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The purpose of this study was to assess the prevalence of lung cancer in a high-risk asbestos-exposed cohort using low-dose MDCT. Of a population of 5,389 former power-plant workers, 316 were characterized as individuals at highest risk for lung cancer according to a lung-cancer risk model including age, asbestos exposure and smoking habits. Of these 316, 187 (mean age: 66.6 years) individuals were included in a prospective trial. Mean asbestos exposure time was 29.65 years and 89% were smokers. Screening was performed on a 16-slice MDCT (Siemens) with low-dose technique (10/20 mAs(eff.); 1 mm/0.5 mm increment). In addition to soft copy PACS reading analysis on a workstation with a dedicated lung analysis software (LungCARE; Siemens) was performed. One strongly suspicious mass and eight cases of histologically proven lung cancer were found plus 491 additional pulmonary nodules (average volume: 40.72 ml, average diameter 4.62 mm). Asbestos-related changes (pleural plaques, fibrosis) were visible in 80 individuals. Lung cancer screening in this high-risk cohort showed a prevalence of lung cancer of 4.28% (8/187) at baseline screening with an additional large number of indeterminate pulmonary nodules. Low-dose MDCT proved to be feasible in this highly selected population. [ABSTRACT FROM AUTHOR]

Asbestos fibers can lead to pulmonary fibrosis, thickening of the pleura and malignancies. These pathologic changes are possible rather than determinate and depend on the type of asbestos fiber, length of exposure to fibers and individual factors. In Germany asbestos fibers were widely used until 1993. Worldwide, there is currently no general ban on the use of asbestos. The leading cause of asbestos-related diseases is occupational exposure. Due to a long latency period the appearance of such diseases may be delayed for more than 40 years so that the final number of cases has not yet been reached. Occupationally-derived asbestos-related diseases of the thorax are asbestosis, asbestos-related benign pleurisy and malignant pleural mesothelioma. Bronchial carcinoma can also be caused by asbestos exposure. For proof of occupational exposure, radiologists are required to report the presence of characteristic findings. The detection, in particular by chest X-ray and high resolution computed tomography (HRCT), requires high quality images and standardized evaluation. The standardized ILO classification and the semi-quantitative HRCT coding are medical findings on which statutory registration criteria are based.

Without imaging procedures a variety of chest diseases cannot be diagnosed sufficiently. Examples are acute and chronic pneumonia, toxic effects on the bronchial and alveolar system, immunologic and malignant changes and cardiovascular disease involving the lung. Especially important are the types of disease that attack large sections of a population, because a path of infection may be hidden or because of short- or long-term exposure to relevant concentrations of toxic or allergic agents--not necessarily recognized as such--at work, in the general environment or associated with certain types of behaviour or illness. All this may have effects on biostatistical and socioeconomic data. Considering available epidemiologic data on morbidity and mortality, then pulmonary tuberculosis, unspecific pneumonias, drug-induced and AIDS-associated lung disease, pneumoconioses (silicosis and asbestosis) and primary and secondary chest malignancies have to be included in this category. Conventional chest radiography with high-kV technique and modern film-screen combinations continues to be the imaging modality for initial evaluation of chest disease worldwide. Low radiation exposure, low cost and overall availability are major advantages. Conventional tomography, however, has nowadays been largely replaced by CT, though a few special indications remain. High-resolution CT (HRCT) and the spiral technique bring additional benefits. Periodic radiographic mass screening of populations with certain disease prevalence still seems feasible, taking risk assessment, cost effectiveness and radiation exposure into account.(ABSTRACT TRUNCATED AT 250 WORDS)