Mammographic detection of recurrent cancer in the irradiated breast.

Recurrence of cancer in the irradiated breast is an uncommon but potentially curable problem. Posttreatment mammograms were studied in 45 patients who had biopsies of an irradiated breast for suspected local recurrence to evaluate the usefulness of mammography in detecting such recurrences. Of 23 biopsy-proven recurrences, eight (35%) were detected by mammography only, nine (39%) were detected by physical examination only, and six (26%) were detected by both. Mammographic findings in recurrent malignancy included microcalcifications in six, microcalcifications associated with a mass in four, soft-tissue masses in three, and inflammatory changes in one. The results show that mammographic follow-up is complementary to physical examination in the detection of local recurrence in women who have undergone radiation therapy for early breast cancer.

Excretory urography in current practice: evidence against overutilization.

Excretory urography could be performed less frequently if some combinations of genitourinary signs and symptoms were found to be predictive of either a specific disease or normality. To explore this possibility, the authors conducted a prospective study involving more than 3,000 patients at three institutions (a teaching hospital, a community hospital, and a health maintenance organization). Predictive algorithms were obtained by application of a polychotomous logistic regression model but did poorly at differentiating normal from abnormal patients or arriving at a specific diagnosis. Selection of patients on the basis of the logistic model would have required testing 90% of all patients in order to detect 95% of those with abnormal urograms. These results suggest that current clinical selection criteria for excretory urography are effective, and that present frequency of utilization is appropriate.

Selection criteria for upper gastrointestinal examinations: attempts at improvement.

An attempt was made to improve upon selection criteria for the performance of upper gastrointestinal (UGI) series in three settings: a teaching hospital, a community hospital, and a health maintenance organization. Two statistical techniques, the polychotomous logistic model (to develop predictive algorithms for the identification of specific diseases) and the maximum attainable discrimination technique, were used to show the relationship between the percentage of patients with any disease detected and the percentage of UGI examinations performed. Results showed that neither technique improved significantly upon selection criteria for identifying patients with abnormal UGI series.

Selective use of the oblique projection in mammography.

We reviewed the radiographs of patients undergoing negative breast biopsies on the basis of false positive mammograms. In a small number of these patients, the radiologic error was attributable to the summation effect of superimposed focal areas of normal or dysplastic breast tissue giving the false impression of a mass. This summation effect more frequently results in an equivocal radiologic impression, often with a recommendation for short interval repeat mammograms, rather than an actual biopsy. This false positive mammographic appearance can often be suspected on the basis of a discrepancy in the appearance of the suspicious area on the standard lateral and craniocaudad views. In a prospective study we identified women in whom suspicious mammograms were felt to possibly relate to this superimposition effect, and in this small selected group of patients an additional oblique projection was obtained. The oblique view frequently enabled the initially equivocal abnormality to be definitely assessed.

Mammography of the definitively irradiated breast.

The role of mammography in evaluating tumor response was examined in 27 patients undergoing definitive radiation therapy for breast cancer. Radiographic changes observed after treatment included progressive skin thickening, fibrosis of the subcutaneous tissue, and breast retraction. The persistence of a mass more than six months after irradiation suggests treatment failure. Serial mammography may be particularly important in the evaluation of patients with locally advanced disease who require extensive radiation therapy and in whom physical examination is inadequate for the assessment of tumor response.