Increased lead concentrations in the hairs of radiographers in general hospitals.

This study investigated lead concentrations in the hairs of radiographers working in the radiological departments of general hospitals that used lead shielding for radiation protection. We collected scalp hair samples from 32 radiographers working in four radiology departments with lead shielding and 18 administration personnel in the same hospitals without lead shielding. Samples were analyzed for lead concentrations by inductively coupled plasma mass spectrometry. As a result, lead concentrations in the hairs of the radiological technologists were significantly higher than those in the administration staffs (0.72 ± 0.51 vs. 0.19 ± 0.27 µg/g, P < 0.001). The hair lead concentrations were positively and significantly associated with environmental lead concentrations (r = 0.6, P = 0.001), but not associated with age, working duration, and gender distribution.

Initial activity-related long-term outcome of iodine-131 treatment for thyroidectomy patients with differentiated thyroid carcinoma.

OBJECTIVE: To determine the outcome of iodine-131 (131I) treatment regimens in thyroidectomy patients with differentiated thyroid cancer. MATERIALS AND METHODS: Based on Taiwan's National Health Insurance Research Database (NHIRD) during the period from January 1, 2000 to December 31, 2010, 390 patients with well-differentiated thyroid cancer who underwent 131I treatment after thyroidectomy were enrolled in this study. Patients were classified into six groups according to the type of thyroidectomy and initial activity regimen of 131I treatment. The clinical outcome of 131I treatment was evaluated by total treatment number and medical expenditure, including costs for hospitalization and laboratory tests together with initial and subsequent 131I treatments. Multiple linear regression analysis was applied to analyze the factor(s) significantly affecting the outcome of 131I treatment. RESULTS: Increased activity of the initial 131I regimen reduced the total treatment number significantly for unilateral total thyroidectomy with initial 100-150mCi 131I, and mildly for bilateral total thyroidectomy with initial 100-150mCi 131I and radical thyroidectomy with initial 30-99mCi 131I. Increased activity of the initial 131I regimen reduced total medical expenditure significantly for unilateral, and mildly for bilateral total thyroidectomy both with initial 30-99mCi 131I. CONCLUSION: For patients with specific thyroidectomy for differentiated thyroid cancer, a high initial regimen of 131I treatment is more effective than the low activity regimen. An increased activity of the initial 131I regimen significantly reduced the total treatment number and medical expenditure.

Three Nuclear Medicine diagnostic procedures and breast cancer mortality in women. A population-analysis in Taiwan based upon National Health Insurance database.

OBJECTIVE: To investigate the correlation between the utilization of nuclear medicine diagnostic procedures and the mortality of women with breast cancer. SUBJECTS AND METHODS: Based on the National Health Insurance Research Database (NHIRD), we studied female breast cancer patients in 2012 who underwent whole-body bone scan, lymphoscintigraphy, or fluorine-18-fluorodeoxyglucose positron emission tomography/computed tomography (18F-FDG PET/CT) for possibly managing breast cancer metastases. The mortality of breast cancer was then followed up in 2017. Multiple linear regression analysis was applied to analyze the correlation between the use of any of these three nuclear medicine procedures and the mortality of breast cancer. RESULTS: For patients with early-stage breast cancer, single lymphoscintigraphy was the most frequently performed nuclear medicine procedure, accounting for 36.4% of all three nuclear medicine procedures. For patients with late-stage breast cancer, single whole-body bone scan was the most frequently performed nuclear medicine procedure, accounting for 67.2% of all three nuclear medicine procedures. Mortality of breast cancer significantly increased with the prevalence of late-stage breast cancer (b=2.87, P=0.001) and significantly decreased in cases in which whole-body bone scan was used (b=-4.28, P=0.003). CONCLUSION: The mortality of women with late-stage breast cancer was negatively related to the utilization of whole-body bone scan but not to the utilization of lymphoscintigraphy or the 18F-FDG PET/CT scan. In women with early-stage breast cancer, no significant correlation existed between breast cancer mortality and the utilization of the above three nuclear medicine procedures.

Trends in the utilization of nuclear medicine and radiopharmaceuticals in an aging population.

AIM: To investigate the trends in the utilization of nuclear medicine procedures and radiopharmaceuticals in an aging population and to establish the prediction models. METHODS: Based on Taiwan's National Health Insurance Research Database, a longitudinal study was conducted from 2000 to 2012. Descriptive statistics were adopted to analyze the frequencies and distributions of nuclear medicine procedures. Multiple linear regression analysis was applied to establish the prediction model for the utilization of nuclear medicine. RESULTS: The utilization of myocardial perfusion imaging increased most significantly, i.e. 250 per million population (pmp) increment annually, followed by the whole-body bone scan (176 pmp) and whole-body PET scan (100 pmp) in Taiwan during the period of 2000-2012. The use rate of nuclear medicine procedure which the first quartile (Q1) of age at examination above 35 years fits the regression model: Use rate expected year = 0.03 Q1 of age at examination × use rate baseline year + 14797 life expectancy expected year / life expectancy baseline year - 15030. Adversely, the use rate of procedure which Q1 of age at examination below 35 years fits the model: Use rate expected year = 0.01 Q1 of age at examination × use rate baseline year - 4565 life expectancy expected year / life expectancy baseline year + 4749. In addition, the similar models were found in the applications of radiopharmaceuticals. CONCLUSION: This study demonstrates the age at examination and life expectancy can be used to predict the utilities of nuclear medicine procedures and radiopharmaceuticals in an aging population. Nuclear medicine practice applied in the geriatrics would increase significantly with the aging of population.

Cancer risk from medical radiation procedures for coronary artery disease: a nationwide population-based cohort study.

To assess the risk of cancer incidence after medical radiation exposure for coronary artery disease (CAD), a retrospective cohort study was conducted based on Taiwan's National Health Insurance Research Database (NHIRD). Patients with CAD were identified according to the International Classification of Diseases code, 9th Revision, Clinical Modification (ICD-9-CM), and their records of medical radiation procedures were collected from 1997 to 2010. A total of 18,697 subjects with radiation exposure from cardiac imaging or therapeutic procedures for CAD were enrolled, and 19,109 subjects receiving cardiac diagnostic procedures without radiation were adopted as the control group. The distributions of age and gender were similar between the two populations. Cancer risks were evaluated by age-adjusted incidence rate ratio (aIRR) and association with cumulative exposure were further evaluated with relative risks by Poisson regression analysis. A total of 954 and 885 subjects with various types of cancers in both cohorts after following up for over 10 years were found, with incidences of 409.8 and 388.0 per 100,000 person-years, respectively. The risk of breast cancer (aIRR=1.85, 95% confidence interval: 1.14-3.00) was significantly elevated in the exposed female subjects, but no significant cancer risk was found in the exposed males. In addition, cancer risks of the breast and lung were increased with the exposure level. The study suggests that radiation exposure from cardiac imaging or therapeutic procedures for CAD may be associated with the increased risk of breast and lung cancers in CAD patients.

Myocardial perfusion scintigraphy in Taiwan from 2005 to 2009.

OBJECTIVE: To analyze the utilization of myocardial perfusion scintigraphy (MPS) in Taiwan within the universal healthcare system, the National Health Insurance (NHI) from 2005 to 2009, and to compare with European surveys. METHODS: On the basis of Taiwan's National Health Insurance Research Database of 2005-2009, a retrospective population-based analysis was conducted. Descriptive statistics were provided on the frequencies of and distributions in the utilization of MPS during the period. In addition, correlation analysis was applied to identify correlated factors in the utility of MPS. RESULTS: The annual number of MPS procedures performed was estimated to be 76 448 on average in 2005-2009 and 3361 per million population (pmp) over the period. The frequency increased by 45%, from 3008 pmp in 2005 to 4371 pmp in 2009, with an annual increase rate of 11.9%. The expenditure on MPS increased by 51%, from 12.3 million USD in 2005 to 18.55 million USD in 2009, with an annual increase rate of 12.9%. The average cost of identifying a coronary artery disease (CAD) case with MPS was 248 USD, with a 2.6% annual increase rate. Most patients were more than 50 years old when they received the MPS examination, whereas inpatients were much older. In addition, most of the MPS practices were performed in medical centers and regional hospitals, although an apparent increase was seen in district hospitals on outpatients. As a consequence, the rate of CAD diagnoses by MPS decreased over time. CONCLUSION: The numbers, frequencies, and expenses of MPS practices have increased in Taiwan during the period 2005-2009, especially for outpatients. The application rate of MPS in Taiwan was higher than that in Europe, likely because of the high accessibility to MPS procedures within the NHI system. This experience in Taiwan may serve as a reference for illustrating the trends in the use of MPS procedures in countries with a universal healthcare system.

Utilization of nuclear medicine scintigraphy in Taiwan, 1997-2009.

OBJECTIVE: To analyze the utilization of nuclear medicine scintigraphy in the Taiwanese population within the national health-care system between 1997 and 2009. METHODS: Based on the Taiwan's National Health Insurance Research Database of 1997-2009, a retrospective population-based analysis was conducted. Descriptive statistics and regression analysis were employed to analyze the frequencies and longitudinal trends in the utilization of diagnostic nuclear medicine procedures during the period. In addition, correlation analysis was applied to determine the correlated factors in the utility of nuclear medicine scintigraphy. RESULTS: The annual total nuclear medicine scintigraphy was estimated to be 256,389 on average in 1997-2009 and 11.7 per 1,000 population over the period. The frequency had increased by 67% over the years, from 8.2 per 1,000 population in 1997 to 13.7 per 1,000 population in 2009. The most frequently performed procedures were whole-body bone scans (33.4% of total) and myocardial perfusion scans (29.4% of total), with 4,615 and 5,620 increments per year, respectively. Most patients were in the age group of 41-65 years old when taking examinations. In addition, male subjects were slightly more than female patients (51.5 vs. 48.5%). Furthermore, the frequencies of whole-body bone scans and PET scans were proportional to the incidences of cancers (correlation coefficients were 0.96 and 0.94, respectively). CONCLUSIONS: The utilization of nuclear medicine scintigraphy with the National Health Insurance system in Taiwan has been changed considerably in the past 13 years. Both whole-body bone scan and myocardial perfusion scan were performed most often with significantly increases. The trend of nuclear medicine scintigraphy may have potential impact on making health-care policy in Taiwan.