This is important because patients with locoregional breast malignancy have 5-year survival rates of 76% to 99%, but for patients with distant metastases, 5-year survival rates decreases to 20% to 28% [159]. The sensitivity, specificity, PPV, NPV, and accuracy of PET/CT in identifying metastatic disease in this population are 100%, 96%, 80%, 100%, and 97%, respectively [41]. The false-positive rate of PET/CT was 19%. In comparison with CT and other modalities, 80% of patients with distant disease had the metastases exclusively identified on PET/CT [41]. Groheux et al [136] investigated 254 patients and found previously unknown metastases in 1 of 44 (2%) women with stage IIA breast cancer, 6 of 56 (11%) women with stage IIB cancer, 11 of 63 (18%) women with stage IIIA cancer, 27 of 74 (37%) women with stage IIIB cancer, and 8 of 17 (47%) women with stage IIIC cancer. PET/CT has especially high yields in the case of patients newly diagnosed at <40 years of age, revealing distant metastases in 17% of asymptomatic patients with stage IIB breast cancer <40 years of age [155]. PET/CT modified staging between 14% and 28% of patients with late-stage disease, regardless of tumor receptor status [138,139]. In a study of 163 women, PET/CT and whole body bone scan demonstrated concordance in identifying osseous metastases in 81% of cases. Also, PET/CT had the added benefit of detecting extraosseous metastasis in 62% of patients with osseous metastasis. Of those patients with extraosseous metastases, 6% had equivocal and 42% had negative bone scans [160]. The sensitivity and specificity for PET/CT in the detection of distant metastases is higher than conventional imaging, with a 97% sensitivity and 91% specificity versus an 86% sensitivity and 67% specificity, respectively (P = . 009 and P < . 001, respectively) [161]. However, PET/CT has limited sensitivity for ILC [162].
Imaging of Invasive Breast Cancer. This is important because patients with locoregional breast malignancy have 5-year survival rates of 76% to 99%, but for patients with distant metastases, 5-year survival rates decreases to 20% to 28% [159]. The sensitivity, specificity, PPV, NPV, and accuracy of PET/CT in identifying metastatic disease in this population are 100%, 96%, 80%, 100%, and 97%, respectively [41]. The false-positive rate of PET/CT was 19%. In comparison with CT and other modalities, 80% of patients with distant disease had the metastases exclusively identified on PET/CT [41]. Groheux et al [136] investigated 254 patients and found previously unknown metastases in 1 of 44 (2%) women with stage IIA breast cancer, 6 of 56 (11%) women with stage IIB cancer, 11 of 63 (18%) women with stage IIIA cancer, 27 of 74 (37%) women with stage IIIB cancer, and 8 of 17 (47%) women with stage IIIC cancer. PET/CT has especially high yields in the case of patients newly diagnosed at <40 years of age, revealing distant metastases in 17% of asymptomatic patients with stage IIB breast cancer <40 years of age [155]. PET/CT modified staging between 14% and 28% of patients with late-stage disease, regardless of tumor receptor status [138,139]. In a study of 163 women, PET/CT and whole body bone scan demonstrated concordance in identifying osseous metastases in 81% of cases. Also, PET/CT had the added benefit of detecting extraosseous metastasis in 62% of patients with osseous metastasis. Of those patients with extraosseous metastases, 6% had equivocal and 42% had negative bone scans [160]. The sensitivity and specificity for PET/CT in the detection of distant metastases is higher than conventional imaging, with a 97% sensitivity and 91% specificity versus an 86% sensitivity and 67% specificity, respectively (P = . 009 and P < . 001, respectively) [161]. However, PET/CT has limited sensitivity for ILC [162].