Scintimammography enhances negative predictive value of non-invasive pre-operative assessment of breast lesions

Aims: The aim of this study was to develop a criterion with a high negative predictive value for the evaluation of breast lesions. We aimed to determi ne the value of combining three non-invasive tests, mammography (MM), ultra sonography (USS) and 99mTc-methoxyisobutylisonitrite (99mTc-MIBI) scintimam mography (scinti-MM). Methods: We included 94 consecutive patients with suspected lesions detecte d by mammography or on physical examination. MM, USS and scinti-MM were per formed no more than 4 weeks prior to excisional biopsy in all patients. We then compared the biopsy results with a score calculated for each patient, derived from the results of the three tests, which we termed 'mamma maligna ncy index' (MMI). Results: Each of the three exams yielded a score ranging from 0 to 2, with 0 representing ay almost certainly benign lesion, 1 an indeterminate findin g and 2 a likely malignant lesion, and hence giving a total score ranging f rom 0 to 6. The biopsy results showed that the lesions in 64 patients were benign. Forty-nine (77%) of these patients had received an MMI score of 0 o r 1. The negative predictive value for malignancy in patients with a score less than 2 was 100%. Conclusions: Since the smallest detected lesion was 9 mm in diameter, we co nclude that MMI may be a highly useful diagnostic tool in the delineation o f breast lesions greater than or equal to 1 cm which should not be routinel y referred for biopsy but may be followed non-invasively. Although fine nee dle aspiration has limitations, we would recommend it as a less invasive me thod to evaluate suspected lesions smaller than 1 cm. (C) 2000 Harcourt Pub lishers Ltd.