Effectiveness of breast-specific gamma imaging (BSGI) for breast cancer in Korea: a comparative study

Despite the fact that mammography has been the golden standard in breast cancer detection for several decades, its sensitivity decreases for women with dense breast tissue, which happens to be common in Korea. As an alternative, breast ultrasonography can be effective diagnostic modalities that complement the defect of mammography. Recently, breast-specific gamma imaging (BSGI) has been introduced as a new diagnostic modality for breast cancer. This study was designed to analyze the effectiveness of BSGI in particular. In a retrospective study, 471 patients underwent BSGI, breast ultrasonography, and mammography simultaneously during the period between February 2009 and March 2010. The indications of BSGI were as follows: (a) patient who was diagnosed with malignancy prior to surgery, (b) patient who is under follow up after cancer surgery, (c) patient with lesions which cannot be evaluated by breast ultrasonography or mammography, (d) patient with multiple benign lesions, and (e) patient with suspicious lesion who refuses biopsy. Among these patients, 121 patients underwent biopsy, whereas others were followed up with imaging studies. We compared the BSGI results with those of mammography, breast ultrasonography, and pathology. The mean age of the patients was 49.63 ± 10.43 years. There were 107 patients with 110 malignant lesions and 364 patients with benign lesions. Total 474 lesions were evaluated. The sensitivities of BSGI, mammography, and breast ultrasonography were 94.45%, 93.64%, and 98.18%, respectively, whereas the specificities of BSGI, mammography, and breast ultrasonography were 90.93%, 90.66%, and 87.09%, respectively. The sensitivity and specificity of BSGI for axillary lymph node (LN) status were 44.7 4% and 87.88%, respectively. BSGI is a good complementary imaging modality with high sensitivity and high specificity for breast cancer detection. However, it has low efficacy for the evaluation for axillary LN status.