ABSTRACT
The purpose of mammographic screening is to improve patient survival by detecting cancer at an earlier, more curable stage than is possible with physical examination. Three major studies have been used to assess the effect of mass screening on the survival rates and mortality for patients with breast cancer: the Breast Cancer Detection Demonstration Project, the Health Insurance Plan study, and the study conducted by the Swedish National Board of Health and Welfare. The author reviews these studies, describes statistical biases (lead time, length time, patient self-selection, and overdiagnosis) to be considered in study design and analysis, and discusses briefly risks versus benefits of mammography.
Subject(s)
Mammography , Bias , Breast Neoplasms/diagnostic imaging , Breast Neoplasms/epidemiology , Breast Neoplasms/mortality , Female , Humans , Mammography/adverse effects , Research , Risk FactorsABSTRACT
Detectability of breast cancer with magnetic resonance (MR) imaging versus xeromammography was quantitatively compared. MR images were obtained of breasts of 120 women who underwent xeromammography. T1 values were determined for masses larger than 2 cm. Cancer was histologically confirmed in 39 breasts and was considered excluded from 81 due to results of biopsy, cyst aspiration, or sonography or absence of change in xeromammographic findings over time. Images were blindly interpreted by three observers, and results were expressed as receiver operating characteristic curves. Detectability of breast cancer was substantially better with xeromammography than with MR imaging for all observers (P less than .03, 10(-6), and .001). On MR images, spiculation of a mass, distorted architecture, skin thickening, and nipple or skin retraction were specific but relatively insensitive indicators of cancer. Masses with smooth, distinct margins and signal intensity greater than that of fat on T2-weighted images were always benign. Other findings and T1 values were not diagnostically useful. The authors conclude that xeromammography is superior to MR imaging in detection of breast cancer.
Subject(s)
Breast Neoplasms/diagnosis , Magnetic Resonance Imaging , Mammography , Xeromammography , Breast Diseases/diagnosis , Breast Diseases/diagnostic imaging , Breast Neoplasms/diagnostic imaging , Female , Humans , Middle Aged , ROC Curve , Sensitivity and SpecificityABSTRACT
We believe that the preponderance of evidence suggests that MRI is less accurate than conventional mammography in the diagnosis of primary cancer of the breast. Thus, it currently has no established place in algorithms for the evaluation of patients suspected of having breast cancer. MRI could be used to evaluate masses with mammographically smooth, well-defined margins, since high signal intensity (greater than fat) in a T2-weighted image is a highly specific indicator of benignancy in such lesions. However, most of these masses are cysts and can be reliably and less expensively identified as such by sonography. Nonetheless, MRI might be used to re-evaluate a smooth, well-defined mass if sonography has failed to identify the lesion as a cyst. MRI might be particularly useful in this regard if a lesion is difficult to evaluate by other modalities because it is located adjacent to the chest wall, is deep within a very large breast, or is obscured by a breast prosthesis. MRI with Gd-DTPA may be useful in evaluating radiographically dense breasts or in differentiating breast malignancies from irregular dysplastic or scar tissue. However, further investigation of this technique is needed. It has been hoped that in vivo measurement of T1 and T2 or in vivo NMR spectroscopy might improve the accuracy of noninvasive diagnosis of cancer of the breast. However, there is currently no credible evidence that in vivo measurements of relaxation times provide useful indexes for the diagnosis of breast cancer. In vivo NMR spectroscopy of nuclei other than P may ultimately provide reliable criteria for noninvasive diagnosis of breast cancer in humans, but the technique is currently in its infancy.
Subject(s)
Breast Neoplasms/diagnosis , Magnetic Resonance Imaging/methods , Contrast Media , Female , Gadolinium , Gadolinium DTPA , Humans , Magnetic Resonance Spectroscopy , Organometallic Compounds , Pentetic AcidSubject(s)
Breast Neoplasms/diagnostic imaging , Computers , Mammography/methods , Xeromammography/methods , Breast/anatomy & histology , Female , Humans , RiskABSTRACT
Pretreatment staging is considered essential in the management of patients with malignant lymphoma, particularly nodular sclerosing Hodgkin disease. The results of CT examination of 33 patients with malignant lymphoma are correlated with the results of lymphangiography, nuclide images of the liver and spleen, gallium citrate57 images of lymphoid tissue, and nuclide bone images. CT is least effective in the early clinical stages of malignant lymphoma because normal or minimally enlarged nodes are difficult to detect; CT is probably reliable enough to replace lymphangiography of gallium57 imaging in patients with advanced disease.
