B r e a s t T u m o rs: C o m p a ra tiv e A c c u ra c y o f MR Im a g in g R elativ e to M a m m o g ra p h y a n d US fo r D e m o n s tra tin g E x te n t1 A PURPOSE; To evaluate the compara tive accuracy of magnetic resonance (MR) imaging relative to mammogra phy and ultrasonography (US) for assessing the extent of breast tumors. MATERIALS A N D METHODS:His tologic results and preoperative im aging findings (mammography, US, MR imaging) were analyzed regard ing tumor size and multifocality of 61 tumors in 60 women undergoing mastectomy for carcinoma. RESULTS:In 10% of cases, the index tumor was not seen at mammogra phy. With US, 15% of the index tu mors were not recognized, while MR imaging missed 2% of the index tu mors. On mammographic and US images, tumor size was underesti mated significantly (P < .005), by 14% and 18%, respectively, while MR im aging showed no significant differ ence in size compared with that found in a pathologic evaluation. Mammography showed 31% of the additional invasive lesions, w hile US showed 38% and MR imaging showed 100%. CONCLUSION: MR imaging was the most accurate of the three preopera tive imaging modalities in assessing the size and number of malignant lesions in the breast.

Gadolinium-enhanced TurboFLASH imaging is a valuable method in the examination of breast lesions suspected of being malignant.

MRI was more accurate than mammography in annual breast cancer surveillance of women with a hereditary risk of breast cancer. Larger prospective studies to examine the role of MRI in screening programs are justified.

Mammographic screening for women aged 50-70 is effective in reducing breast cancer mortality, but the impact on quality of life and the attainable mortality reduction remain to be discussed. The consequences of expanding screening programmes to include women in other age groups are uncertain. We have predicted the effects and costs for 5 popular screening variants, differing in age group and screening interval, on the basis of our analysis of the Dutch screening trials and of the reported mortality reductions in other trials. We have also investigated the influence of a large number of uncertain factors. Screening for women aged 50 and over with a 2- or 3-year interval is very cost-effective and will result in reductions of respectively 16% or 10% in breast cancer mortality in a real population. Variation of most variables keeps the cost-effectiveness (CE) ratio limited to the range of US $3,000 to 5,000 per life-year gained. A 2- to 3-fold change in CE ratio would only occur if the extreme estimates of mortality reduction in the Swedish screening trials were applied. The impact on quality of life (QoL) is limited: for the 2-yearly screening policy for women aged 50-70, the cost per Quality-Adjusted Life-Year (QALY) gained is 4,050, whereas the cost per life-year gained is US $3,825. The CE ratio for 2-yearly screening of women aged 40-70 is 5,400, but the additional cost per additional life-year gained is US $35,000. It would be preferable by far to extend the screening programme to women over the age of 70 or to shorten the screening interval for women aged 50-70. Screening performances, the demand for mammograms outside screening and the possibility of a survival improvement irrespective of screening have a strong impact on QoL and CE.