Stereotactic core-needle breast biopsy: A multi-institutional prospective trial

PURPOSE: To assess the accuracy of stereotactic core-needle biopsy (CNB) of nonpalpable breast lesions within the context of clinically important para meters of anticipated tissue-sampling error and concordance with mammograph ic findings. MATERIALS AND METHODS: CNB was performed in 1,003 patients, with results va lidated at surgery or clinical and mammographic follow-up. Mammographic fin dings were scored according to the American College of Radiology Breast Ima ging Reporting and Data System with a similar correlative scale for histopa thologic samples obtained at either CNB or surgery. Agreement of CNB findin gs with surgical findings or evidence of no change during clinical and mamm ographic follow-up (median, 24 months) for benign lesions was used to deter mine results. Three forms of diagnostic discrimination measures (strict, wo rking [strict conditioned by tissue sampling error], applied [working condi tioned by concordance of imaging and CNB findings) were used to evaluate th e correlation of CNB, surgical, and follow-up results. RESULTS: Strict, working, and applied sensitivities were 91% +/- 1.9; 92% /- 1.8, and 98% +/- 0.9, respectively; strict, working, and applied specifi cities were 100%, 98% +/- 0.8, and 73% +/- 0.9; strict, working, and applie d accuracies were 97%, 96%, and 79%. CONCLUSION: Percutaneous stereotactic CNB is an accurate method to establis h a histopathologic diagnosis of nonpalpable breast lesions. Accuracy incre ases when additional surgery is performed for lesions with anticipated samp ling error or when CNB findings are discordant with mammographic findings. An understanding of the interrelationship among these parameters is necessa ry to properly assess results.