Screening for lung cancer: U.S. Preventive Services Task Force recommendation statement.

DESCRIPTION: Update of the 2004 U.S. Preventive Services Task Force (USPSTF) recommendation on screening for lung cancer. METHODS: The USPSTF reviewed the evidence on the efficacy of low-dose computed tomography, chest radiography, and sputum cytologic evaluation for lung cancer screening in asymptomatic persons who are at average or high risk for lung cancer (current or former smokers) and the benefits and harms of these screening tests and of surgical resection of early-stage non-small cell lung cancer. The USPSTF also commissioned modeling studies to provide information about the optimum age at which to begin and end screening, the optimum screening interval, and the relative benefits and harms of different screening strategies. POPULATION: This recommendation applies to asymptomatic adults aged 55 to 80 years who have a 30 pack-year smoking history and currently smoke or have quit within the past 15 years. RECOMMENDATION: The USPSTF recommends annual screening for lung cancer with low-dose computed tomography in adults aged 55 to 80 years who have a 30 pack-year smoking history and currently smoke or have quit within the past 15 years. Screening should be discontinued once a person has not smoked for 15 years or develops a health problem that substantially limits life expectancy or the ability or willingness to have curative lung surgery. (B recommendation).

UTILITY OF ROUTINE CHEST RADIOGRAPHS IN KENYA.

BACKGROUND: Many otherwise healthy Kenyans are required to obtain chest radiographs as part of routine medical examination to exclude pulmonary TB, a condition of significant public health concern. Many of these people are required to have these radiographs taken yearly as part of routine check-up. No local data is available to support this practice. Though a quick procedure to perform and readily available throughout the country, chest radiograph exposes the individual to a dose of ionising radiation. Ionising radiation is associated with increased risk of malignancy. The cost is also substantial. OBJECTIVE: To determine the prevalence of radiological findings consistent with PTB among routine medical examination chest radiographs. DESIGN: A cross-sectional descriptive study. SETTINGS: Department of Radiology Kenyatta National Hospital, Department of Imaging and Radiation Medicine, University of Nairobi, Plaza Imaging Solutions, a private radiology practice in Nairobi and Department of Radiology, the Nairobi Hospital. SUBJECTS: Four hundred and two chest radiographs of patients presenting for routine medical examinations were analysed. RESULTS: Sixty three radiographs had abnormal but clinically insignificant findings (16%). Only one radiograph (0.25%) had radiological features of PTB. The rest were reported as normal (84%). CONCLUSION: In this study, the diagnostic yield for the intended purpose (to include/ exclude PTB) was extremely low (0.25%). It is recommended that routine chest radiographs as screening tools for active pulmonary tuberculosis be reconsidered due to poor diagnostic yield. The authors propose a bigger nation wide study before a policy decision can be proposed.

Screening for lung cancer: Who should be screened?

Lung cancer is the most common cause of death from cancer in the United States. Previous studies of screening with chest radiographs and sputum cytology have not been shown to decrease lung cancer mortality. For the first time, a randomized screening trial with low-dose computed tomography scans has demonstrated a 20% lung cancer mortality reduction compared with screenings with a chest x-ray. Investigation is underway on many breath, sputum, and blood biomarkers to determine markers of high risk. The hope is that some (or one) of them will add to the early detection of lung cancer observed with low-dose computed tomography.

[Results of the thoracic radiography profile of 247 candidates at the recruiting office of a land-transport society in Abidjan, Cote d'Ivoire]. / Resultats du bilan radiographique thoracique de 247 candidats a l'embauche dans une Societe de Transport Terrestre a Abidjan (Cote D'Ivoire).

The purpose of this prospective study done from May to July 2007 was to show the interest of systematic chest X-Ray of future bus conductors. The main abnormalities were big heart, parenchymal lesion and pleural effusion.

Medical radiation exposure and breast cancer risk: findings from the Breast Cancer Family Registry.

Moderate to high-dose radiotherapy is known to increase the risk of breast cancer. Uncertainties remain about the effects of low-dose chest X-rays, particularly in individuals at increased genetic risk. We analyzed case-control data from the Breast Cancer Family Registry. Self-reported data on therapeutic and diagnostic radiation exposures to the chest were available for 2,254 breast cancer cases and 3,431 controls (1,556 unaffected sisters and 1,875 unrelated population controls). We used unconditional logistic regression analyses to estimate odds ratios (OR) and 95% confidence intervals (CI) associated with radiation exposure, after adjusting for age, study center, country of birth, and education. Increased risks for breast cancer were found for women who had radiotherapy for a previous cancer (OR=3.55, CI=1.47-8.54) and diagnostic chest X-rays for tuberculosis (OR=2.49, CI=1.82-3.40) or pneumonia (OR=2.19, CI=1.38-3.47). Risks were highest for women with a large number of exposures at a young age or exposed in earlier calendar years. There was no evidence of increased risk associated with other diagnostic chest X-rays (not including tuberculosis or pneumonia), both in women with and without indicators of increased genetic risk (i.e., diagnosed at age <40 years or family history of breast cancer). Given the widespread and increasing use of medical diagnostic radiation, continued surveillance of breast cancer risk is warranted, particularly in women at specific genetic risk, such as those carrying mutations in BRCA1 or BRCA2.

The futility of universal pre-employment chest radiographs.

In a developmental center, a preemployment chest x-ray was required for all job applicants. We scrutinized the pros and cons of this practice through a review of the medical literature and our experience, and discussion with our colleagues. We concluded that such chest x-ray caused unwarranted radiation exposure, did not produce compliance with the tuberculosis laws, gave a false sense of security regarding workers' compensation risk management, was contrary to established occupational medicine practice guidelines, and was unnecessary and wasteful. We discontinued such chest x-rays. The purpose of the pre-employment examination should remain narrowly job related. Even long-established procedures require periodic utilization review.

[Initial cost-benefit analysis of chest fluoroscopy in synthetic clue investigation on tuberculosis].

Body surface exposure to X-ray radiation was measured in those with synthetic clue investigation on tuberculosis. The results showed body surface exposure in them appeared a logarithmic normal distribution with a geometric mean of 0.19 mC/kg and was higher than that with fluoroscopy in routine check-ups. The late effect of X-ray radiation showed 0.52 hours of an average life-span cut. But, based on prevalence, mortality and cure rate of chemotherapy for tuberculosis in Jiangsu Province, chest fluoroscopy in synthetic clue investigations brought an average prolongation of 45.8 hours per person in life-span of those X-rayed. Comparison of life-span showed synthetic clue investigation was an adequate method in active tuberculosis case-finding from the viewpoint of radiation protection.

[Estimations of organ dose and health risk of the mass chest X-ray examinations in children].

In Japan, mass chest X-ray examinations are mandated by law for schoolchildren and students. Recently, questions of the justification of such X-ray examination have arisen. In this study the absorbed doses of each organ, and the health detriments from the mass chest X-ray examinations to schoolchildren and students were estimated. The doses of organs were measured by the TLDs (Mg2SiO4), slab phantom, and anthropomorphic phantom. The probability of fatal cancer, and the resultant reduction in life expectancy induced by mass chest X-ray examinations were calculated by the multiplicative risk projection model of the ICRP-1990. The absorbed doses of lung, thyroid glands, esophagus, stomach, breast, and red bone marrow in first-year elementary schoolchildren were 90, 30, 90, 60, 90, and 30 muGy, respectively, and the doses in ovaries and testes were almost nil. Each organ dose of first-year students of junior high school was about 1.5 times that for elementary schoolchildren. The total radiation-induced lifetime cancer risk of schoolchildren and students was from 0.3 x 10(-5) to 0.9 x 10(-5) per person by the multiplicative risk projection model of the ICRP-1990 and a factor of 2 for the DDREF (dose and dose rate effectiveness factor). The reduction in life expectancy by radiation induced fatal cancer was from 15 x 10(-5) years to 50 x 10(-5) years per person. The results of this study suggest that subjects of mass chest X-ray examinations should be carefully selected from the viewpoint of radiation protection.

Population doses, excess deaths and loss of life expectancy from mass chest x-ray examinations in Japan--1980.

The number of mass chest x-ray examinations in Japan in 1980 was 26.6 million and the average effective dose equivalent was 26 mrem per examination. The genetically significant dose was .017 mrem per person per year, the per caput mean marrow dose was 5.9 mrem, the leukemia significant dose was 5.2 mrem and the malignancy significant dose was 2.8 mrem. The excess deaths were calculated to be 70-280 depending on the risk model used. Those would be in excess to the 3.7 million cancer deaths normally expected among the examined population. The loss of life expectancy calculated with a relative risk model was 38 yr for males and 43 yr for females due to leukemia with a latent period of 2 yr and an expression period of 25 yr, and 12 yr for males and 14 yr for females due to other cancers with a latent period of 10 yr and an expression period of lifetime in the 20-24 age group.

Abreugrafia e o risco das radiaçöes ionizantes / Abreugraphy and the risk of ionizing radiations

Discute-se a utilizaçäo da abreugrafia de forma indiscriminada como método de exame de massa, tendo em vista as elevadas doses de radiaçäo recebidas pelo paciente. Expöe-se os efeitos biológicos das radiaçöes ionizantes, advogando a extinçäo da obrigatoriedade do exame abreugráfico, imposta pelo artigo 168 da CLT aos trabalhadores brasileiros

Defects of the central nervous system in Finland. IV. Associations with diagnostic x-ray examinations.

Based on the Finnish Register of Congenital Malformations a search was undertaken to find possible associations between defects of the CNS and diagnostic x-ray examinations of the mother during pregnancy as well as pelvic x-ray examinations prior to pregnancy. Time-area--matched pregnancies and polydactylic children were used as controls. The risk of having a microcephalic child was increased for mothers with pelvic x-ray prior to pregnancy, but the number of discordant pairs was small. Of the examinations performed during pregnancy, fetal x-ray was significantly more common among mothers who delivered a CNS-defective child. No associations were observed for other kinds of examinations.