Mammography and 99mTc-MIBI scintimammography in suspected breast cancer.
The aim of this work has been to evaluate whether a diagnostic protocol based on the joint use of mammography and 99mTc-methoxyisobutyl isonitrile (MIBI) scintimammography is capable of reducing the number of biopsies required in patients with suspected breast cancer. METHODS: We performed prone scintimammography in 90 patients with suspected breast cancer, involving 97 lesions. In all patients, the diagnosis was established by way of biopsy. On mammography, we evaluated the degree of suspicion of malignancy and the size of the lesion (smaller or larger than 1 cm in diameter). RESULTS: The results of only 41 of the biopsies indicated malignancy. On mammography, 20 lesions (of which 1 was breast cancer) were considered to be of low suspicion of malignancy, 31 (of which 4 were breast cancer) as indeterminate and 46 (of which 36 were breast cancer) as high. Fourteen lesions (2 low probability, 2 indeterminate and 10 high) were smaller than 1 cm, whereas 83 (18 low probability, 29 indeterminate and 36 high) were larger. The sensitivity, specificity, positive predictive value and negative predictive value of scintimammography were 85%, 79%, 74% and 88%, respectively. Scintimammography was positive in all cases of breast cancer that initially had a low or indeterminate suspicion of malignancy according to mammography, as well as in 30 cases of breast cancer that initially were highly suspicious. Six false-negative scintimammography studies were obtained in lesions with a high suspicion of malignancy. CONCLUSION: We propose a diagnostic protocol with a biopsy performed on lesions that have a high suspicion of malignancy as well as those with low or indeterminate suspicion that are smaller than 1 cm or with positive scintimammography results. This would have reduced the total number of biopsies performed by 34%. More importantly, there would have been a 65% reduction in number of biopsies performed in the low and indeterminate mammographic suspicion groups. All 41 cases of breast cancer would have been detected. (+info)
The effect of the antiscatter grid on full-field digital mammography phantom images.
Computer Analysis of Mammography Phantom Images (CAMPI) is a method for making quantitative measurements of image quality. This article reports on a recent application of this method to a prototype full-field digital mammography (FFDM) machine. Images of a modified ACR phantom were acquired on the General Electric Diagnostic Molybdenum Rhodium (GE-DMR) FFDM machine at a number of x-ray techniques, both with and without the scatter reduction grid. The techniques were chosen so that one had sets of grid and non-grid images with matched doses (200 mrads) and matched gray-scale values (1500). A third set was acquired at constant 26 kVp and varying mAs for both grid conditions. Analyses of the images yielded signal-to-noise-ratio (SNR), contrast and noise corresponding to each target object, and a non-uniformity measure. The results showed that under conditions of equal gray-scale value the grid images were markedly superior, albeit at higher doses than the non-grid images. Under constant dose conditions, the non-grid images were slightly superior in SNR (7%) but markedly less uniform (60%). Overall, the grid images had substantially greater contrast and superior image uniformity. These conclusions applied to the whole kVp range studied for the Mo-Mo target filter combination and 4 cm of breast equivalent material of average composition. These results suggest that use of the non-grid technique in digital mammography with the GE-DMR-FFDM unit, is presently not warranted. With improved uniformity correction procedure, this conclusion would change and one should be able to realize a 14% reduction in patient dose at the same SNR by using a non-grid technique. (+info)
Screening Mammography Program of British Columbia: pattern of use and health care system costs.
BACKGROUND: The use of mammography for screening asymptomatic women has increased dramatically in the past decade. This report describes the changes that have occurred in the use of bilateral mammography in British Columbia since the provincial breast cancer screening program began in 1988. METHODS: Using province-wide databases from both the breast cancer screening program and the provincial health insurance plan in BC, the authors determined the number and costs of bilateral mammography services for women aged 40 years or older between Apr. 1, 1986, and Mar. 31, 1997. Unilateral mammography was excluded because it is used for investigating symptomatic disease and screening abnormalities, and for follow-up of women who have undergone mastectomy for cancer. RESULTS: As the provincial breast cancer screening program expanded from 1 site in 1988 to 23 in 1997, it provided an increasing proportion of the bilateral mammographic examinations carried out each year in BC. In fiscal year 1996/97, 65% of bilateral mammographic examinations were performed through the screening program. The cost per examination within the screening program dropped as volume increased. Thirty percent more bilateral mammography examinations were done in 1996/97 than in 1991/92, but health care system expenditures for these services increased by only 4% during the same period. In calendar year 1996, 21% of new breast cancers were diagnosed as a result of a screening program visit. INTERPRETATION: Substantial increases in health care expenditures have been avoided by shifting bilateral mammography services to the provincial screening program, which has a lower cost per screening visit. (+info)
Moderate physical activity in relation to mammographic patterns.
High-risk mammographic patterns may be used as a surrogate end point for breast cancer in etiologic research as well as in prevention studies. Physical activity may be one of the few modifiable risk factors for breast cancer. We examined the relationship between physical activity and mammographic patterns among 2720 Norwegian women, ages 40-56 years, who participated in both the Second and Third Tromso studies. Epidemiologic data were obtained through questionnaires. Two questions from the Second Tromso study and five questions from the Third elicited information on physical activity. The mammograms were categorized into five groups based on anatomical-mammographic correlations. For analysis, patterns I through III were combined into a low-risk group and patterns IV and V into a high-risk group. Odds ratios that were adjusted for age, education, menopausal status, body mass index, parity, age at menarche, oral contraceptive use, and alcohol intake, with 95% confidence intervals, were estimated using logistic regression. Women who reported moderate physical activity, i.e., more than 2 h/week, were 20% less likely (odds ratio, 0.8; 95% confidence interval, 0.6-1.1) to have high-risk mammographic patterns compared with those who reported being inactive. This relationship remains consistent when stratified by menopausal status, parity, and tertiles of body mass index. However, all of the associations between various measures of physical activity and high-risk patterns found in this study are weak with confidence intervals that include 1.0. Thus, chance is a reasonable explanation for the weak associations found. The relationship between physical activity and high-risk patterns should be examined further as a means to explore the biologic mechanisms relating physical activity to breast cancer risk. (+info)
Macronutrient intake and change in mammographic density at menopause: results from a randomized trial.
To examine the effects of dietary fat intake on breast cancer risk, we are conducting a randomized trial of dietary intervention in women with extensive areas of radiologically dense breast tissue on mammography, a risk factor for breast cancer. Early results show that after 2 years on a low-fat, high-carbohydrate diet there is a significant reduction in area of density, particularly in women going through menopause. In women who went through menopause during the 2-year follow-up, the mean decreases in area of density and percentage of density in the intervention group were 11.0 cm2 and 11.0%, respectively, whereas the control group decreased 4.5 cm2 and 5.2%. The purpose of this analysis was to determine whether changes in intake of specific macronutrients could account for the observed reduction in breast density in these women. Differences between 2-year and baseline values of macronutrients (averaged over 3 nonconsecutive days of food intake) were calculated. We examined the effect of dietary variables, adjusted for changes in total calorie intake and weight and for family history of breast cancer, on changes in area of density and percentage of density using linear regression. Reduction in total or saturated fat intake or cholesterol intake was significantly associated with decreased dense area (p < or = .004). The most significant dietary variable associated with reduction in percentage of density was reduction in dietary cholesterol intake (P = 0.001), although reducing saturated fat intake was of borderline significance (P = 0.05). The effect of the membership in the intervention and control groups on change in area of density or percentage of density was reduced by models that included changes in intake of any fat, or cholesterol, or carbohydrates. The observation of an effect of diet at menopause on breast density, a marker of increased risk of breast cancer, may be an indication that exposures at this time have an enhanced effect on subsequent risk. (+info)
'Should a mammographic screening programme carry the warning: screening can damage your health!'?
The balanced presentation afforded by convening a Citizens' Jury when considering a major question such as the introduction of a breast screening programme is advocated. This method would enable account to be taken of all the costs, both human and financial, to all those affected, both participating and organizing, as well as the benefits. Provision of such a democratic opportunity enables consideration to be given to a broad range of factors, by selection of an appropriate range of witnesses, with the advantage of involving the lay public in this decision-making process. Attendance by health correspondents, medical journalists and other media representatives enables publicization of a democracy in action whilst helping to inform the wider debate. Such an exercise could inform whether the NHS BSP should continue in its current form. (+info)
American Society of Clinical Oncology 1998 update of recommended breast cancer surveillance guidelines.
OBJECTIVE: To determine an effective, evidence-based, postoperative surveillance strategy for the detection and treatment of recurrent breast cancer. Tests are recommended only if they have an impact on the outcomes specified by American Society of Clinical Oncology (ASCO) for clinical practice guidelines. POTENTIAL INTERVENTION: All tests described in the literature for postoperative monitoring were considered. In addition, the data were critically evaluated to determine the optimal frequency of monitoring. OUTCOME: Outcomes of interest include overall and disease-free survival, quality of life, toxicity reduction, and secondarily cost-effectiveness. EVIDENCE: A search was performed to determine all relevant articles published over the past 20 years on the efficacy of surveillance testing for breast cancer recurrence. These publications comprised both retrospective and prospective studies. VALUES: Levels of evidence and guideline grades were rated by a standard process. More weight was given to studies that tested a hypothesis directly relating testing to one of the primary outcomes in a randomized design. BENEFITS, HARMS, AND COSTS: The possible consequences of false-positive and -negative tests were considered in evaluating a preference for one of two tests providing similar information. Cost alone was not a determining factor. RECOMMENDATIONS: The attached guidelines and text summarize the updated recommendations of the ASCO breast cancer expert panel. Data are sufficient to recommend monthly breast self-examination, annual mammography of the preserved and contralateral breast, and a careful history and physical examination every 3 to 6 months for 3 years, then every 6 to 12 months for 2 years, then annually. Data are not sufficient to recommend routine bone scans, chest radiographs, hematologic blood counts, tumor markers (carcinoembryonic antigen, cancer antigen [CA] 15-5, and CA 27.29), liver ultrasonograms, or computed tomography scans. VALIDATION: The recommendations of the breast cancer expert panel were evaluated and supported by the ASCO Health Services Research Committee reviewers and the ASCO Board of Directors. (+info)
Double-phase 99mTc-sestamibi scintimammography and trans-scan in diagnosing breast cancer.
The goal of our study was to assess the value of both scintimammography with 99mTc-sestamibi (SMM) and trans-scan (T-scan) in detecting breast cancer. METHODS: A total of 121 women were evaluated by palpation, mammography, SMM and T-scan. SMM was performed in the prone, breast dependent position. Immediate and delayed views (double-phase) were obtained. T-scan is a new breast imaging method that maps noninvasively the distribution of tissue electrical impedance and capacitance. RESULTS: SMM had 88.9% sensitivity, 88.4% specificity and 88.4% accuracy in detecting breast cancer. SMM had 100% sensitivity in detecting breast tumors >1 cm and only 66% sensitivity in detecting tumors <1 cm. T-scan had 72.2% sensitivity and 67% specificity in detecting breast cancer. It detected one more breast cancer than SMM, at the expense of 27 additional false-positive results. CONCLUSION: Double-phase SMM was sensitive and specific in detecting breast cancer. This method may reduce the rate of negative breast biopsies in tumors >1 cm. T-scan was only moderately accurate in detecting breast cancer. Its addition to SMM did not improve significantly the rate of breast cancer detection. However, because of its complete noninvasiveness, large-scale applicability and low cost, T-scan deserves further refining. (+info)