Breast scintigraphy as a surrogate method for differentiation of unclear mammographic findings

Background: Mammography is the gold standard of breast diagnostics. Complet ely new radiological developments are not to be expected in the near future . Thus, additive methods for mammography such as sonography, Doppler sonogr aphy, MRI, and scintigraphy are being increasingly employed. In this study, the mammography findings were compared with breast scintigraphy to define the limitations of both methods. The goal of the employing additional diagn ostical methods besides mammography is to reduce the number of "open" biops ies. Patients and Methods: The histological findings of 1206 breast operations ( in 1035 women) were analysed retrospectively. The indication to operate was based on a pathological mammographic or clinical finding. One hundred and forty patients with unclear mammographic findings were subjected to additio nal breast scintigraphy with (99m)Technetium prior to the planned operation s. Results: In 619 operations, a malignant diagnosis was obtained (51.3%); the other 587 operations resulted in benign findings (48.7%). This is about a 1:1 ratio of benign to malignant final diagnosis from the operative breast biopsy. Histological benign findings included 242 (41.2%) fibrotic-cystic m astopathies and 168 (28.8%) fibroadenomas. These findings had been detected by mammography or clinical examination, but could not be clearly defined a s benign and thus resulted in the necessity to operate. The additive implem entation of breast scintigraphy resulted in a pre-operative diagnosis of 32 of 34 histologically confirmed mastopathic findings. The additive scintigr aphy also resulted in a pre-operative diagnosis of 8 of 11 histologically c onfirmed fibroadenomas. The results of the breast scintigraphy thus had a h igher specificity of 86% compared to normal mammography (specificity 47.9%) ; the sensitivity, however, was lower (79%) than that of mammography (90%). The results of breast scintigraphy for therapy monitoring of women with in flammatory breast cancer who received primary chemotherapeutic treatment co rrelated well with the clinical signs of remission and histological finding s. Mammography and MRI failed to be of use in these cases. Conclusions: The enthusiastic reports from the USA concerning breast scinti graphy e.g. including suggestions on its implementation as a diagnostic met hod alone without mammography, cannot be confirmed as yet by German studies . Scintigraphy is still too new compared to the well-established mammograph y, so that experience an using this method must still be gained. However, b reast scintigraphy is a useful complementary method for interdisciplinary b reast diagnostics and may lead to a reduction of the necessity for "open" b iopsies.