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  • DKFZ Publication Database  (87)
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  • DKFZ Publication Database  (87)
Keywords
  • 1
    Keywords: SYSTEM ; PATIENT ; IMRT ; VERIFICATION ; FLUENCE ; PART
    Type of Publication: Book chapter
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  • 2
    Keywords: CALIBRATION ; treatment planning ; treatment ; CT ; heavy ion ; PART
    Type of Publication: Book chapter
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  • 3
    Keywords: VISUALIZATION ; imaging ; DISPLAY ; CALIBRATION
    Type of Publication: Book chapter
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  • 4
    Keywords: ENERGIES ; CANCER ; MODEL ; COHORT ; EPIDEMIOLOGY ; POPULATION ; RISK ; colon ; ASSOCIATION ; ACID ; ACIDS ; NO ; hormone ; ENERGY ; AGE ; WOMEN ; colorectal cancer ; MEN ; smoking ; COLORECTAL-CANCER ; COUNTRIES ; PROSTATE-CANCER ; cancer risk ; FIBER ; FRANCE ; COLON-CANCER ; MULTIVARIATE ; fatty acids ; FATTY-ACIDS ; DIETARY ; CANCER-RESEARCH ; CONSUMPTION ; European Prospective Investigation into Cancer and Nutrition ; FRUIT ; nutrition ; QUESTIONNAIRE ; CALIBRATION ; FOOD ; ASSOCIATIONS ; colon cancer ; WEIGHT ; CORONARY-HEART-DISEASE ; DIETARY-INTAKE MEASUREMENTS ; EPIC PROJECT ; HEIGHT
    Abstract: A link between unsaturated fatty acids or phytonutrients and reduced risk of colorectal cancer has been suggested. However, the effects of higher intake of dietary sources of these nutrients, such as the nuts and seeds food group, are less clear. The objective of this study was to determine the effects of nut and seed intake on colorectal cancer risk within the European Prospective Investigation into Cancer and Nutrition study, a large prospective cohort study involving 10 European countries. Total nut and seed intake was determined from country-specific dietary questionnaires. The data set included 478,040 subjects (141,988 men, 336,052 women) with a total of 855 (327 men, 528 women) colon and 474 (215 men, 259 women) rectal cancer cases. A multivariate Cox proportional hazards model, stratified by center and controlled for fruit intake, dietary fiber, energy, height, weight, sex, age, physical activity, and smoking, was used. The data show no association between higher intake of nuts and seeds and risk of colorectal, colon, and rectal cancers in men and women combined, but a significant inverse association was observed in subgroup analyses for colon cancer in women at the highest (〉6.2 g/d) versus the lowest (nonconsumers; hazard ratio, 0.69;, 95% confidence interval, 0.50-0.95) category of intake and for the linear effect of log-transformed intake (hazard ratio, 0.89; 95% confidence interval, 0.80-0.98), with no associations in men. It is not evident from this data why there may be a stronger association in women or why it may be limited to the colon, suggesting that much, further research is necessary
    Type of Publication: Journal article published
    PubMed ID: 15466975
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  • 5
    Keywords: CANCER ; Germany ; human ; MODEL ; COHORT ; RISK ; ASSOCIATION ; MEN ; COUNTRIES ; DIETARY ; ALCOHOL ; CONSUMPTION ; EPIC ; nutrition ; VEGETABLES ; CALIBRATION ; RELATIVE RISK ; REGRESSION ; ASSOCIATIONS ; LEVEL ; INTERVAL ; FRUITS ; fruits and vegetables ; prospective ; prospective study ; RECOMMENDATIONS ; EUROPEAN COUNTRIES ; CANCERS ; VARIABLES ; root vegetables ; SUBGROUPS ; upper aero-digestive cancer
    Abstract: Epidemiologic studies suggest that a high intake of fruits and vegetables is associated with decreased risk of cancers of the upper aero-digestive tract. We studied data from 345,904 subjects of the prospective European Investigation into Cancer and Nutrition (EPIC) recruited in seven European countries, who had completed a dietary questionnaire in 1992-1998. During 2,182,560 person years of observation 352 histologically verified incident squamous cell cancer (SCC) cases (255 males; 97 females) of the oral cavity, pharynx, larynx, and esophagus were identified. Linear and restricted cubic spline Cox regressions were fitted on variables of intake of fruits and vegetables and adjusted for potential confounders. We observed a significant inverse association with combined total fruits and vegetables intake (estimated relative risk (RR) = 0.91; 95% confidence interval (95% CI) 0.83-1.00 per 80 g/d of consumption), and nearly significant inverse associations in separate analyses with total fruits and total vegetables intake (RR: 0.97 (95% CI: 0.92-1.02) and RR = 0.89 (95% CI: 0.78-1.02) per 40 g/d of consumption). Overall, vegetable subgroups were not related to risk with the exception of intake of root vegetables in men. Restricted cubic spline regression did not improve the linear model fits except for total fruits and vegetables and total fruits with a significant decrease in risk at low intake levels (〈 120 g/d) for fruits. Dietary recommendations should consider the potential benefit of increasing fruits and vegetables consumption for reducing the risk of cancers of the upper aero-digestive tract, particularly at low intake
    Type of Publication: Journal article published
    PubMed ID: 16841263
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  • 6
    Keywords: OPTIMIZATION ; SIMULATIONS ; ASSOCIATION ; DESIGN ; ENERGY ; SELECTION ; FEASIBILITY ; FLUENCE ; MODULATED RADIATION-THERAPY ; MAGNETIC-FIELDS ; IMPT
    Abstract: The most recent experimental results obtained with laser-plasma accelerators are applied to radiotherapy simulations. The narrow electron beam, produced during the interaction of the laser with the gas jet, has a high charge (0.5 nC) and is quasimonoenergetic (170 +/- 20 MeV). The dose deposition is calculated in a water phantom placed at different distances from the diverging electron source. We show that, using magnetic fields to refocus the electron beam inside the water phantom, the transverse penumbra is improved. This electron beam is well suited for delivering a high dose peaked on the propagation axis, a sharp and narrow tranverse penumbra combined with a deep penetration. (c) 2006 American Association of Physicists in Medicine
    Type of Publication: Journal article published
    PubMed ID: 16485422
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  • 7
    Keywords: CANCER ; CELLS ; CELL ; Germany ; MODEL ; MODELS ; FOLLOW-UP ; SYSTEM ; cohort study ; DISEASE ; DISEASES ; EPIDEMIOLOGY ; RISK ; RISK-FACTORS ; ASSOCIATION ; NO ; LYMPHOMA ; HEALTH ; WOMEN ; etiology ; risk factors ; DIETARY ; UNITED-STATES ; ALCOHOL-CONSUMPTION ; CONSUMPTION ; FRUIT ; nutrition ; VEGETABLES ; CALIBRATION ; B-CELL LYMPHOMA ; MULTIPLE-MYELOMA ; NON-HODGKINS-LYMPHOMA ; ONCOLOGY ; DIETARY FACTORS ; ASSOCIATIONS ; IMMUNE-SYSTEM ; non-Hodgkin lymphoma ; INTERVAL ; FRUITS ; methods ; function ; prospective ; prospective study ; RISK-FACTOR ; HODGKIN LYMPHOMA ; B-CELL ; N-NITROSO COMPOUNDS ; DRINKING-WATER NITRATE
    Abstract: Introduction Lymphomas are a heterogeneous group of malignant diseases of cells of the immune system. The best-established risk factors are related to dys-regulation of immune function, and evidence suggests that factors such as dietary or lifestyle habits may be involved in the etiology. Material and methods In the European Prospective Investigation into Cancer and Nutrition (EPIC), 849 lymphoma cases were identified in a median follow-up period of 6.4 years. Fruit and vegetable consumption was estimated from validated dietary questionnaires. Cox proportional hazard models were used to examine the association between fruit and vegetable intake with the risk of lymphomas overall and subentities. Results There was no overall association between total fruit and vegetable consumption and risk of lymphoma [hazard ratio (HR) = 0.95, 95% confidence interval (CI) 0.78-1.15 comparing highest with lowest quartile]. However, the risk of diffuse large B-cell lymphomas (DLBCL) tended to be lower in participants with a high intake of total vegetables (HR = 0.49, 95% CI 0.23-1.02). Conclusion In this large prospective study, an inverse associations between fruit and vegetable consumption and risk of lymphomas overall could not be confirmed. Associations with lymphoma subentities such as DLBCL warrant further investigation
    Type of Publication: Journal article published
    PubMed ID: 17443415
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  • 8
    Keywords: CALIBRATION ; ultrasound ; 3D
    Abstract: OBJECTIVE: By adding a tracking sensor to a 3D ultrasound (US) probe and thus locating the probe in space, new applications within the fields of image guided surgery and radiation therapy are possible. To locate the US volume in space, a calibration is necessary to determine the mathematical transformation for mapping points from the tracking coordinate system to the US image coordinate system. We present a comprehensive comparison of two different approaches to perform this calibration for 3D US. METHODS: For both approaches a phantom is scanned and located in the images by means of segmentation and registration techniques. Calibration is then performed by either relating the tracked phantom's (TP) spatial location to the calibration scans, or by solely correlating scans taken from multiple perspectives when using hand-eye calibration methods (HE). Depending on which approach is utilized, a minimum of one or three images, respectively, need to be acquired for the calibration process. RESULTS: We evaluated both approaches for calibration and reconstruction precision. Regarding the latter, the performed tests led to mean target localization errors of 3.5 mm (HE) and 3.3 mm (TP) for real data, and of 1.4 mm (HE) and 0.9 mm (TP) for simulated data. CONCLUSION: Our results indicate that taking additional scans leads to a significant improvement in the calibration. Furthermore, the obtained calibration and reconstruction precisions suggest the use of a TP.
    Type of Publication: Journal article published
    PubMed ID: 20033620
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  • 9
    Keywords: SPECTRA ; Germany ; ALGORITHM ; CT ; IMAGES ; imaging ; SYSTEM ; TISSUE ; RESOLUTION ; radiation ; CONTRAST ; ENERGY ; tomography ; COMPUTED-TOMOGRAPHY ; CALIBRATION ; radiology ; ENHANCEMENT ; ACCURATE ; BONE ; PHANTOMS ; phantom ; COEFFICIENTS ; IGRT ; 3 ; WELL ; NOISE ; AIR GAPS ; CORRECTION ALGORITHM ; CT SCANNERS ; DIAGNOSTIC-RADIOLOGY ; DIGITAL RADIOGRAPHY ; fast beam hardening correction ; fast iterative scatter correction ; FLAT-PANEL IMAGER ; kV CBCT ; MONTE-CARLO SIMULATION ; RADIATION DISTRIBUTION ; X-RAY SCATTER
    Abstract: The problem of the enormous amount of scattered radiation in kV CBCT (kilo voltage cone beam computer tomography) is addressed Scatter causes undesirable streaks and cup-artifacts and results in a quantitative inaccuracy of reconstructed CT numbers, so that an accurate close calculation might be impossible Image contrast is also significantly reduced. Therefore we checked whether at? appropriate implementation of the fast iterative scatter correction algorithm we have developed for M V (mega voltage) CBCT reduces the scatter contribution in a kV CBCT as well. This scatter correction method is based on a superposition of pre-calculated Monte Carlo generated pencil beam scatter kernels. The algorithm requires only a system calibration by measuring homogeneous slab phantoms with known water-equivalent thicknesses.It this study we compare scatter corrected CBCT images of several phantoms to the fan beam CT images acquired with a reduced cone angle (a slice-thickness of 14 mm in the isocenter) at the same system. Additional measurements at a different CBCT system were made (different, energy spectrum and phantom-to-detector distance) and a first order approach of a fast beam hardening correction will be introduced. The observed image quality of the scatter corrected CBCT images is comparable concerning resolution, noise and contrast-to-noise ratio to the images acquired in fan beam geometry. Compared to the CBCT without any corrections the contrast of the contrast-and-resolution phantom with scatter correction and additional beam hardening correction is improved by a factor of about 1.5. The reconstructed attenuation coefficients and the CT numbers of the scatter corrected CBCT images are close to the values of the images acquired in fan beam geometry for the most pronounced tissue types. Only for extreme dense tissue types like cortical bone we see a difference in CT numbers of 5.2%, which can be improved to 4.4% with the additional beam hardening correction. Capping is reduced from 20% to 4% with scatter correction and 3% with an additional beam hardening correction. After 3 iterations (small phantoms,) and 6 to 7 iterations (large phantoms) the algorithm converges. Therefore the algorithm is very fast, that means 1.3 seconds per projection for 3 iterations, on a standard PC
    Type of Publication: Journal article published
    PubMed ID: 19761093
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  • 10
    Keywords: CANCER ; COMBINATION ; Germany ; COHORT ; DISEASE ; EXPOSURE ; POPULATION ; RISK ; CONTRAST ; ASSOCIATION ; ACID ; PATTERNS ; COUNTRIES ; SWEDEN ; DATABASE ; REGION ; FRANCE ; REGIONS ; POPULATIONS ; NETHERLANDS ; FUTURE ; PROJECT ; EPIC ; nutrition ; CALIBRATION ; nutrient intake ; VITAMIN-E ; RETINOL ; ASSOCIATIONS ; PATTERN ; SCIENCE ; methods ; dietary patterns ; prospective ; vitamin D ; VITAMIN-D ; ERRORS ; RATIONALE ; Vitamin E ; Exposure assessment
    Abstract: Until recently, the study of nutrient patterns was hampered at an international level by a lack of standardization of both dietary methods and nutrient databases. We aimed to describe the diversity of nutrient patterns in the European Prospective Investigation into Cancer and Nutrition (EPIC) study at population level as a starting point for future nutrient pattern analyses and their associations with chronic diseases in multi-center studies. In this cross-sectional study, 36,034 persons aged 35-74 y were administered a single, standardized 24-h dietary recall. Intake of 25 nutrients (excluding intake from dietary supplements) was estimated using a standardized nutrient database. We used a graphic presentation of mean nutrient intakes by region and sex relative to the overall EPIC means to contrast patterns within and between 10 European countries. In Mediterranean regions, including Greece, Italy, and the southern centers of Spain, the nutrient pattern was dominated by relatively high intakes of vitamin E and monounsaturated fatty acids (MUFA), whereas intakes of retinol and vitamin D were relatively low. In contrast, in Nordic countries, including Norway, Sweden, and Denmark, reported intake of these same nutrients resulted in almost the opposite pattern. Population groups in Germany, The Netherlands, and the UK shared a fatty acid pattern of relatively high intakes of PUFA and SFA and relatively low intakes of MUFA, in combination with a relatively high intake of sugar. We confirmed large variability in nutrient intakes across the EPIC study populations and identified 3 main region-specific patterns with a geographical gradient within and between European countries. J. Nutr. 140: 1280-1286, 2010
    Type of Publication: Journal article published
    PubMed ID: 20484545
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  • 11
    Keywords: CANCER ; MODEL ; MODELS ; FOLLOW-UP ; COHORT ; POPULATION ; INTERVENTION ; ASSOCIATION ; PATTERNS ; DESIGN ; ENERGY ; AGE ; WOMEN ; MEN ; OBESITY ; smoking ; COUNTRIES ; DIET ; FAT ; BLOOD-PRESSURE ; ALCOHOL ; PROJECT ; CONSUMPTION ; nutrition ; SMOKERS ; CALIBRATION ; MANAGEMENT ; physical activity ; ASSOCIATIONS ; PATTERN ; WEIGHT ; ENERGY-INTAKE ; LOW-CARBOHYDRATE ; PHYSICAL-ACTIVITY ; dietary patterns ; BODY-MASS INDEX ; prospective ; EUROPEAN COUNTRIES ; WAIST CIRCUMFERENCE ; WEIGHT CHANGE ; RANDOMIZED CLINICAL-TRIAL ; Lead ; Follow up ; weight gain ; OBESE ADULTS ; PLASMA LEPTIN ; PROTEIN DIET
    Abstract: Background: Meat intake may be related to weight gain because of its high energy and fat content. Some observational studies have shown that meat consumption is positively associated with weight gain, but intervention studies have shown mixed results. Objective: Our objective was to assess the association between consumption of total meat, red meat, poultry, and processed meat and weight gain after 5 y of follow-up, on average, in the large European population who participated in the European Prospective Investigation into Cancer and Nutrition-Physical Activity, Nutrition, Alcohol, Cessation of Smoking, Eating Out of Home and Obesity (EPIC-PANACEA) project. Design: A total of 103,455 men and 270,348 women aged 25-70 y were recruited between 1992 and 2000 in 10 European countries. Diet was assessed at baseline with the use of country-specific validated questionnaires. A dietary calibration study was conducted in a representative subsample of the cohort. Weight and height were measured at baseline and self-reported at follow-up in most centers. Associations between energy from meat (kcal/d) and annual weight change (g/y) were assessed with the use of linear mixed models, controlled for age, sex, total energy intake, physical activity, dietary patterns, and other potential confounders. Results: Total meat consumption was positively associated with weight gain in men and women, in normal-weight and overweight subjects, and in smokers and nonsmokers. With adjustment for estimated energy intake, an increase in meat intake of 250 g/d (eg, one steak at approximate to 450 kcal) would lead to a 2-kg higher weight gain after 5 y (95% CI: 1.5, 2.7 kg). Positive associations were observed for red meat, poultry, and processed meat. Conclusion: Our results suggest that a decrease in meat consumption may improve weight management. Am J Clin Nutr 2010; 92: 398-407
    Type of Publication: Journal article published
    PubMed ID: 20592131
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  • 12
    Keywords: CANCER ; COMBINATION ; Germany ; EPIDEMIOLOGY ; POPULATION ; PROTEIN ; PROTEINS ; PHOSPHORUS ; WOMEN ; COUNTRIES ; FATTY-ACIDS ; DIETARY ; CALCIUM ; ALCOHOL ; CONSUMPTION ; EPIC ; nutrition ; CALIBRATION ; FOOD ; nutrient intake ; BETA-CAROTENE ; NUTRIENTS ; RETINOL ; RECALL ; EPIC PROJECT ; IRON ; dietary patterns ; VITAMINS ; RECALLS ; POTASSIUM ; vitamin D ; 24-h dietary recall ; VEGETABLE-OIL ; magnesium ; nutrient intakes ; food component intakes ; food group combinations ; reduced rank regression
    Abstract: Objective: To identify combinations of food groups that explain as much variation in absolute intakes of 23 key nutrients and food components as possible within the country-specific populations of the European Prospective Investigation into Cancer and Nutrition (EPIC). Subjects/Methods: The analysis covered single 24-h dietary recalls (24-HDR) from 36 034 subjects (13 025 men and 23 009 women), aged 35-74 years, from all 10 countries participating in the EPIC study. In a set of 39 food groups, reduced rank regression (RRR) was used to identify those combinations (RRR factors) that explain the largest proportion of variation in intake of 23 key nutrients and food components, namely, proteins, saturated fatty acids, monounsaturated fatty acids, polyunsaturated fatty acids, cholesterol, sugars (sum of mono-and disaccharides), starch, fibre, alcohol, calcium, iron, potassium, phosphorus, magnesium, vitamin D, beta-carotene, retinol and vitamins E, B1, B2, B6, B12 and C (RRR responses). Analyses were performed at the country level and for all countries combined. Results: In the country-specific analyses, the first RRR factor explained a considerable proportion of the total nutrient intake variation in all 10 countries (27.4-37.1%). The subsequent RRR factors were much less important in explaining the variation (〈= 6%). Strong similarities were observed for the first country-specific RRR factor between the individual countries, largely characterized by consumption of bread, vegetable oils, red meat, milk, cheese, potatoes, margarine and processed meat. The highest explained variation was seen for protein, potassium, phosphorus and magnesium (50-70%), whereas sugars, beta-carotene, retinol and alcohol were only marginally explained (〈= 5%). The explained proportion of the other nutrients ranged between these extremes. Conclusions: A combination of food groups was identified that explained a considerable proportion of the nutrient intake variation in 24-HDRs in every country-specific EPIC population in a similar manner. This indicates that, despite the large variability in food and nutrient intakes reported in the EPIC, the variance of intake of important nutrients is explained, to a large extent, by similar food group combinations across countries.
    Type of Publication: Journal article published
    PubMed ID: 19888278
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  • 13
    Keywords: tomography ; SELECTION ; CALIBRATION ; SCATTER CORRECTION METHOD ; PRECORRECTION
    Abstract: PURPOSE: X-ray CT measures the attenuation of polychromatic x-rays through an object. The raw data acquired, which are the negative logarithm of the relative x-ray intensity behind the patient, must undergo water precorrection to linearize the measurement and to convert them into line integrals that are ready for reconstruction. The function to linearize the measured projection data depends on the detected spectrum of the ray. This spectrum may vary as a function of the detector position, e.g., in cases where the heel effect becomes relevant, where a bow-tie filter introduces channel-dependent beam hardening, or where a primary modulator is used to modulate the primary intensity of the spectrum. METHODS: The authors propose a new approach that allows to handle these effects in a highly convenient way. Their new empirical cupping correction for primary modulation (ECCP) corrects for artifacts, such as cupping artifacts or ring artifacts, which are induced by nonlinearities in the projection data due to spatially varying pre- or postfiltration of the x-rays. To do so, ECCP requires only a simple scan of a homogeneous phantom of nearly arbitrary shape. Based on this information, coefficients of a polynomial series are calculated and stored for later use. RESULTS: Physical measurements demonstrate the quality of the precorrection that can be achieved using ECCP to remove the cupping artifacts and to obtain well-calibrated CT values even in cases of strong primary modulation. A combination of ECCP with analytical techniques yielding a hybrid cupping correction method is possible and allows for channel-dependent correction functions. CONCLUSION: The proposed ECCP method is a very effective and easy to incorporate approach that compensates for even strong detector channel-dependent changes of the detected spectrum. (c) 2011 American Association of Physicists in Medicine.
    Type of Publication: Journal article published
    PubMed ID: 22320792
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  • 14
    Keywords: PROTECTION ; COHORT ; COLORECTAL-CANCER ; MEASUREMENT ERROR ; PROJECT ; CALIBRATION ; EPIDEMIOLOGIC EVIDENCE ; carbohydrate ; glycemic index ; NONSTARCH POLYSACCHARIDES
    Abstract: BACKGROUND: Earlier analyses within the EPIC study showed that dietary fibre intake was inversely associated with colorectal cancer risk, but results from some large cohort studies do not support this finding. We explored whether the association remained after longer follow-up with a near threefold increase in colorectal cancer cases, and if the association varied by gender and tumour location. METHODOLOGY/PRINCIPAL FINDINGS: After a mean follow-up of 11.0 years, 4,517 incident cases of colorectal cancer were documented. Total, cereal, fruit, and vegetable fibre intakes were estimated from dietary questionnaires at baseline. Hazard ratios (HRs) and 95% confidence intervals (CIs) were estimated using Cox proportional hazards models stratified by age, sex, and centre, and adjusted for total energy intake, body mass index, physical activity, smoking, education, menopausal status, hormone replacement therapy, oral contraceptive use, and intakes of alcohol, folate, red and processed meats, and calcium. After multivariable adjustments, total dietary fibre was inversely associated with colorectal cancer (HR per 10 g/day increase in fibre 0.87, 95% CI: 0.79-0.96). Similar linear associations were observed for colon and rectal cancers. The association between total dietary fibre and risk of colorectal cancer risk did not differ by age, sex, or anthropometric, lifestyle, and dietary variables. Fibre from cereals and fibre from fruit and vegetables were similarly associated with colon cancer; but for rectal cancer, the inverse association was only evident for fibre from cereals. CONCLUSIONS/SIGNIFICANCE: Our results strengthen the evidence for the role of high dietary fibre intake in colorectal cancer prevention.
    Type of Publication: Journal article published
    PubMed ID: 22761771
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  • 15
    Keywords: OPTIMIZATION ; PARAMETERS ; COMPUTED-TOMOGRAPHY ; CENTERS ; CALIBRATION ; RECONSTRUCTION ; ANALYTIC METHOD ; DOSE USAGE ; BACKPROJECTION ; MISALIGNMENT
    Abstract: PURPOSE: The authors propose a novel method for misalignment estimation of micro-CT scanners using an adaptive genetic algorithm. METHODS: The proposed algorithm is able to estimate the rotational geometry, the direction vector of table movement and the displacement between different imaging threads of a dual source or even multisource scanner. The calibration procedure does not rely on dedicated calibration phantoms and a sequence scan of a single metal bead is sufficient to geometrically calibrate the whole imaging system for spiral, sequential, and circular scan protocols. Dual source spiral and sequential scan protocols in micro-computed tomography result in projection data that-besides the source and detector positions and orientations-also require a precise knowledge of the table direction vector to be reconstructed properly. If those geometric parameters are not known accurately severe artifacts and a loss in spatial resolution appear in the reconstructed images as long as no geometry calibration is performed. The table direction vector is further required to ensure that consecutive volumes of a sequence scan can be stitched together and to allow the reconstruction of spiral data at all. RESULTS: The algorithm's performance is evaluated using simulations of a micro-CT system with known geometry and misalignment. To assess the quality of the algorithm in a real world scenario the calibration of a micro-CT scanner is performed and several reconstructions with and without geometry estimation are presented. CONCLUSIONS: The results indicate that the algorithm successfully estimates all geometry parameters, misalignment artifacts in the reconstructed volumes vanish, and the spatial resolution is increased as can be shown by the evaluation of modulation transfer function measurements.
    Type of Publication: Journal article published
    PubMed ID: 22957606
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  • 16
    Keywords: CANCER ; COHORT ; ACIDS ; OBESITY ; VALIDITY ; PROJECT ; CALIBRATION ; ADULTS ; PARTICIPANTS ; CUTOFF
    Abstract: Fish consumption is the major dietary source of EPA and DHA, which according to rodent experiments may reduce body fat mass and prevent obesity. Only a few human studies have investigated the association between fish consumption and body-weight gain. We investigated the association between fish consumption and subsequent change in body weight. Women and men (n 344 757) participating in the European Prospective Investigation into Cancer and Nutrition were followed for a median of 5.0 years. Linear and logistic regression were used to investigate the associations between fish consumption and subsequent change in body weight. Among women, the annual weight change was 5.70 (95% CI 4.35, 7.06), 2.23 (95% CI 0.16, 4.31) and 11.12 (95% CI 8.17, 14.08) g/10 g higher total, lean and fatty fish consumption per d, respectively. The OR of becoming overweight in 5 years among women who were normal weight at enrolment was 1.02 (95% CI 1.01, 1.02), 1.01 (95% CI 1.00, 1.02) and 1.02 (95% CI 1.01, 1.04) g/10 g higher total, lean and fatty consumption per d, respectively. Among men, fish consumption was not statistically significantly associated with weight change. Adjustment for potential over-or underestimation of fish consumption did not systematically change the observed associations, but the 95% CI became wider. The results in subgroups from analyses stratified by age or BMI at enrolment were not systematically different. In conclusion, the present study suggests that fish consumption has no appreciable association with body-weight gain.
    Type of Publication: Journal article published
    PubMed ID: 22716915
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  • 17
    Keywords: COHORT ; DISEASE ; RISK ; COLORECTAL-CANCER ; DIET ; CALIBRATION ; RED MEAT ; CERTIFICATES ; 21-YEAR FOLLOW-UP ; VEGETARIANS
    Abstract: BACKGROUND: Recently, some US cohorts have shown a moderate association between red and processed meat consumption and mortality supporting the results of previous studies among vegetarians. The aim of this study was to examine the association of red meat, processed meat, and poultry consumption with the risk of early death in the European Prospective Investigation into Cancer and Nutrition (EPIC). METHODS: Included in the analysis were 448,568 men and women without prevalent cancer, stroke, or myocardial infarction, and with complete information on diet, smoking, physical activity and body mass index, who were between 35 and 69 years old at baseline. Cox proportional hazards regression was used to examine the association of meat consumption with all-cause and cause-specific mortality. RESULTS: As of June 2009, 26,344 deaths were observed. After multivariate adjustment, a high consumption of red meat was related to higher all-cause mortality (hazard ratio (HR) = 1.14, 95% confidence interval (CI) 1.01 to 1.28, 160+ versus 10 to 19.9 g/day), and the association was stronger for processed meat (HR = 1.44, 95% CI 1.24 to 1.66, 160+ versus 10 to 19.9 g/day). After correction for measurement error, higher all-cause mortality remained significant only for processed meat (HR = 1.18, 95% CI 1.11 to 1.25, per 50 g/d). We estimated that 3.3% (95% CI 1.5% to 5.0%) of deaths could be prevented if all participants had a processed meat consumption of less than 20 g/day. Significant associations with processed meat intake were observed for cardiovascular diseases, cancer, and 'other causes of death'. The consumption of poultry was not related to all-cause mortality. CONCLUSIONS: The results of our analysis support a moderate positive association between processed meat consumption and mortality, in particular due to cardiovascular diseases, but also to cancer.
    Type of Publication: Journal article published
    PubMed ID: 23497300
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  • 18
    Keywords: POPULATION ; RISK ; IMPACT ; HEALTH ; MEN ; OXIDATIVE STRESS ; CALIBRATION ; HEART-DISEASE ; DIETARY ASSESSMENT ; CARDIOVASCULAR-DISEASE
    Abstract: In this study, the relation between fruit and vegetable consumption and mortality was investigated within the European Prospective Investigation Into Cancer and Nutrition. Survival analyses were performed, including 451,151 participants from 10 European countries, recruited between 1992 and 2000 and followed until 2010. Hazard ratios, rate advancement periods, and preventable proportions to respectively compare risk of death between quartiles of consumption, to estimate the period by which the risk of death was postponed among high consumers, and to estimate proportions of deaths that could be prevented if all participants would shift their consumption 1 quartile upward. Consumption of fruits and vegetables was inversely associated with all-cause mortality (for the highest quartile, hazard ratio = 0.90, 95% confidence interval (CI): 0.86, 0.94), with a rate advancement period of 1.12 years (95% CI: 0.70, 1.54), and with a preventable proportion of 2.95%. This association was driven mainly by cardiovascular disease mortality (for the highest quartile, hazard ratio = 0.85, 95% CI: 0.77, 0.93). Stronger inverse associations were observed for participants with high alcohol consumption or high body mass index and suggested in smokers. Inverse associations were stronger for raw than for cooked vegetable consumption. These results support the evidence that fruit and vegetable consumption is associated with a lower risk of death.
    Type of Publication: Journal article published
    PubMed ID: 23599238
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  • 19
    Keywords: radiotherapy ; MODEL ; TISSUE ; MONTE-CARLO SIMULATIONS ; CALIBRATION ; SINGLE ; dosimetry ; SCANNER ; PROTON STOPPING POWER ; CT NUMBERS
    Abstract: Inaccurate conversion of CT data to water-equivalent path length (WEPL) is one of the most important uncertainty sources in ion treatment planning. Dual energy CT (DECT) imaging might help to reduce CT number ambiguities with the additional information. In our study we scanned a series of materials (tissue substitutes, aluminum, PMMA, and other polymers) in the dual source scanner (Siemens Somatom Definition Flash). Based on the 80 kVp/140Sn kVp dual energy images, the electron densities rho(e) and effective atomic numbers Z(eff) were calculated. We introduced a new lookup table that translates the rho(e) to the WEPL. The WEPL residuals from the calibration were significantly reduced for the investigated tissue surrogates compared to the empirical Hounsfield-look-up table (single energy CT imaging) from (-1.0 +/- 1.8)% to (0.1 +/- 0.7)% and for non-tissue equivalent PMMA from -7.8% to -1.0%. To assess the benefit of the new DECT calibration, we conducted a treatment planning study for three different idealized cases based on tissue surrogates and PMMA. The DECT calibration yielded a significantly higher target coverage in tissue surrogates and phantom material (i.e. PMMA cylindo; mean target coverage improved from 62% to 98%). To verify the DECT calibration for real tissue, ion ranges through a frozen pig head were measured and compared to predictions calculated by the standard single energy CT calibration and the novel DECT calibration. By using this method, an improvement of ion range estimation from -2.1% water-equivalent thickness deviation (single energy CT) to 0.3% (DECT) was achieved. If one excludes raypaths located on the edge of the sample accompanied with high uncertainties, no significant difference could be observed.
    Type of Publication: Journal article published
    PubMed ID: 23597413
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  • 20
    Keywords: SYSTEM ; liver ; CALIBRATION ; ABLATION ; IMAGING INTERACTION TOOLKIT ; STANDARDIZED ASSESSMENT
    Abstract: PURPOSE: Intra-procedural acquisition of the patient anatomy is a key technique in the context of computer-assisted interventions (CAI). Ultrasound (US) offers major advantages as an interventional imaging modality because it is real time and low cost and does not expose the patient or physician to harmful radiation. To advance US-related research, the purpose of this paper was to develop and evaluate an open-source framework for US-based CAI applications. MATERIALS AND METHODS: We developed the open-source software module MITK-US for acquiring and processing US data as part of the well-known medical imaging interaction toolkit (MITK). To demonstrate its utility, we applied the module to implement a new concept for US-guided needle insertion. Performance of the US module was assessed by determining frame rate and latency for both a simple sample application and a more complex needle guidance system. RESULTS: MITK-US has successfully been used to implement both sample applications. Modern laptops achieve frame rates above 24 frames per second. Latency is measured to be approximately 250 ms or less. CONCLUSION: MITK-US can be considered a viable rapid prototyping environment for US-based CAI applications.
    Type of Publication: Journal article published
    PubMed ID: 24343000
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  • 21
    Keywords: COHORT ; RISK ; HEALTH ; nutrition ; CALIBRATION ; POSTMENOPAUSAL WOMEN ; RECEPTOR STATUS
    Abstract: We prospectively evaluated fat intake as predictor of developing breast cancer (BC) subtypes defined by estrogen receptor (ER), progesterone receptor (PR), and human epidermal growth factor 2 receptor (HER2), in a large (n = 337327) heterogeneous cohort of women, with 10062 BC case patients after 11.5 years, estimating BC hazard ratios (HRs) by Cox proportional hazard modeling. High total and saturated fat were associated with greater risk of ER(+)PR(+) disease (HR = 1.20, 95% confidence interval [CI] = 1.00 to 1.45; HR = 1.28, 95% CI = 1.09 to 1.52; highest vs lowest quintiles) but not ER(-)PR(-) disease. High saturated fat was statistically significantly associated with greater risk of HER2(-) disease. High saturated fat intake particularly increases risk of receptor-positive disease, suggesting saturated fat involvement in the etiology of this BC subtype.
    Type of Publication: Journal article published
    PubMed ID: 24718872
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  • 22
    Keywords: MODELS ; RISK ; DIETARY ; meat ; CALIBRATION ; CORONARY-HEART-DISEASE ; METAANALYSIS ; CONTAMINANTS ; DANISH ADULTS ; FISHERMEN
    Abstract: Fish is a source of important nutrients and may play a role in preventing heart diseases and other health outcomes. However, studies of overall mortality and cause-specific mortality related to fish consumption are inconclusive. We examined the rate of overall mortality, as well as mortality from ischaemic heart disease and cancer in relation to the intake of total fish, lean fish, and fatty fish in a large prospective cohort including ten European countries. More than 500,000 men and women completed a dietary questionnaire in 1992-1999 and were followed up for mortality until the end of 2010. 32,587 persons were reported dead since enrolment. Hazard ratios and their 99 % confidence interval were estimated using Cox proportional hazard regression models. Fish consumption was examined using quintiles based on reported consumption, using moderate fish consumption (third quintile) as reference, and as continuous variables, using increments of 10 g/day. All analyses were adjusted for possible confounders. No association was seen for fish consumption and overall or cause-specific mortality for both the categorical and the continuous analyses, but there seemed to be a U-shaped trend (p 〈 0.000) with fatty fish consumption and total mortality and with total fish consumption and cancer mortality (p = 0.046).
    Type of Publication: Journal article published
    PubMed ID: 25377533
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  • 23
    Keywords: EPIDEMIOLOGY ; LIPID-PEROXIDATION ; VEGETABLES ; CALIBRATION ; FOOD-FREQUENCY QUESTIONNAIRE ; pooled analysis ; KIDNEY CANCER ; COOKING ; RATIONALE ; 24-HOUR DIETARY RECALLS
    Abstract: Renal cell cancer (RCC) incidence varies worldwide with a higher incidence in developed countries and lifestyle is likely to contribute to the development of this disease. We examined whether meat and fish consumption were related to the risk of RCC in the European Prospective Investigation into Cancer and Nutrition (EPIC). The analysis included 493,179 EPIC participants, recruited between 1992 and 2000. Until December 2008, 691 RCC cases have been identified. Meat and fish consumption was assessed at baseline using country-specific dietary assessment instruments; 24-hour recalls were applied in an 8% subsample for calibration purposes. Cox proportional hazards regression was used to calculate multivariable-adjusted hazard ratios (HR) and 95% confidence intervals (CI). Women with a high consumption of red meat (HR=1.36, 95% CI 1.14-1.62; calibrated, per 50 g/day) and processed meat (HR=1.78, 95% CI 1.05-3.03; calibrated, per 50 g/day) had a higher risk of RCC, while no association existed in men. For processed meat, the association with RCC incidence was prominent in premenopausal women and was lacking in postmenopausal women (p interaction=0.02). Neither poultry nor fish consumption were statistically significantly associated with the risk of RCC. The results show a distinct association of red and processed meat consumption with incident RCC in women but not in men. A biological explanation for these findings remains unclear. What's new? Kidney cancer strikes different populations with different frequency, with developed nations seeing more cases. In this paper, the authors investigate whether certain elements of diet might correlate with increased incidence of renal cell carcinoma. Using data from the European Prospective Investigation into Cancer and Nutrition (EPIC), they assessed the amount of meat and fish consumed in populations representing a wide range of dietary habits. They then correlated this data with renal cell carcinoma incidence. They found no effect from eating fish; consuming red and processed meats did increase risk in women, but not in men.
    Type of Publication: Journal article published
    PubMed ID: 25258006
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  • 24
    Keywords: POPULATION ; METABOLISM ; smoking ; CONSUMPTION ; CALIBRATION ; antioxidants ; BETA-CAROTENE ; ALPHA-TOCOPHEROL ; SERUM ; COHORTS
    Abstract: Evidence of a protective effect of several antioxidants and other nutrients on pancreatic cancer risk is inconsistent. The aim of this study was to investigate the association for prediagnostic plasma levels of carotenoids, vitamin C, retinol and tocopherols with risk of pancreatic cancer in a case-control study nested within the European Prospective Investigation into Cancer and Nutrition (EPIC). 446 incident exocrine pancreatic cancer cases were matched to 446 controls by age at blood collection, study center, sex, date and time of blood collection, fasting status and hormone use. Plasma carotenoids (- and -carotene, lycopene, -cryptoxanthin, canthaxanthin, zeaxanthin and lutein), - and -tocopherol and retinol were measured by reverse phase high-performance liquid chromatography and plasma vitamin C by a colorimetric assay. Incidence rate ratios (IRRs) with 95% confidence intervals (95%CIs) for pancreatic cancer risk were estimated using a conditional logistic regression analysis, adjusted for smoking status, smoking duration and intensity, waist circumference, cotinine levels and diabetes status. Inverse associations with pancreatic cancer risk were found for plasma -carotene (IRR highest vs. lowest quartile 0.52, 95%CI 0.31-0.88, p for trend=0.02), zeaxanthin (IRR highest vs. lowest quartile 0.53, 95%CI 0.30-0.94, p for trend=0.06) and -tocopherol (IRR highest vs. lowest quartile 0.62, 95%CI 0.39-0.99, p for trend=0.08. For - and -carotene, lutein, sum of carotenoids and -tocopherol, heterogeneity between geographical regions was observed. In conclusion, our results show that higher plasma concentrations of -carotene, zeaxanthin and -tocopherol may be inversely associated with risk of pancreatic cancer, but further studies are warranted. What's new? Fruits and vegetables may play a role in the prevention of pancreatic cancer, but associations between the antioxidants those foods contain and disease risk remain unclear. In this study, pancreatic cancer risk was inversely associated with increased prediagnostic plasma concentrations of the antioxidants -carotene, zeaxanthin, and -tocopherol. Geographic variations were also detected. In Northern European countries, inverse associations with risk were found for blood levels of several carotenoids, whereas the association was strongest for -tocopherol in Southern European countries. The role of carotenoids and vitamins should be considered in subsequent investigations of the etiology of pancreatic cancer.
    Type of Publication: Journal article published
    PubMed ID: 25175624
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  • 25
    Keywords: POPULATION ; HEALTH ; WOMEN ; VALIDITY ; CALIBRATION ; METAANALYSIS ; PREMENOPAUSAL ; CAFFEINE CONSUMPTION ; SEX-HORMONE CONCENTRATIONS ; DECAFFEINATED COFFEE
    Abstract: INTRODUCTION: Specific coffee subtypes and tea may impact risk of pre- and post-menopausal breast cancer differently. We investigated the association between coffee (total, caffeinated, decaffeinated) and tea intake and risk of breast cancer. METHODS: A total of 335,060 women participating in the European Prospective Investigation into Nutrition and Cancer (EPIC) Study, completed a dietary questionnaire from 1992 to 2000, and were followed-up until 2010 for incidence of breast cancer. Hazard ratios (HR) of breast cancer by country-specific, as well as cohort-wide categories of beverage intake were estimated. RESULTS: During an average follow-up of 11 years, 1064 premenopausal, and 9134 postmenopausal breast cancers were diagnosed. Caffeinated coffee intake was associated with lower risk of postmenopausal breast cancer: adjusted HR = 0.90, 95% confidence interval (CI): 0.82 to 0.98, for high versus low consumption; P trend = 0.029. While there was no significant effect modification by hormone receptor status (P = 0.711), linear trend for lower risk of breast cancer with increasing caffeinated coffee intake was clearest for estrogen and progesterone receptor negative (ER-PR-), postmenopausal breast cancer (P = 0.008). For every 100 ml increase in caffeinated coffee intake, the risk of ER-PR- breast cancer was lower by 4% (adjusted HR: 0.96, 95% CI: 0.93 to 1.00). Non-consumers of decaffeinated coffee had lower risk of postmenopausal breast cancer (adjusted HR = 0.89; 95% CI: 0.80 to 0.99) compared to low consumers, without evidence of dose-response relationship (P trend = 0.128). Exclusive decaffeinated coffee consumption was not related to postmenopausal breast cancer risk, compared to any decaffeinated-low caffeinated intake (adjusted HR = 0.97; 95% CI: 0.82 to 1.14), or to no intake of any coffee (HR: 0.96; 95%: 0.82 to 1.14). Caffeinated and decaffeinated coffee were not associated with premenopausal breast cancer. Tea intake was neither associated with pre- nor post-menopausal breast cancer. CONCLUSIONS: Higher caffeinated coffee intake may be associated with lower risk of postmenopausal breast cancer. Decaffeinated coffee intake does not seem to be associated with breast cancer.
    Type of Publication: Journal article published
    PubMed ID: 25637171
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  • 26
    Keywords: CANCER ; EXPOSURE ; IDENTIFICATION ; MEASUREMENT ERROR ; CALIBRATION ; CARDIOVASCULAR-DISEASE ; 24-HOUR DIET RECALL ; FALSE DISCOVERY RATE ; COFFEE CONSUMPTION ; NUTRITIONAL BIOMARKERS
    Abstract: BACKGROUND: An improved understanding of the contribution of the diet to health and disease risks requires accurate assessments of dietary exposure in nutritional epidemiologic studies. The use of dietary biomarkers may improve the accuracy of estimates. OBJECTIVE: We applied a metabolomic approach in a large cohort study to identify novel biomarkers of intake for a selection of polyphenol-containing foods. The large chemical diversity of polyphenols and their wide distribution over many foods make them ideal biomarker candidates for such foods. DESIGN: Metabolic profiles were measured with the use of high-resolution mass spectrometry in 24-h urine samples from 481 subjects from the large European Prospective Investigation on Cancer and Nutrition cohort. Peak intensities were correlated to acute and habitual dietary intakes of 6 polyphenol-rich foods (coffee, tea, red wine, citrus fruit, apples and pears, and chocolate products) measured with the use of 24-h dietary recalls and food-frequency questionnaires, respectively. RESULTS: Correlation (r 〉 0.3, P 〈 0.01 after correction for multiple testing) and discriminant [pcorr (1) 〉 0.3, VIP 〉 1.5] analyses showed that 〉2000 mass spectral features from urine metabolic profiles were significantly associated with the consumption of the 6 selected foods. More than 80 polyphenol metabolites associated with the consumption of the selected foods could be identified, and large differences in their concentrations reflecting individual food intakes were observed within and between 4 European countries. Receiver operating characteristic curves showed that 5 polyphenol metabolites, which are characteristic of 5 of the 6 selected foods, had a high predicting ability of food intake. CONCLUSION: Highly diverse food-derived metabolites (the so-called food metabolome) can be characterized in human biospecimens through this powerful metabolomic approach and screened to identify novel biomarkers for dietary exposures, which are ultimately essential to better understand the role of the diet in the cause of chronic diseases.
    Type of Publication: Journal article published
    PubMed ID: 26269369
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  • 27
    Keywords: CANCER ; PROTEIN ; validation ; DIET ; DIETARY ; EPIC ; European Prospective Investigation into Cancer and Nutrition ; nutrition ; QUESTIONNAIRE ; questionnaires ; CALIBRATION ; 24-hour ; FOOD-INTAKE ; nutrient intake ; BETWEEN-SUBJECT ; DOUBLY-LABELED WATER ; LOW-ENERGY REPORTERS ; MULTICENTER COHORT ; NATIONAL-HEALTH ; SUBJECT VARIATION ; WEIGHED RECORDS ; WITHIN-SUBJECT
    Type of Publication: Journal article published
    PubMed ID: 12917211
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  • 28
    Keywords: EXPRESSION ; tumor ; Germany ; QUANTIFICATION ; SAMPLE ; SAMPLES ; TUMORS ; ACCURACY ; PATIENT ; DNA ; TISSUES ; PATTERNS ; MUTATION ; REQUIRES ; leukemia ; DNA methylation ; METHYLATION ; CALIBRATION ; CHRONIC LYMPHOCYTIC-LEUKEMIA ; HYPERMETHYLATION ; 5-METHYLCYTOSINE CONTENT ; HYPOMETHYLATION
    Abstract: Changes in DNA methylation have been found in the large majority of tumors. This phenomenon includes both genome-wide hypomethylation and gene-specific hypermethylation. However, the clinical relevance of either mechanism has remained contentious. In order to determine DNA methylation levels from a large number of clinical samples, we have established a method for accurate high-throughput quantification of 5- methylcytosine in genomic DNA. Our protocol requires a small amount (〈1 μg) of DNA that is enzymatically hydrolyzed to single nucleotides. Single nucleotides are then derivatized with a fluorescent marker and separated by capillary electrophoresis. After calibration of the method, we have determined cytosine methylation levels from tumor samples of 81 patients that had been diagnosed with chronic lymphocytic leukemia (CLL). These patients showed a high variability in their methylation levels with a general trend towards hypomethylation. Because of its high accuracy and throughput our method will be useful in determining the role of genomic DNA methylation levels in tumorigenesis
    Type of Publication: Journal article published
    PubMed ID: 12527791
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  • 29
    Keywords: CANCER ; carcinoma ; FOLLOW-UP ; COHORT ; cohort study ; RISK ; SITE ; INFECTION ; ASSOCIATION ; antibodies ; WOMEN ; MEN ; COUNTRIES ; DIET ; STOMACH ; adenocarcinoma ; case-control studies ; CARDIA ; CONSUMPTION ; EPIC ; GASTRIC-CANCER ; HELICOBACTER-PYLORI ; nutrition ; CALIBRATION ; case-control study ; INCREASE ; case control studies ; HELICOBACTER-PYLORI INFECTION ; prospective ; Helicobacter pylori ; intake ; FOODS
    Abstract: It is considered that fruit and vegetable (F&V) protect against oesophagus and gastric cancer (GC). However, 2 recent meta-analyses suggest that the strength of association on GC seems to he weaker for vegetables than for fruit and weaker in cohort than in case-control studies. No evidence exists from cohort studies about adenocarcinoma of oesophagus (ACO). In 521,457 men and women participating in the EPIC cohort in 10 European countries, information of diet and lifestyle was collected at baseline. After an average of 6.5 years of follow-up, a total of 330 GC and 65 ACO, confirmed and classified by a panel of pathologists, was used for the analysis. We examined the relation between F&V intake and GC and ACO. A calibration study in a sub-sample was used to control diet measurement errors. In a sub-sample of cases and a random sample of controls, antibodies against Helicobacter pylori (Hp) were measured and interactions with F&V were examined in a nested case-control study. We observed no association with total vegetable intake or specific groups of vegetables and GC risk, except for the intestinal type, where a negative association is possible regarding total vegetable (calibrated HR 0.66; 95% CI 0.35-1.22 per 100 g increase) and onion and garlic intake (calibrated HR 0.70; 95% CI 0.38-1.29 per 10 g increase). No evidence of association between fresh fruit intake and GC risk was observed. We found a negative but non significant association between citrus fruit intake and the cardia site (calibrated HR 0.77; 95% CI 0.47-1.22 per 100 g increase) while no association was observed with the non-cardia site. Regarding ACO, we found a non significant negative association for vegetable intake and for citrus intake (calibrated HRs 0.72; 95% Cl 0.32-1.64 and 0.77; 95% CI 0.46-1.28 per 100 and 50 g increase, respectively). It seems that lip infection does not modify the effect of F&V intake. Our study supports a possible protective role of vegetable intake in the intestinal type of GC and the ACO. Citrus fruit consumption may have a role in the protection against cardia GC and ACO. (c) 2005 Wiley-Liss, Inc
    Type of Publication: Journal article published
    PubMed ID: 16380980
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  • 30
    Keywords: CANCER ; GROWTH ; IN-VITRO ; human ; VITRO ; FOLLOW-UP ; COHORT ; incidence ; RISK ; RISK-FACTORS ; ASSOCIATION ; BREAST ; breast cancer ; BREAST-CANCER ; ACIDS ; HUMANS ; WOMEN ; risk factors ; cancer risk ; RECRUITMENT ; fatty acids ; DIETARY ; CONSUMPTION ; EPIC ; nutrition ; CALIBRATION ; RELATIVE RISK ; DIETARY-INTAKE ; SERUM PHOSPHOLIPIDS ; ADIPOSE-TISSUE ; POLYUNSATURATED FATTY-ACIDS ; POSTMENOPAUSAL WOMEN ; ASSOCIATIONS ; INTERVAL ; prospective ; MEAT INTAKE ; RISK-FACTOR ; CANCERS ; CANCER-RISK ; fish consumption ; N-3
    Abstract: There is current interest in fish consumption and marine omega-3 (n-3) fatty acids and breast cancer risk. Some in vitro and animal studies have suggested an inhibitory effect of marine n-3 fatty acids on breast cancer growth, but the results from epidemiological studies that have examined the association between fish consumption and breast cancer risk in humans are inconsistent. We examined fish consumption and breast cancer risk in 310,671 women aged between 25 and 70 yr at recruitment into the European Prospective Investigation Into Cancer and Nutrition (EPIC). The participants completed a dietary questionnaire between 1992-98 and were followed up for incidence of breast cancer for a median of 6.4 yr. Hazard ratio for breast cancer by intake of total and lean and fatty fish were estimated, stratified by study centre and adjusted for established breast cancer risk factors. During follow-up, 4,776 invasive incident breast cancers were reported. No significant associations between intake of total fish and breast cancer risk were observed, hazard ratio (HR) 1.01 (95% confidence interval [CI] 0.99-1.02; p = 0.28 per 10 g fish/day). When examining lean and ratty fish separately, we round a positive significant association only in the highest quintile for fatty fish (HR 1.13, 95% CI 1.01-1.26), but test for trend was not significant (p = 0.10). No associations with breast cancer risk were observed when the study participants were subdivided by menopausal status. Although the period of follow-up is relatively short, the results provide no evidence for an association between fish intake and breast cancer risk. (c) 2006 Wiley-Liss, Inc
    Type of Publication: Journal article published
    PubMed ID: 16470807
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  • 31
    Keywords: radiotherapy ; Germany ; CT ; VOLUME ; treatment ; PARTICLES ; NUMBER ; COMPUTED-TOMOGRAPHY ; treatment planning ; CALIBRATION ; RE ; BEAMS ; hip ; gold ; implant
    Abstract: In proton and ion radiotherapy, the range of particles is calculated from x-ray computed tomography (CT) numbers. Due to the strong absorption of x-rays in a metal and a cut-off for large Hounsfield units (HU) in the software of most CT-scanners, a range calculation in metals cannot be based on the measured HU. This is of special importance when metal implants such as gold fillings or hip prostheses are close to the treatment volume. In order to overcome this problem in treatment planning for heavy charged particles, the correct ranges of ions in the metal relative to water have to be assigned in the CT data. Measurements and calculations of carbon ion ranges in various metals are presented that can be used in treatment planning to allow for a more accurate range calculation of carbon ion beams in titanium, steel, tungsten and gold. The suggested values for the relative water-equivalent range and their uncertainties are 3.13 (+/- 3%) for titanium, 5.59 (+/- 3%) for stainless steel and 10.25 (+/- 4%) for gold
    Type of Publication: Journal article published
    PubMed ID: 16625027
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  • 32
    Keywords: Germany ; imaging ; INFORMATION ; NUCLEAR-MEDICINE ; NO ; BEAM ; nuclear medicine ; ELECTRON-BEAMS ; CALIBRATION ; radiology ; HIGH-ENERGY PHOTON ; ION CHAMBERS ; reference dosimetry ; NUCLEAR ; BEAMS ; ENGLAND ; MEDICINE ; - ; AAPM TG-51 ; GAMMA-RAY BEAMS ; IAEA TRS-398 ; MONTE-CARLO CALCULATIONS ; PLATE IONIZATION CHAMBERS
    Abstract: For plane- parallel chambers used in electron dosimetry, modern dosimetry protocols recommend a cross- calibration against a calibrated cylindrical chamber. The rationale for this is the unacceptably large ( up to 3 - 4%) chamber- to- chamber variations of the perturbation factors ( p(wall))(Co), which have been reported for plane- parallel chambers of a given type. In some recent publications, it was shown that this is no longer the case for modern plane- parallel chambers. The aims of the present study are to obtain reliable information about the variation of the perturbation factors for modern types of plane- parallel chambers, and - if this variation is found to be acceptably small - to determine type- specific mean values for these perturbation factors which can be used for absorbed dose measurements in electron beams using plane- parallel chambers. In an extensive multi- center study, the individual perturbation factors p(Co) ( which are usually assumed to be equal to (pwall)(Co)) for a total of 35 plane- parallel chambers of the Roos type, 15 chambers of the Markus type and 12 chambers of the Advanced Markus type were determined. From a total of 188 cross- calibration measurements, variations of the pCo values for different chambers of the same type of at most 1.0%, 0.9% and 0.6% were found for the chambers of the Roos, Markus and Advanced Markus types, respectively. The mean pCo values obtained from all measurements are (p) over bar (Roos)(Co) = 1.0198, (p) over bar (Markus)(Co) = 1.0175 and (p) over bar (Advanced)(Co) = 1.0155; the relative experimental standard deviation of the individual pCo values is less than 0.24% for all chamber types; the relative standard uncertainty of the mean p(Co) values is 1.1%
    Type of Publication: Journal article published
    PubMed ID: 18030000
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  • 33
    Keywords: CANCER ; evaluation ; Germany ; LUNG ; MODEL ; MODELS ; FOLLOW-UP ; INFORMATION ; lung cancer ; LUNG-CANCER ; COHORT ; EPIDEMIOLOGY ; incidence ; POPULATION ; RISK ; ASSOCIATION ; FREQUENCY ; FREQUENCIES ; NO ; smoking ; cancer risk ; MEASUREMENT ERROR ; MULTIVARIATE ; DIET ; INDIVIDUALS ; CONSUMPTION ; EPIC ; European Prospective Investigation into Cancer and Nutrition ; FRUIT ; nutrition ; VEGETABLES ; CALIBRATION ; LIFE-STYLE ; BETA-CAROTENE ; FOOD FREQUENCY QUESTIONNAIRE ; ALPHA-TOCOPHEROL ; ONCOLOGY ; ASSOCIATIONS ; RE ; INCREASE ; NONSMOKING WOMEN ; VITAMIN-C ; pooled analysis ; USA ; CANCER INCIDENCE ; prospective ; CANCER-RISK ; comparison ; ERROR ; CHINESE WOMEN ; DIETARY CAROTENOIDS
    Abstract: The association of fruit and vegetable consumption and lung cancer incidence was evaluated using the most recent data from the European Prospective Investigation into Cancer and Nutrition (EPIC), applying a refined statistical approach (calibration) to account for measurement error potentially introduced by using food frequency questionnaire data. Between 1992 and 2000, detailed information on diet and life-style of 478,590 individuals participating in EPIC was collected. During a median follow-up of 6.4 years, 1,126 lung cancer cases were observed. Multivariate Cox proportional hazard models were applied for statistical evaluation. In the whole study population, fruit consumption was significantly inversely associated with lung cancer risk while no association was found for vegetable consumption. In current smokers, however, lung cancer risk significantly decreased with higher vegetable consumption; this association became more pronounced after calibration, the hazard ratio (HR) being 0.78 (95% CI 0.620.98) per 100 g increase in daily vegetable consumption. In comparison, the HR per 100 g fruit was 0.92 (0.85-0.99) in the entire cohort and 0.90 (0.81-0.99) in smokers. Exclusion of cases diagnosed during the first 2 years of follow-up strengthened these associations, the HR being 0.71 (0.55-0.94) for vegetables (smokers) and 0.86 (0.78-0.95) for fruit (entire cohort). Cancer incidence decreased with higher consumption of apples and pears (entire cohort) as well as root vegetables (smokers). In addition to an overall inverse association with fruit intake, the results of this evaluation add evidence for a significant inverse association of vegetable consumption and lung cancer incidence in smokers. (C) 2007 Wiley-Liss, Inc
    Type of Publication: Journal article published
    PubMed ID: 17487840
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  • 34
    Keywords: CANCER ; evaluation ; MODEL ; MODELS ; COHORT ; DISEASE ; EXPOSURE ; incidence ; RISK ; validation ; IMPACT ; ASSOCIATION ; HEALTH ; WOMEN ; colorectal cancer ; MEN ; COLORECTAL-CANCER ; FISH ; REGION ; MEASUREMENT ERROR ; FRANCE ; REGIONS ; VARIABILITY ; DIET ; DIETARY ; SERIES ; OUTCOMES ; EPIC ; nutrition ; CALIBRATION ; FOOD ; DIETARY-INTAKE ; HETEROGENEITY ; MULTICENTER COHORT ; REGRESSION ; INCREASE ; DIETARY QUESTIONNAIRE ASSESSMENTS ; ENERGY-INTAKE ; LEVEL ; methods ; NUTRITIONAL EPIDEMIOLOGY ; CANCER INCIDENCE ; prospective ; ENGLAND ; SET ; outcome ; ERRORS ; RATIO ; VALUES ; European Prospective Investigation into Cancer ; hazard ratio ; CONFIDENCE-INTERVALS ; multicentre study ; TIME-SCALE
    Abstract: Background International multicentre studies on diet and cancer are relatively new in epidemiological research. They offer a series of challenging methodological issues for the evaluation of the association between dietary exposure and disease outcomes, which can both be quite heterogeneous across different geographical regions. This requires considerable work to standardize dietary measurements at the food and the nutrient levels. Methods Within the European Prospective Investigation into Cancer and Nutrition (EPIC), a calibration study was set up to express individual dietary intakes according to the same reference scale. A linear regression calibration model was used to correct the association between diet and disease for measurement errors in dietary exposures. In the present work, we describe an approach for analysing the EPIC data, using as an example the evaluation of the association between fish intake and colorectal cancer incidence. Results Sex- and country-specific attenuation factors ranged from 0.083 to 0.784, with values overall higher for men compared with women. Hazard ratio estimates of colorectal cancer for a 10 g/day increase in fish intake were 0.97 [95 confidence interval (CI): 0.950.99] and 0.93 (0.880.98), before and after calibration, respectively. Conclusions In a multicentre study, the diet/disease association can be evaluated by exploiting the whole variability of intake over the entire study. Calibration may reduce between-centre heterogeneity in the dietdisease relationship caused by differential impact of measurement errors across cohorts
    Type of Publication: Journal article published
    PubMed ID: 18180242
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  • 35
    Keywords: CANCER ; carcinoma ; CELL ; MODEL ; MODELS ; FOLLOW-UP ; COHORT ; RISK ; PROTEIN ; INDEX ; RISK-FACTORS ; ASSOCIATION ; ENERGY ; AGE ; WOMEN ; MEN ; smoking ; FIBER ; cholesterol ; DIET ; case-control studies ; ALCOHOL ; EPIC ; nutrition ; CALIBRATION ; NUTRIENTS ; physical activity ; CELL CARCINOMA ; renal cell carcinoma ; case-control study ; ENERGY-INTAKE ; prospective studies ; PHYSICAL-ACTIVITY ; USA ; dietary intake ; prospective ; prospective study ; INCREASED RISK ; carbohydrate ; FOODS ; KIDNEY CANCER ; macronutrients ; VITAMIN
    Abstract: Previous case-control studies have suggested that a high intake of animal foods and its associated nutrients are associated with an increased risk of renal cell carcinoma, although data from prospective studies are limited. We report here on the relationship between macronutrient intake and renal cell carcinoma incidence among 435,293 participants enrolled in the European Prospective Investigation into Cancer and Nutrition. Cox proportional hazard models were used to examine the association of dietary intake of fat, protein, carbohydrate, fiber and cholesterol and risk of renal cell carcinoma adjusted for age, sex, center, height, body mass index, physical activity, education, smoking, menopausal status, alcohol and energy intake. During an average 8.8 years of follow-up, 507 renal cell carcinoma cases occurred. Risk of renal cell carcinoma was not associated with macronutrient intake, including nutrients derived from animal sources. Our results indicate that macronutrient intake is not associated with risk of renal cell carcinoma in this cohort of European men and women. (C) 2009 UICC
    Type of Publication: Journal article published
    PubMed ID: 19415751
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    Keywords: SIMULATIONS ; BLOOD ; Germany ; LUNG ; MODEL ; PERFUSION ; imaging ; QUANTIFICATION ; VOLUME ; TISSUE ; ACCURACY ; validation ; TIME ; BLOOD-FLOW ; pig ; BODY-WEIGHT ; CONTRAST ; SIMULATION ; CONTRAST AGENT ; MRI ; SIGNAL ; MAGNETIC-RESONANCE ; magnetic resonance imaging ; ACID ; RELAXATION ; HUMANS ; REGION ; EXCHANGE ; PARAMETERS ; positron emission tomography ; POSITRON-EMISSION-TOMOGRAPHY ; tomography ; PET ; PULMONARY PERFUSION ; GD-DTPA ; CALIBRATION ; RECONSTRUCTION ; LUNG PERFUSION ; QUANTITATIVE ASSESSMENT ; AGENT ; radiology ; DEPENDENCE ; WEIGHT ; ENHANCED MRI ; intensity ; USA ; EMISSION-TOMOGRAPHY ; MYOCARDIAL-PERFUSION ; ERROR ; perfusion MRI ; Relaxation time ; WATER DIFFUSION
    Abstract: Validation of quantification of pulmonary blood flow (PBF) with dynamic, contrast-enhanced MRI is still missing. A possible reason certainly lies in difficulties based on the nonlinear dependence of signal intensity (SI) from contrast agent (CA) concentration. Both aspects were addressed in this study. Nine healthy pigs were examined by first-pass perfusion MRI using gadolinium diethylenetriamine pentaacetic acid (Gd-DTPA) and (H2O)-O-15 positron emission tomography (PET) imaging. Calculations of hemodynamic parameters were based on a one-compartment model (MR) and a two-compartment model (PET). Simulations showed a significant error when assuming a linear relation between MR SI and CA dose in the arterial input function (AIF), even at low doses of 0.025 mmol/kg body weight (BW). To correct for nonlinearity, a calibration curve was calculated on the basis of the signal equation. The required accuracy of equation parameters (like longitudinal relaxation time) was evaluated. Error analysis estimates 〈5% over-/underestimation of the corrected SI. Comparison of PET and MR flow values yielded a significant correlation (P 〈 0.001) in dorsal regions where signal-to-noise ratio (SNR) was sufficient. Changes in PBF due to the correction method were significant (P 〈 0.001) and resulted in a better agreement: mean values (standard deviation) in units of ml/min/100 ml lung tissue were 59 (15) for PET, 112 (28) for uncorrected MRI, and 80 (21) for corrected MRI. Magn Reson Med 62:476-487, 2009. (C) 2009 Wiley-Liss, Inc
    Type of Publication: Journal article published
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