Background: The U.S. National Lung Screening Trial (NLST) and Dutch-Belgian NELSON randomized con... more Background: The U.S. National Lung Screening Trial (NLST) and Dutch-Belgian NELSON randomized controlled trials have shown significant mortality reductions from low-dose computed tomography lung cancer screening (hereafter called LCS). NLST, ITALUNG, and COSMOS trials have provided detailed dosimetry data for LCS.
Methods: LCS trial mortality benefit results, organ dose and effective dose data, and BEIR VII organ dose-to-cancer-mortality risk data are used to estimate benefit-to-radiation-risk ratios of the NLST, ITALUNG, and COSMOS trials. Data from those trials also are used to estimate benefit-to-radiation risk ratios for longer-term LCS corresponding to scenarios recommended by USPSTF and the American Cancer Society.
Results: Including only screening doses, NLST benefit-to-radiation-risk ratios are 12:1 for males, 19:1 for females, and 16:1 overall. Including both screening and estimated follow-up doses, benefit-to-radiation-risk ratios for NLST are 9:1 for males, 13:1 for females, and 12:1 overall. For the ITALUNG trial, the benefit-to-radiation-risk ratio is 58-63:1. For the COSMOS trial, assuming sex-specific mortality benefits like those of the NELSON trial, the benefit-to-radiation-risk ratio is 21:1. Assuming a conservative 20% mortality benefit, annual screening in people 50-79 with a 20+ pack-year history of smoking has benefit-to-radiation-risk ratios of 23:1 (with follow-up doses adding 40% to screening doses) to 29:1 (with follow-up adding 10%) based on COSMOS dose data.
Conclusions: Based on linear, no threshold BEIR VII dose-risk estimates, benefit-to-radiation-risk ratios for LCS are highly favorable. Results emphasize the importance of using modern CT technologies, maintaining low follow-up rates, and minimizing both screening and follow-up doses.
This paper presents an analysis of signal-to-noise and contrast-to-noise ratios from small tip an... more This paper presents an analysis of signal-to-noise and contrast-to-noise ratios from small tip angle, gradient reversal (FLASH) imaging. Analytic and numerical techniques are used to determine the delay times and tip angles that maximize signal-to-noise per unit time from a single tissue. Similar procedures are used to determine the delay times and tip angles that maximize both T1-induced and T-2*-induced contrast-to-noise per unit time for a pair of tissues as a function of tissue characteristics and pulse sequence sampling times. The advantage of optimized FLASH imaging over optimized spin-echo imaging is quantitated by comparing signal-to-noise and contrast-to-noise ratios per unit time from the two sequences. Images are used to confirm these numerical results, to compare noise levels resulting from gradient reversals versus 180 degrees rephasing pulses and to assess the possible adverse effects of static magnetic field inhomogeneities on FLASH imaging.
Page 1. 1619 Benefit of Mammography Screening in Women Ages 40 to 49 Years Current Evidence from ... more Page 1. 1619 Benefit of Mammography Screening in Women Ages 40 to 49 Years Current Evidence from Randomized Controlled Trials Charles R. Smart, MD,* R. Edward Hendrick, Ph.D.,tJames H. Rutledge Ill, MS,$ and Robert A. Smith, Ph.D.5 Background. ...
Legislation on mammography in the United States has taken two forms: legislation on reimbursement... more Legislation on mammography in the United States has taken two forms: legislation on reimbursement for mammography and legislation on the quality of mammography. Legislation has been passed federally and in most states on these two issues (Fintor et al. 1995; McKinney et al. 1992).
... n刊he俯垢@o@Fe叫e叫n山n針山d@ons．S功@巾@nge川s什ngda匕SOU乍笛．呻山e廿noan』 帕@n ... were made on different detec... more ... n刊he俯垢@o@Fe叫e叫n山n針山d@ons．S功@巾@nge川s什ngda匕SOU乍笛．呻山e廿noan』 帕@n ... were made on different detector types or simulations were made for triore generic digital systems, not for the cesium-iodide silicoif diocfe array used in this study.f *. Williams et al ...
No studies have examined the associations of vitamin D and calcium intake with mammographic breas... more No studies have examined the associations of vitamin D and calcium intake with mammographic breast density in Hispanic women. Using the Southwest Food Frequency Questionnaire, we investigated these associations in a sample of 99 Hispanic women from the Chicago Breast Health Project Phase II Pilot Study. Using cutpoints based on recommended daily allowances, we classified women according to their intake
ABSTRACT Despite its technical advantages, early clinical trials comparing digital mammography wi... more ABSTRACT Despite its technical advantages, early clinical trials comparing digital mammography with film mammography for screening have been somewhat disappointing. Digital mammography,however, is in its infancy and can be expected to improve more rapidly than film mammography. Some areas of improvement being observed now include the development of new detector technologies; more powerful and better-designed interpretation workstations; and novel advanced applications, such as tomosynthesis and contrast-enhanced mammography, which are not possible with standard film mammography.
Mammographic breast density has been proposed as a surrogate endpoint in breast cancer prevention... more Mammographic breast density has been proposed as a surrogate endpoint in breast cancer prevention studies, but little is known about its variability over time, particularly in relation to menstrual cycle phase. The purpose of this study was to assess variation in breast density on digital mammograms using quantitative and qualitative density measures. Menstrual cycle phase was determined by salivary estradiol and progesterone assays. 73 healthy subjects with regular menses had 1-3 mammograms with paired saliva collection during a 12-month period. The mean difference in density as a percentage of the mean density was calculated for follicular-luteal (n = 50), luteal-luteal (n = 26) and follicular-follicular (n = 23) pairs in the same woman using the same breast. Two density measures (measurement of dense area and BIRADS) were used. The mean luteal density exceeded the mean follicular density by 7.1-9.2%, but density differences between luteal pairs and follicular pairs did not exceed 5%. The intraclass correlation for measurement of dense area was greater than 85% in all phases of the menstrual cycle, but was below 50% for BIRADS for luteal-follicular and follicular-follicular pairs. Our study provides estimates of the amount of variation in mammographic density during the menstrual cycle, and that inherent in repeated density measurement in premenopausal women, and suggests that menstrual phase of mammographic evaluation should be controlled for in intervention studies where density is being used as a surrogate measure.
Background: The U.S. National Lung Screening Trial (NLST) and Dutch-Belgian NELSON randomized con... more Background: The U.S. National Lung Screening Trial (NLST) and Dutch-Belgian NELSON randomized controlled trials have shown significant mortality reductions from low-dose computed tomography lung cancer screening (hereafter called LCS). NLST, ITALUNG, and COSMOS trials have provided detailed dosimetry data for LCS.
Methods: LCS trial mortality benefit results, organ dose and effective dose data, and BEIR VII organ dose-to-cancer-mortality risk data are used to estimate benefit-to-radiation-risk ratios of the NLST, ITALUNG, and COSMOS trials. Data from those trials also are used to estimate benefit-to-radiation risk ratios for longer-term LCS corresponding to scenarios recommended by USPSTF and the American Cancer Society.
Results: Including only screening doses, NLST benefit-to-radiation-risk ratios are 12:1 for males, 19:1 for females, and 16:1 overall. Including both screening and estimated follow-up doses, benefit-to-radiation-risk ratios for NLST are 9:1 for males, 13:1 for females, and 12:1 overall. For the ITALUNG trial, the benefit-to-radiation-risk ratio is 58-63:1. For the COSMOS trial, assuming sex-specific mortality benefits like those of the NELSON trial, the benefit-to-radiation-risk ratio is 21:1. Assuming a conservative 20% mortality benefit, annual screening in people 50-79 with a 20+ pack-year history of smoking has benefit-to-radiation-risk ratios of 23:1 (with follow-up doses adding 40% to screening doses) to 29:1 (with follow-up adding 10%) based on COSMOS dose data.
Conclusions: Based on linear, no threshold BEIR VII dose-risk estimates, benefit-to-radiation-risk ratios for LCS are highly favorable. Results emphasize the importance of using modern CT technologies, maintaining low follow-up rates, and minimizing both screening and follow-up doses.
This paper presents an analysis of signal-to-noise and contrast-to-noise ratios from small tip an... more This paper presents an analysis of signal-to-noise and contrast-to-noise ratios from small tip angle, gradient reversal (FLASH) imaging. Analytic and numerical techniques are used to determine the delay times and tip angles that maximize signal-to-noise per unit time from a single tissue. Similar procedures are used to determine the delay times and tip angles that maximize both T1-induced and T-2*-induced contrast-to-noise per unit time for a pair of tissues as a function of tissue characteristics and pulse sequence sampling times. The advantage of optimized FLASH imaging over optimized spin-echo imaging is quantitated by comparing signal-to-noise and contrast-to-noise ratios per unit time from the two sequences. Images are used to confirm these numerical results, to compare noise levels resulting from gradient reversals versus 180 degrees rephasing pulses and to assess the possible adverse effects of static magnetic field inhomogeneities on FLASH imaging.
Page 1. 1619 Benefit of Mammography Screening in Women Ages 40 to 49 Years Current Evidence from ... more Page 1. 1619 Benefit of Mammography Screening in Women Ages 40 to 49 Years Current Evidence from Randomized Controlled Trials Charles R. Smart, MD,* R. Edward Hendrick, Ph.D.,tJames H. Rutledge Ill, MS,$ and Robert A. Smith, Ph.D.5 Background. ...
Legislation on mammography in the United States has taken two forms: legislation on reimbursement... more Legislation on mammography in the United States has taken two forms: legislation on reimbursement for mammography and legislation on the quality of mammography. Legislation has been passed federally and in most states on these two issues (Fintor et al. 1995; McKinney et al. 1992).
... n刊he俯垢@o@Fe叫e叫n山n針山d@ons．S功@巾@nge川s什ngda匕SOU乍笛．呻山e廿noan』 帕@n ... were made on different detec... more ... n刊he俯垢@o@Fe叫e叫n山n針山d@ons．S功@巾@nge川s什ngda匕SOU乍笛．呻山e廿noan』 帕@n ... were made on different detector types or simulations were made for triore generic digital systems, not for the cesium-iodide silicoif diocfe array used in this study.f *. Williams et al ...
No studies have examined the associations of vitamin D and calcium intake with mammographic breas... more No studies have examined the associations of vitamin D and calcium intake with mammographic breast density in Hispanic women. Using the Southwest Food Frequency Questionnaire, we investigated these associations in a sample of 99 Hispanic women from the Chicago Breast Health Project Phase II Pilot Study. Using cutpoints based on recommended daily allowances, we classified women according to their intake
ABSTRACT Despite its technical advantages, early clinical trials comparing digital mammography wi... more ABSTRACT Despite its technical advantages, early clinical trials comparing digital mammography with film mammography for screening have been somewhat disappointing. Digital mammography,however, is in its infancy and can be expected to improve more rapidly than film mammography. Some areas of improvement being observed now include the development of new detector technologies; more powerful and better-designed interpretation workstations; and novel advanced applications, such as tomosynthesis and contrast-enhanced mammography, which are not possible with standard film mammography.
Mammographic breast density has been proposed as a surrogate endpoint in breast cancer prevention... more Mammographic breast density has been proposed as a surrogate endpoint in breast cancer prevention studies, but little is known about its variability over time, particularly in relation to menstrual cycle phase. The purpose of this study was to assess variation in breast density on digital mammograms using quantitative and qualitative density measures. Menstrual cycle phase was determined by salivary estradiol and progesterone assays. 73 healthy subjects with regular menses had 1-3 mammograms with paired saliva collection during a 12-month period. The mean difference in density as a percentage of the mean density was calculated for follicular-luteal (n = 50), luteal-luteal (n = 26) and follicular-follicular (n = 23) pairs in the same woman using the same breast. Two density measures (measurement of dense area and BIRADS) were used. The mean luteal density exceeded the mean follicular density by 7.1-9.2%, but density differences between luteal pairs and follicular pairs did not exceed 5%. The intraclass correlation for measurement of dense area was greater than 85% in all phases of the menstrual cycle, but was below 50% for BIRADS for luteal-follicular and follicular-follicular pairs. Our study provides estimates of the amount of variation in mammographic density during the menstrual cycle, and that inherent in repeated density measurement in premenopausal women, and suggests that menstrual phase of mammographic evaluation should be controlled for in intervention studies where density is being used as a surrogate measure.
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Papers by R. Hendrick
Methods: LCS trial mortality benefit results, organ dose and effective dose data, and BEIR VII organ dose-to-cancer-mortality risk data are used to estimate benefit-to-radiation-risk ratios of the NLST, ITALUNG, and COSMOS trials. Data from those trials also are used to estimate benefit-to-radiation risk ratios for longer-term LCS corresponding to scenarios recommended by USPSTF and the American Cancer Society.
Results: Including only screening doses, NLST benefit-to-radiation-risk ratios are 12:1 for males, 19:1 for females, and 16:1 overall. Including both screening and estimated follow-up doses, benefit-to-radiation-risk ratios for NLST are 9:1 for males, 13:1 for females, and 12:1 overall. For the ITALUNG trial, the benefit-to-radiation-risk ratio is 58-63:1. For the COSMOS trial, assuming sex-specific mortality benefits like those of the NELSON trial, the benefit-to-radiation-risk ratio is 21:1. Assuming a conservative 20% mortality benefit, annual screening in people 50-79 with a 20+ pack-year history of smoking has benefit-to-radiation-risk ratios of 23:1 (with follow-up doses adding 40% to screening doses) to 29:1 (with follow-up adding 10%) based on COSMOS dose data.
Conclusions: Based on linear, no threshold BEIR VII dose-risk estimates, benefit-to-radiation-risk ratios for LCS are highly favorable. Results emphasize the importance of using modern CT technologies, maintaining low follow-up rates, and minimizing both screening and follow-up doses.
Methods: LCS trial mortality benefit results, organ dose and effective dose data, and BEIR VII organ dose-to-cancer-mortality risk data are used to estimate benefit-to-radiation-risk ratios of the NLST, ITALUNG, and COSMOS trials. Data from those trials also are used to estimate benefit-to-radiation risk ratios for longer-term LCS corresponding to scenarios recommended by USPSTF and the American Cancer Society.
Results: Including only screening doses, NLST benefit-to-radiation-risk ratios are 12:1 for males, 19:1 for females, and 16:1 overall. Including both screening and estimated follow-up doses, benefit-to-radiation-risk ratios for NLST are 9:1 for males, 13:1 for females, and 12:1 overall. For the ITALUNG trial, the benefit-to-radiation-risk ratio is 58-63:1. For the COSMOS trial, assuming sex-specific mortality benefits like those of the NELSON trial, the benefit-to-radiation-risk ratio is 21:1. Assuming a conservative 20% mortality benefit, annual screening in people 50-79 with a 20+ pack-year history of smoking has benefit-to-radiation-risk ratios of 23:1 (with follow-up doses adding 40% to screening doses) to 29:1 (with follow-up adding 10%) based on COSMOS dose data.
Conclusions: Based on linear, no threshold BEIR VII dose-risk estimates, benefit-to-radiation-risk ratios for LCS are highly favorable. Results emphasize the importance of using modern CT technologies, maintaining low follow-up rates, and minimizing both screening and follow-up doses.