despite medicare approving the use of positron emission tomography / computed tomography ( pet / ct ) in staging primary breast cancer , little evidence is available to support the use of f - fdg - pet / ct for the detection of distant metastases in the initial staging of breast cancer . the national comprehensive cancer network recommends the following types of imaging for staging locally advanced breast cancer at the time of clinical diagnosis : bilateral mammography , breast ultrasonography as necessary , and chest imaging if patients had no symptoms or other abnormal staging studies , and breast magnetic resonance imaging ( mri ) , skeletal scintigraphy ( ss ) , and abdominal and/or pelvic computed tomography ( ct ) , ultrasonography , or mri if patients had symptoms or other abnormal staging studies.1 breast cancer patients with large tumors ( stage t3 or greater ) have an 8.3% to 15.1% risk of distant metastases.2 - 4 because locally advanced breast cancer has a very high rate of relapse,5 it is possible that the conventional imaging modalities noted above may fail to detect a substantial number of metastases.6 in this review , we examine whether f - fdg - pet / ct may play a role in the initial staging of breast cancer . many practicing investigators speculate that pet / ct might be more accurate than conventional imaging techniques for detecting distant metastases ; table 1 summarizes studies that have addressed this issue . fuster et al . , in a study of 60 primary breast cancer patients with large tumors , reported that 5 of the 8 cases of distant metastatic lesions were unsuspected before pet / ct was performed.7 carkaci et al . reported that among 41 patients with inflammatory breast cancer , 7 of the 20 cases of distant metastases were unsuspected before pet / ct examination.8 alberini et al . reported that among 62 patients with inflammatory breast cancer , 6 of 18 cases of distant metastases were unsuspected before pet / ct was performed.9 heusner et al . reported that among 40 patients with breast cancer , 3 of 10 cases of distant metastases were unsuspected before pet / ct was performed.10 groheux et al . reported that among 39 patients with clinical stage ii and iii breast cancer , all 4 cases of distant metastases were unsuspected before pet / ct was performed.11 on the basis of their results , both carkaci et al . and alberini et al . recommended the use of pet / ct in the initial staging of inflammatory breast cancer.8,9 in summary , although pet / ct has an estimated specificity and sensitivity of 95% and 99% , not enough data are available to recommend the routine use of pet / ct in breast cancer staging because the studies mentioned above all had small numbers of patients . further , the ability of pet / ct to detect distant metastases has never been tested prospectively in a large group of patients . another possible role of pet / ct may be its use in detecting local lymph node metastases from breast cancer . pet / ct provides more detailed anatomical information than pet alone about axillary and extra - axillary lymph nodes.78 fuster et al . reported that pet / ct was able to reveal previously unsuspected infiltration of axillary lymph nodes in 10 of 60 patients and infiltration of extra - axillary lymph nodes in 3 of 60 patients.7 carkaci et al . reported that among 41 inflammatory breast cancer patients , pet / ct detected metastases in the axillary lymph nodes of 37 ( 90% ) , subpectoral lymph nodes of 19 ( 46% ) , supraclavicular lymph nodes of 10 ( 24% ) , and internal mammary lymph nodes of 9 ( 22%).8 in the same study , 6 false - negative findings did not show hypermetabolism on pet / ct but showed malignancy on sonography - guided fine - needle aspiration biopsy . ueda et al . reported that the diagnostic sensitivity and specificity of f - fdg - pet / ct were nearly equal to those of ultrasonography , 58% and 95% , respectively , compared with 54% and 99% in ultrasonography.12 although the studies listed above reported some false - positive findings in both the lymph nodes and distant sites,7,8 pet / ct resulted in fewer false - positive findings than did pet alone.7,8 however , not every distant metastatic site detected by pet / ct was confirmed by histopathological analysis in these studies . diagnostic biopsy of the metastatic site is the gold standard for diagnosing metastatic lesions , and if pet / ct reveals suspected distant metastases , a biopsy must be performed to confirm those findings . in summary , the use of pet / ct in the initial staging of primary breast cancer is not yet well defined and not recommended at present because there is limited evidence to support its use . however , because studies have shown that pet / ct may enable accurate detection of local lymph node metastases and distant metastases , pet / ct offers another option for use in primary breast cancer staging . for cases in which conventional imaging techniques ( i.e. ultrasonography , ct , mri , ss ) do not provide adequate information , pet / ct could be used to obtain more detailed anatomical information .
despite medicare approving the use of positron emission tomography / computed tomography ( pet / ct ) in staging primary breast cancer , little evidence is available to support the use of 18f - fdg - pet / ct for the detection of distant metastases in the initial staging of breast cancer . in this review of the literature listed in medline 
 , we examine whether 18f - fdg - pet / ct may play a role in the initial staging of breast cancer . 
 we discuss studies comparing pet / ct with conventional imaging for diagnosing distant metastases and axillary and extra - axillary lymph node metastases .