Contrast-enhanced CT: value for diagnosing local breast cancer recurrence after conservative treatment.

PURPOSE: To assess contrast material-enhanced computed tomography (CT) of breast for diagnosing local recurrence after conservative therapy. MATERIALS AND METHODS: In 111 patients, 118 lesions were evaluated with unenhanced and enhanced CT. Criterion for cancer recurrence was detection of a lesion with an enhancement of 45 HU or more. RESULTS: One group comprised 52 lesions with pathologic diagnoses, obtained within 1 month of CT, of malignancy in 43 and benignancy in nine. Scans were positive in 40 of 43 recurrences and negative in six of nine benign lesions. Seventeen recurrent lesions were nonpalpable, and contrast-enhanced CT results were true-positive in 15 of these. A second group comprised 66 lesions with a mean follow-up of the treated breast of 28 months after CT. In 56 lesions, the scans were negative, with no recurrence in 55; local recurrence was proved with a 14-month delayed surgical biopsy in one. In 10 lesions, scans were positive, with a delayed diagnosis of recurrence 5 and 6 months after CT in two and no evidence of recurrence in eight (false-positive results). The sensitivity of breast CT for both groups was 91% (42 of 46 lesions) with a specificity of 85% (61 of 72 lesions). CONCLUSION: Contrast-enhanced CT is sensitive in the diagnosis of local recurrence of breast cancer, even in nonpalpable lesions, and may be a useful tool in patients with equivocal clinical and/or mammographic findings during follow-up after conservative therapy.