Abstract P4-01-02: Diagnostic value of breast specific gamma imaging for breast cancer
Authors: Mallik DK , Zhang H , Shi H , Tan H , Shen L , Hu G , Hu H , Sejdinaj F , Pang Y , Zhu W , Yang W 
Published: March 2017

In this study, 422 female patients who presented with clinical indications and underwent ultrasound (US), mammography (MMG), and breast specific gamma imaging (BSGI) before surgery during the period from July 2013 to June 2015 were retrospectively reviewed. Twenty-two of the patients had no pathological report available and were excluded. These patients who presented with clinical indications underwent both ultrasound and mammographic examinations initially. If both US and MMG were positive, the patient was recommended for a BSGI examination for pre-surgical planning. A BSGI examination was also recommended for patients with negative or indeterminate mammographic findings.

The diagnostic results were compared with histological examination and the sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) for each modality were determined. Combinations of either two or three of the diagnostic results were also reviewed and the corresponding diagnostic indicators calculated. For these combinations, a positive indication on one of the two (or three) diagnostic tests were interpreted as a positive result. The sensitivity of US, MMG, BSGI, the combination of US and MMG, US and BSGI, MMG and BSGI, and the combination of all three together in the diagnosis of breast carcinoma were determined for the 400 patients included in the study and are listed in Table 1, column 1. The specificity, PPV, and NPV for each of these modalities and combinations of modalities were also determined and are shown Table 1, column 2-4.

Table 1 SensitivitySpecificityPPVNPVUS61.389.289.759.8MMG67.594.394.765.2BSGI83.187.991.477.1US & MMG86.884.789.880.6US & BSGI91.382.889.186.1MMG & BSGI92.283.489.585.6US & MMG & BSGI97.579.087.895.4

The population was comprised of 243 patients with 245 malignant lesions and 157 patients with 189 benign lesions. The malignant lesions were primarily infiltrating ductal carcinoma (76%) and ductal carcinoma in situ (14%), with the remaining lesions (10%) being invasive lobular carcinoma, Paget's disease and mixed carcinomas. The benign lesions were primarily fibroadenoma (39%), adenosis (40%) and papilloma (10%), with the remaining lesions (11%) being duct ectasia, inflammation or phyllodes. There were 79 false negative cases by MMG, however, when ultrasound and BSGI were combined, 73 out of 79 were accurately identified. Additionally, there were nine, seventeen and eighteen Ductal Carcinoma in situ (DCIS) misdiagnosed by BSGI, MMG, and ultrasound respectively, but through joint imaging of BSGI+MMG+US; 33 out of 35 were accurately judged.

BSGI is a useful adjunct modality for the diagnosis of breast carcinoma. It is also extremely useful for diagnosis of non-calcified DCIS, and circumvents limitations of mammography in identifying malignant lesion in dense breast. Moreover, it is helpful for improving the diagnosis accuracy of breast carcinoma when BSGI is combined together with MMG and US.

Citation Format: Mallik DK, Zhang H, Shi H, Tan H, Shen L, Hu G, Hu H, Sejdinaj F, Pang Y, Zhu W, Yang W. Diagnostic value of breast specific gamma imaging for breast cancer [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr P4-01-02.