drugs. The second group consisted of radiology technicians in a radiology department and the third group acted as controls. Structural chromosomal aberrations were increased among those nurses exposed to antineoplastic drugs in comparison with technicians (P less than 0.05) and controls (P less than 0.01), respectively.

Biological monitoring of three 60Co radiation incident victims.

Radiation-induced structural chromosomal aberrations were the only adverse effects found in three workers overexposed to 60Co gamma-radiation. Chromosomal analyses were performed on the 5th and 75th days after exposure. Hematologic follow-up was carried out on the 5th, 12th, 16th, and 75th days after exposure. Hematologic findings did not differ over time in any of the three exposed workers. In two workers, we found dicentric chromosomes, which are conventional indicators for exposure to ionizing radiation.