Deep learning-based segmentation for high-dose-rate brachytherapy in cervical cancer using 3D Prompt-ResUNet.

Objective.To develop and evaluate a 3D Prompt-ResUNet module that utilized the prompt-based model combined with 3D nnUNet for rapid and consistent autosegmentation of high-risk clinical target volume (HRCTV) and organ at risk (OAR) in high-dose-rate brachytherapy for cervical cancer patients.Approach.We used 73 computed tomography scans and 62 magnetic resonance imaging scans from 135 (103 for training, 16 for validation, and 16 for testing) cervical cancer patients across two hospitals for HRCTV and OAR segmentation. A novel comparison of the deep learning neural networks 3D Prompt-ResUNet, nnUNet, and segment anything model-Med3D was applied for the segmentation. Evaluation was conducted in two parts: geometric and clinical assessments. Quantitative metrics included the Dice similarity coefficient (DSC), 95th percentile Hausdorff distance (HD95%), Jaccard index (JI), and Matthews correlation coefficient (MCC). Clinical evaluation involved interobserver comparison, 4-grade expert scoring, and a double-blinded Turing test.Main results.The Prompt-ResUNet model performed most similarly to experienced radiation oncologists, outperforming less experienced ones. During testing, the DSC, HD95% (mm), JI, and MCC value (mean ± SD) for HRCTV were 0.92 ± 0.03, 2.91 ± 0.69, 0.85 ± 0.04, and 0.92 ± 0.02, respectively. For the bladder, these values were 0.93 ± 0.05, 3.07 ± 1.05, 0.87 ± 0.08, and 0.93 ± 0.05, respectively. For the rectum, they were 0.87 ± 0.03, 3.54 ± 1.46, 0.78 ± 0.05, and 0.87 ± 0.03, respectively. For the sigmoid, they were 0.76 ± 0.11, 7.54 ± 5.54, 0.63 ± 0.14, and 0.78 ± 0.09, respectively. The Prompt-ResUNet achieved a clinical viability score of at least 2 in all evaluation cases (100%) for both HRCTV and bladder and exceeded the 30% positive rate benchmark for all evaluated structures in the Turing test.Significance.The Prompt-ResUNet architecture demonstrated high consistency with ground truth in autosegmentation of HRCTV and OARs, reducing interobserver variability and shortening treatment times.

A Survey of Mean Glandular Doses and Suggestions on National Diagnostic Reference Levels for Digital Mammography in China.

ABSTRACT: The primary purpose of this study was to report the mean glandular doses and to determine the national diagnostic reference levels for digital mammography based on data between 2016 and 2018 in China. The data from 19,076 mammograms (4,769 examinations) by random sampling from 118 digital mammography systems were compiled. Exposure factors included age, compressed breast thickness, kVp, mAs, target/filter combination, entrance surface air kerma, and mean glandular doses, which were retrospectively surveyed and recorded from the monitor. The national diagnostic reference levels (75th percentiles) in mean glandular dose were calculated across median value obtained for all included data and stratified to specific compressed breast thickness ranges. The patients' ages ranged from 22 to 88 y, with a median age of 45. The applied voltage and output medians were 28 kVp and 75.1 mAs for all exposure, respectively. The median CBTs were 45 mm and 48 mm for craniocaudal views and mediolateral oblique views, and the corresponding median mean glandular doses were 1.32 mGy and 1.40 mGy, respectively. The national diagnostic reference level at compressed breast thickness of 40-50 mm was 1.67 mGy for CC views and 1.71 mGy for MLO views. The median mean glandular doses varied significantly and increased with compressed breast thickness, demonstrating the necessity of establishing DRL according to breast thickness and optimizing the clinic's digital mammography practice in China.

Measurements of 131I activity in thyroid of workers at the place of radioiodine therapy in 38 hospitals in China.

To investigate the levels of 131I activity in thyroid of workers at the place of radioiodine therapy and their main influential factors in China, 341 workers at 38 hospitals performing radioiodine therapy procedure in five provinces were recruited to be measured in 2021. A hand-held gamma spectrometer with NaI(Tl) probe was plastered to the thyroids and thighs of the subjects during the measurement, and each measurement time was 120 s. The internal exposure dose was calculated, and the committed effective dose was estimated. In 86 (25.22%) of the 341 examined workers, 131I thyroid activity was above minimum detectable activity (MDA, 26.6 Bq). The maximum activity was 4.9 × 103 Bq. The detection results above MDA were at 22 (57.89%) different hospitals. The detectable rate for private hospitals (4.8%) was significantly lower than that for public hospitals (26.6%), P < 0.05. The detectable rate for hospitals in provincial capital cities (15.4%) was significantly lower than in nonprovincial capital cities (41.7%), P < 0.001. The detectable rate for hospitals engaged in 131I therapy for thyroid cancer (31.2%) was significantly higher than only for hyperthyroidism (10.3%), P < 0.001. A total of 32 subjects' committed effective dose might exceed 1 mSv. Results indicated the 131I activity in the thyroid of workers at the place of radioiodine varied considerably in China, and mainly related to ownership, location and therapy program of the hospitals.

A deep learning-based 3D Prompt-nnUnet model for automatic segmentation in brachytherapy of postoperative endometrial carcinoma.

PURPOSE: To create and evaluate a three-dimensional (3D) Prompt-nnUnet module that utilizes the prompts-based model combined with 3D nnUnet for producing the rapid and consistent autosegmentation of high-risk clinical target volume (HR CTV) and organ at risk (OAR) in high-dose-rate brachytherapy (HDR BT) for patients with postoperative endometrial carcinoma (EC). METHODS AND MATERIALS: On two experimental batches, a total of 321 computed tomography (CT) scans were obtained for HR CTV segmentation from 321 patients with EC, and 125 CT scans for OARs segmentation from 125 patients. The numbers of training/validation/test were 257/32/32 and 87/13/25 for HR CTV and OARs respectively. A novel comparison of the deep learning neural network 3D Prompt-nnUnet and 3D nnUnet was applied for HR CTV and OARs segmentation. Three-fold cross validation and several quantitative metrics were employed, including Dice similarity coefficient (DSC), Hausdorff distance (HD), 95th percentile of Hausdorff distance (HD95%), and intersection over union (IoU). RESULTS: The Prompt-nnUnet included two forms of parameters Predict-Prompt (PP) and Label-Prompt (LP), with the LP performing most similarly to the experienced radiation oncologist and outperforming the less experienced ones. During the testing phase, the mean DSC values for the LP were 0.96 ± 0.02, 0.91 ± 0.02, and 0.83 ± 0.07 for HR CTV, rectum and urethra, respectively. The mean HD values (mm) were 2.73 ± 0.95, 8.18 ± 4.84, and 2.11 ± 0.50, respectively. The mean HD95% values (mm) were 1.66 ± 1.11, 3.07 ± 0.94, and 1.35 ± 0.55, respectively. The mean IoUs were 0.92 ± 0.04, 0.84 ± 0.03, and 0.71 ± 0.09, respectively. A delineation time < 2.35 s per structure in the new model was observed, which was available to save clinician time. CONCLUSION: The Prompt-nnUnet architecture, particularly the LP, was highly consistent with ground truth (GT) in HR CTV or OAR autosegmentation, reducing interobserver variability and shortening treatment time.

Trends of occupational exposure to ionizing radiation in Central China for the period 2000-2021.

A retrospective analysis of occupational exposure to ionizing radiation from medical uses and industrial uses in the three provinces of Central China from 2000 to 2021 was conducted. The average annual effective dose in medical uses and industrial uses decreased from 2.042 mSv and 2.334 mSv in 2000-2002 to 0.476 mSv and 0.371 mSv in 2021 respectively; the fraction of monitored workers receiving annual dose not exceeding 1 mSv increased from 60.78% and 74.45% in 2000-2002 to 94.20% and 96.85% in 2021 respectively, while receiving annual doses exceeding 20 mSv declined from 1.35% and 1.91% in 2000-2002 to 0.18% and 0.03% in 2021 respectively. The average annual effective dose and NR20 in the period 2000-2021 were relatively high in professional public health institutions (0.955 mSv and 0.004) and hospitals (0.815 mSv and 0.004). In 2021, the average annual effective dose to monitored workers in different occupational categories in medical uses in the three provinces of Central China were in the range of 0.199-0.692 mSv, with interventional radiology received the highest dose and NR20 (0.692 mSv and 0.005); the average annual effective dose ranged from 0.161 to 0.493 mSv in industrial uses, with industrial radiography received the highest dose and NR20 (0.493 mSv and 0.001). Occupational exposure in medical uses and industrial uses declined obviously in Central China, and the groups receiving higher doses are the radiation workers working in hospitals and professional public health institutions, or engaged in interventional radiology, nuclear medicine and industrial radiography, warranting more effective radiation protection measures.

DNA methylome profiling in occupational radon exposure miners using an Illumina Infinium Methylation EPIC BeadChip.

Background: A causal relationship between occupational radon exposure in underground miners and lung cancer risk has been demonstrated through large cohort epidemiological studies. However, the mechanisms by which radon exposure causes adverse effects on lung tissue remain unclear. Epigenetic alterations such as DNA methylation may provide new insights into interactions at molecular levels induced by prolonged radon exposure. Methods: We used the Illumina Infinium Human Methylation 850 K BeadChip to detect and compare genome-wide DNA methylation profiles in peripheral blood samples from underground miners (n = 14) and aboveground workers (n = 9). Results: The average concentration of radon in underground workplaces was significantly higher than that of aboveground places (1,198 Bq·m-3 vs 58 Bq·m-3, p < 0.001). A total of 191 differentially methylated positions (DMPs) corresponding to 104 hub genes were identified when |Δß| ≥ 0.1 and p < 0.05, with 107 hypermethylated sites and 84 hypomethylated sites. GO and KEGG analysis revealed that differentially methylated genes between underground miners and aboveground workers were prominently enriched in pathways/networks involved in neurotransmitter regulation, immunomodulatory effects and cell adhesion ability. Furthermore, methylation changes of selected genes FERMT1, ALCAM, HLA-DPA1, PON1 and OR2L13 were validated by pyrosequencing, which may play vital roles in these biological processes induced by radon. Conclusion: In summary, the DNA methylation pattern of the underground miners exposed to radon was distinct from that of the aboveground workers. Such abnormalities in the genomic DNA methylation profile associated with prolonged radon exposure are worth studying in terms of neuro- and immune-system regulation, as well as cell adhesion ability in the future.

Alteration of genome-wide DNA methylation in non-uranium miners induced by high level radon exposure.

In China, according to statistics about underground non-uranium mine radon levels, 15% exceed the national standard intervention level of 1000 Bq/m3, and some mines may exceed 10,000 Bq/m3. The relationship between radon exposure in underground miners and lung cancer has already been established, but the mechanisms and biological processes underlying it are poorly understood. In order to identify the genome-wide DNA methylation profile associated with long-term radon exposure, we performed the Infinium Human Methylation 850 K BeadChip measurement in whole blood samples obtained from 15 underground non-uranium miners and 10 matched aboveground control workers. Radon concentrations in the air of workplaces and living environments were measured by CR-39 radon detectors, and annual effective doses were calculated using the detection data. Under the high radon concentration with an average value of 12,700 Bq·m-3, a total of 165 significant differentially methylated positions (127 hypermethylated sites and 38 hypomethylated sites) annotated to 71 genes were identified in underground miners (|Δß| ≥ 0.10, p < 0.05), and the average DNA methylation level of 165 DMPs was significantly higher than that of the control workers. Most DMPs were found on chromosome 1, and approximately one-quarter of them were located in genomic promoter regions. Through bioinformatics analysis and pyrosequencing validation, five candidate genes differentially methylated by radon, including TIMP2, EMP2, CPT1B, AMD1 and SLC43A2 were identified. GO and KEGG analysis implicated that long term radon exposure could induce the lung cancer related biological processes such as cell adhesion and cellular polarity maintenance. Our study provides evidence for the alterations of genome-wide DNA methylation profiles induced by long-term high level radon exposure, and new insights into searching for carcinogenic biomarkers of high radon exposure in future studies.

Analysis of the Status of Radiation-generating Medical Devices in Mainland China.

ABSTRACT: The purpose of this paper is to describe the status of radiation-generating medical devices in mainland China. The number of diagnostic radiology and interventional radiology devices was collected from the national medical radiation protection monitoring information system, while the number of radiation therapy and nuclear medicine devices was from the published articles. Statistical analysis of the correlation was used to assess the relationship between the number of high technology medical devices and GDP per capita. A total of 143,064 radiation-generating medical devices were identified in mainland China, and diagnostic radiology devices accounted for 94% of those. The number of CTs was 14.84 per million, an increase by a factor of 1.45 compared to 2009. But the distribution of CTs was imbalanced among different areas: the highest number of CT per million population was 27.70 in Tibet, and the lowest was 8.55 per million population in Guangxi province. Statistical analysis of the correlation showed that the number of PET scanners per million population was positively correlated with GDP per capita, and similarly for medical accelerators. The number of mammographic devices per million population was much lower than that in other countries. The investment of radiation-generating medical devices in China was far from enough, especially for mammographic devices. More efforts should be taken to bring medical resources to regions with greater population areas in the future.Health Phys. 124(0):000-000; 2023.

Assessment of Occupational Exposure to Eye Lens Dosimetry for Interventional Radiology Workers in China during 2017-2019.

ABSTRACT: The eye lens is a sensitive tissue to ionizing radiation and recently has been recognized as more radiosensitive than previously considered. The International Commission on Radiological Protection (ICRP) has recommended a considerable reduction in the equivalent dose limit of eye lens from 150 mSv y -1 to 20 mSv y -1 , averaged over a defined period of 5 y. In this paper, the eye lens dose of interventional radiology workers in China during 2017-2019 is analyzed to understand the current status of eye lens occupational exposure and to provide decision-making suggestions for health supervision departments using data obtained from the National Radiological Health Information Platform in China. A total of 3,026 eye lens dose records of interventional radiology workers were collected. The average annual eye lens dose (AAELD) for interventional radiology workers ranged from 1.07 to 1.51 mSv during 2017-2019 and was 1.44 mSv for all monitored interventional radiology workers, with 2,973 records (98.2%) lower than the public limit of 15 mSv and 33 records (1.1%) exceeding the newly revised occupational eye lens dose limit of 20 mSv y -1 . During the period of 2017-2019, the AAELDs of interventional radiologists (1.61 mSv) and of interventional cardiologists (1.59 mSv) were significantly higher than that of other interventional workers (0.62 mSv); the AAELD of doctors (1.50 mSv) was significantly higher than that of nurses (1.01 mSv); the AAELD of western China (2.00 mSv) was significantly higher than that of eastern (1.11 mSv) and central China (1.27 mSv); and the AAELD of males (1.59 mSv) was significantly higher than that of females (0.84 mSv). The eye lens dose of interventional radiology workers meets the Chinese standard limit of 150 mSv y -1 , while some cases exceed the one recommended by ICRP. The study shows that the interventional radiology workers' eye lens dosimetry data complied with the existing Chinese eye lens dose limits. However, education, training, and supervision of radiation protection also should be strengthened continuously for interventional radiology workers, especially for the interventional radiologists and interventional cardiologists. Significant attention should be paid to the radiation protection of underdeveloped regions in China in future works.

ATM and TP53 polymorphisms modified susceptibility to radiation-induced lens opacity in natural high background radiation area, China.

Purpose: A population-based case-control study was conducted in Yangjiang and Enping areas in South China to assess whether the risk of lens opacity induced by natural high background radiation exposure is modulated by polymorphisms of ATM and TP53.Materials and methods: A total of 133 cases who were diagnosed with cortical and posterior subcapsular (PSC) opacity were recruited, and 419 healthy controls were selected through counter-matching in terms of radiation status. Genomic DNA from all the participants was genotyped with the Illumina platform for four single nucleotide polymorphisms of ATM (rs189037, rs373759, and rs4585) and TP53 (rs1042522). The cumulative lens dose received during the entire life was estimated based on annual indoor and outdoor radiation doses and gender- and age-specific occupancy factors. Non-conditional logistic regression was performed to calculate odds ratio (OR) and 95% confidence intervals (95% CI).Results:ATM rs189037 and TP53 rs1042522 were significantly related to cortical and PSC opacity. The risk of opacity was higher when individuals carried the A allele of ATM rs189037 and C allele of TP53 rs1042522, compared with GG genotype. ATM rs189037 A allele carriers (AG/AA) and TP53 rs1042522 C allele carriers (CG/CC) combined with a cumulative lens dose of 100 mGy or higher showed statistically significant opacity risks (OR = 5.51, 95% CI: 1.47-20.66; OR = 2.69, 95% CI: 1.10-6.60).Conclusion: The A allele of ATM rs189037 and C allele of TP53 rs1042522 increased the risk of lens opacity induced by radiation. These polymorphisms in ATM and TP53 might modify the risk of cortical and PSC opacity induced by chronic and prolonged low-dose radiation.

The First Attempt to Reevaluate Radon and Thoron Exposure in Gansu Province Study Using Radon-Thoron Discriminating Measurement Technique.

Although the epidemiological studies provide evidence for an increased risk of lung cancer risk associated with residential radon, an issue of radon-thoron discrimination remains to be solved. In this study, an updated evaluation of lung cancer risk among the residents in Gansu, China was performed where one of the major epidemiological studies on indoor radon demonstrated an increased risk of lung cancer. We analyzed data from a hospital-based case-control study that included 30 lung cancer cases and 39 controls with special attention to internal exposure assessment based on the discriminative measurement technique of radon isotopes. Results from the analyses showed non-significant increased lung cancer risks; odds ratios (ORs) adjusted for age, smoking, and total income were 0.35 (95% CI: 0.07-1.74) and 0.27 (95% CI: 0.04-1.74) for groups living in residences with indoor radon concentrations of 50-100 Bq m-3 and over 100 Bq m-3, respectively, compared with those with < 50 Bq m-3 indoor radon concentrations. Although the small sample size hampers the usefulness of present analyses, our study suggests that reevaluation of lung cancer risk associated with residential radon in the epidemiological studies will be required on the basis of precise exposure assessment.

Lens opacity prevalence among the residents in high natural background radiation area in Yangjiang, China.

The aim of the study was to evaluate the risk and threshold doses of lens opacity among residents exposed to low-dose radiation. Residents aged ≥45 years were recruited from a high natural background radiation (HNBR) area in Yangjiang City and a control area selected from nearby Enping City. Lens opacities (LOPs) were classified according to the Lens Opacities Classification System (LOCS) III system. Face-to-face interviews were conducted to collect information on lifestyles, migration and medical history. Life-time cumulative doses were estimated using gender, age, occupancy factors and environmental radiation doses received indoors and outdoors. Logistic regression analyses were conducted to estimate the dose response and determine thresholds. In the HNBR area, among 479 study participants, 101 (21.1%), 245(51.1%) and 23 cases (4.8%), respectively, of cortical, nuclear and posterior subcapsular (PSC) LOPs were found. In the control area, those types of LOPs were identified among 58 cases (12.6%), 206 cases (51.2%) and 6 cases (1.3%) of 462 examinees, respectively. Cumulative eye lens dose was estimated to be 189.5 ± 36.5 mGy in the HNBR area. Logistic analyses gave odds ratios at 100 mGy of 1.26 [95% confidence interval (CI) 1.00-1.60], 0.81 (95% CI 0.64-1.01) and 1.73 (95% CI 1.05-2.85) for cortical, nuclear and PSC LOPs, respectively. For cortical LOPs, a logistic analysis with a threshold dose gave a threshold estimate of 140 mGy (90% CI 110-160 mGy). The results indicated that population exposed to life-time, low-dose-rate environmental radiation was at an elevated risk of cortical and PSC LOPs. A statistically significant threshold dose was obtained for cortical LOPs and no threshold dose for PSC LOPs.

Trends of Annual Whole-body Occupational Radiation Exposure for Industrial Practices in China (2009-2018).

ABSTRACT: The national status and dose trends on the occupational exposure to ionizing radiation in industrial practices for 2009-2018 in China are presented in terms of seven occupational categories. A total of 504,538 industrial radiation workers were monitored for the period 2009-2018, with a continuous increase in the number of workers from 23,789 in 2009 to 66,017 in 2018. The annual average effective doses were 0.399, 0.425, 0.392, 0.376, 0.346, 0.355, 0.312, 0.305, 0.270, and 0.230 mSv from 2009 to 2018, respectively, which were well lower than the recommended occupational dose limit of 20 mSv y-1 for radiation workers. The Mann-Kendall test result shows a statistically significant decreasing trend at a rate of 0.02 mSv y-1 in average annual effective doses (p<0.001). In addition, more than 95.4% of radiation workers in industrial practices received an average annual effective dose less than the public dose limit of 1 mSv. It was also found that the average annual effective doses in industrial radiography and well logging were significantly higher than those in five other categories (p<0.001). Based on these observations, it is still necessary to control and manage the workplace and radiation workers to control occupational exposure as low as reasonably achievable, especially for the workers engaged in these two activities.

NATIONAL DOSE REGISTRY AND TRENDS OF OCCUPATIONAL EXPOSURE TO IONISING RADIATION IN CHINA (2009-2018).

The registry and analysis of occupational exposure is significant for radiation protection against ionising radiation. This paper presents the current status of the 'Chinese Registry of Radiation Workers (CRRW)' and trends as well as the distribution of occupational exposure to ionising radiation in China from 2009 to 2018. A database with total 6.6 million monitoring records from 820 000 workers in 85 000 radiation units for medical uses, industrial uses and miscellaneous uses is established by the CRRW. The Mann-Kendall test shows statistically significant decreasing trends of average annual effective dose for the total, medical uses and industrial uses (p < 0.01), by 0.035, 0.042 and 0.020 mSv/y, respectively. The average annual effective dose for the monitored workers is 0.403 mSv for the 10-y period. More than 96.1% of the monitored workers receive annual doses less than the limit for public exposure (1 mSv) in 2018. The annual average effective dose in medical uses is significantly higher than industrial uses and miscellaneous uses (p < 0.05/3 = 0.017). In 2018, the annual collective dose of 107.41 man·Sv is received by 378 428 monitored workers, with medical uses as the dominant contributor. These observations could be a result of improvements in radiation protection practices in China. However, it is still necessary to take rigorous and continuous surveillance and radiation protection measures, to keep individual dose as low as reasonably achievable, especially for those found to receive relatively higher doses in medical uses.

Cardiac catheterization procedures in children with congenital heart disease: Increased chromosomal aberrations in peripheral lymphocytes.

Cardiac catheterization procedures are performed on about 20,000 children with congenital heart disease (CHD) annually in China. The procedure, which involves exposure to ionizing radiation, causes DNA damage and may lead to increased cancer risk. We have studied chromosomal aberrations (CA) in peripheral lymphocytes of CHD children. CA frequencies were assessed in an interventional group of 70 children who underwent cardiac catheterization and a control group of 51 children receiving open-heart surgery. Total CA and all chromosome-type aberrations were higher in the exposed children than in the control group. With respect to the type of septal defect, the translocation frequency was higher in patients with ventricular rather than atrial defects. Cardiac catheterization procedures increase CA frequencies and may also increase the risk of cancer.

Trends and Distribution Analysis of Occupational Exposure From Medical Practices in China (2010-2016).

Occupational exposure to ionizing radiation from medical practices in China has been collected for a 7 y period between 2010 and 2016 from roughly 220 individual monitoring service providers through the Chinese Registry of Radiation Workers. Statistical dose distributions and characteristic tendencies are presented based on the evaluation in terms of six occupational categories. A reduction can be seen in average annual effective dose for interventional radiology, nuclear medicine, diagnostic radiology, radiotherapy, dental radiology, and others by 52%, 47%, 46%, 34%, 69%, and 31%, respectively, for the 7 y period. More than 94.5% of radiation workers received annual doses less than the public dose limit (1 mSv) in 2016. Workers engaged in nuclear medicine and interventional radiology activities were found to receive relatively more dose than the other fields of practice. Diagnostic radiology makes the dominant contribution of 68% to the collective effective dose of 73,641.3 person mSv received by 211,613 radiation workers in medical practices in 2016. The observation of workers in medical practices receiving well below the recommended occupational dose limit (20 mSv) could be a result of an improvement in radiation protection practices in the medical field in China. However, it is still necessary to control and manage the workplace and radiation workers to avoid unnecessary exposures, in particular for the workers engaged in nuclear medicine and interventional radiology activities.

Long-term immune effects of high-level natural radiation on Yangjiang inhabitants in China.

Purpose: Low dose radiation was found to perturb immune function or inflammatory reactions, which required further study. This study aimed to evaluate the health effects following long-term low dose radiation by detecting levels of peripheral blood lymphocyte subsets and serum cytokines of residents living in the Yangjiang High Background Radiation Area (HBRA). Materials and methods: Flow cytometry was used to detect peripheral blood T lymphocytes and its subsets (CD4+ T, CD8+ T lymphocyte) in 100 healthy female residents selected from HBRA and a Control Area (CA), respectively. Thirty cytokines or receptors and CRP levels were measured using antibody arrays in the 40 subjects described above. Subjects were chosen based on an age and BMI match between the two groups. Cytokine expression levels were then verified using ELISA methods. Result: In comparison to CA, CD8+ T lymphocyte numbers were significantly increased with cumulative dose following adjustment to age and BMI. Of the 30 selected targets, 22 indexes were measurable and inflammatory cytokines such as IFN-γ, IL-α, MCP-1, sIL-6R, EGFR, and CRP levels were observed to be significantly up-regulated with cumulative doses. ELISA results confirmed the cytokine array results and found CRP, MCP-1, and sIL-6R levels are linear with cumulative dose following adjustment to age and BMI. Conclusion: Immune function was found to be affected in humans exposed to long-term low dose radiation. Specifically, we observed an increase in CD8+T lymphocyte numbers and an up-regulation of inflammatory biomarkers, including IFN-γ, MCP-1, sIL-6R, EGFR, CRP.

Estimation of the occupational exposure dose for medical diagnostic X-ray workers in Jiangsu, China, using a retrospective dosimetry method.

Medical diagnostic X-ray workers are one occupational group that has exposure to continuous low doses of external radiation over their working lifetimes. Current ICRP recommendations [ICRP. Recommendations of the International Commission on Radiological Protection. ICRP Publication 60. Ann ICRP 1991;21 (1-3)] state that there is no threshold of stochastic effects induced by radiation exposure such as carcinogenicity or genetic defects, and that the frequency of the effects is proportional to the amount of exposure to low levels of radiation, which is measured by radiation dose. In order to determine the dose information for this special occupational group over their working lifetimes (focusing particularly on workers exposed before 1985, when there was no personal dose monitoring), a sampling survey of the occupational history for these workers was conducted and an occupational history database was established. Using the database and retrospective dosimetry method of Zhang et al. (A retrospective dosimetry method for occupational dose for Chinese medical diagnostic X-ray workers. Radiat Prot Dosimetry 1998;77:69-72), the annual occupational exposure dose for medical diagnostic X-ray personnel working between 1950 and 2011 was computerized. Some annual dose results estimated using the proposed method were numerically in good agreement with the monitoring results. The average of the annual dose for these medical workers peaked during the mid-1950s and then declined, reaching very low levels by the 1990s and remaining at those levels thereafter. The trend in the annual dose is similar to that reported by earlier studies by Zielinski et al. (Health outcomes of low-dose ionizing radiation exposure among medical workers: a cohort study of the Canadian national dose registry of radiation workers. Int J Occup Med Environ Health 2009;22:149-56). The dose calculated by the retrospective dosimetry method can truly indicate the degree of the workers' exposure in their medical X-ray diagnostic work.

Nested Case-control Study of Occupational Radiation Exposure and Breast and Esophagus Cancer Risk among Medical Diagnostic X Ray Workers in Jiangsu of China.

Medical diagnostic X-ray workers are one occupational group that expose to the long-term low-dose external radiation over their working lifetime, and they may under risk of different cancers. This study aims to determine the relationship between the occupational X-ray radiation exposure and cancer risk among these workers in Jiangsu, China. We conducted Nested case-control study to investigate the occupational X-ray radiation exposure and cancer risk. Data were collected through self-administered questionnaire, which includes but not limits to demographic data, personal behaviors and family history of cancer. Retrospective dose reconstruction was conducted to estimate the cumulative doses of the x-ray workers. Inferential statistics, t-test and 2 tests were used to compare the differences between each group. We used the logistic regression model to calculate the odds ratio (OR) and 95% confidence interval (CI) of cancer by adjusting the age, gender. All 34 breast cancer cases and 45 esophageal cancer cases that detected in a cohort conducted among health workers between 1950~2011 were included in this presented study, and 158 cancer-free controls were selected by frequency-matched (1:2). Our study found that the occupational radiation exposure was associated with a significantly increased cancer risk compared with the control, especially in breast cancer and esophageal cancer (adjusted OR=2.90, 95% CI: 1.19-7.04 for breast cancer; OR=4.19, 95% CI: 1.87-9.38 for esophageal cancer, and OR=3.43, 95% CI: 1.92-6.12 for total cancer, respectively). The occupational X-ray radiation exposure was associated with increasing cancer risk, which indicates that proper intervention and prevention strategies may be needed in order to bring down the occupational cancer risk.