Breast ultrasonography for detection of metachronous ipsilateral breast tumor recurrence.

BACKGROUND: Early detection of recurrence improves the survival rate of patients treated with breast conservation therapy (BCT). Therefore, ultrasonography (US) may be useful for metachronous ipsilateral breast tumor recurrence (MIBTR) obscured on mammography by dense breast tissue and distortion.

PURPOSE: To evaluate clinical, radiologic, and pathologic findings of MIBTR retrospectively, and to assess the role of surveillance US additional to mammography for MIBTR detection.

MATERIAL AND METHODS: During 2000 to 2012, 28 MIBTR were collected and reviewed among 2958 women treated for primary breast cancer with conservation surgery. The detection rates of imaging studies for identifying metachronous ipsilateral lesions were assessed and compared. MIBTR tumor staging was evaluated according to imaging modality for detection of MIBTR, palpability, and recent imaging surveillance.

RESULTS: No significant difference was observed in the detection rate between mammography and US for overall MIBTR (84.2% vs. 85.7%; P = 0.898) or non-palpable MIBTR (88.2% vs. 81.0%; P = 0.566). US alone identified 33.3% of non-palpable MIBTRs (seven of 21). Among these cases, two had negative mammograms. All 14 MIBTRs with recent imaging surveillance were stage T2 or less, and all seven MIBTRs detected by US alone were in situ or T1; 33% of MIBTRs without recent imaging surveillance were T3 or T4.

CONCLUSION: The overall MIBTR detection rate by US was not higher than the detection rate of mammography, although combined surveillance with US and mammography found MIBTRs slightly earlier than mammography alone.