18fluorodeoxyglucose positron emission tomography to detect mediastinal or internal mammary metastases in breast cancer.
OBJECTIVE
To determine the prevalence of suspected disease in the mediastinum and internal mammary (IM) node chain by 18fluorodeoxyglucose (FDG) positron emission tomography (PET), compared with conventional staging by computed tomography (CT) in patients with recurrent or metastatic breast cancer.


METHODS
We retrospectively evaluated intrathoracic lymph nodes using FDG PET and CT data in 73 consecutive patients with recurrent or metastatic breast cancer who had both CT and FDG PET within 30 days of each other. In reviews of CT scans, mediastinal nodes measuring 1 cm or greater in the short axis were considered positive. PET was considered positive when there were one or more mediastinal foci of FDG uptake greater than the mediastinal blood pool.


RESULTS
Overall, 40% of patients had abnormal mediastinal or IM FDG uptake consistent with metastases, compared with 23% of patients who had suspiciously enlarged mediastinal or IM nodes by CT. Both FDG PET and CT were positive in 22%. In the subset of 33 patients with assessable follow-up by CT or biopsy, the sensitivity, specificity, and accuracy for nodal disease was 85%, 90%, and 88%, respectively, by FDG PET; 54%, 85%, and 73%, respectively, by prospective interpretation of CT; and 50%, 83%, and 70%, respectively, by blinded observer interpretation of CT. Among patients suspected of having only locoregional disease recurrence (n = 33), 10 had unsuspected mediastinal or IM disease by FDG PET.


CONCLUSIONS
FDG PET may uncover disease in these nodal regions not recognized by conventional staging methods. Future prospective studies using histopathology for confirmation are needed to validate the preliminary findings of this retrospective study.
Eubank
W B
WB
Department of Radiology, University of Washington School of Medicine, Seattle, USA. weubank@u.washington.edu
Mankoff
D A
DA
Takasugi
J
J
Vesselle
H
H
Eary
J F
JF
Shanley
T J
TJ
Gralow
J R
JR
Charlop
A
A
Ellis
G K
GK
Lindsley
K L
KL
Austin-Seymour
M M
MM
Funkhouser
C P
CP
Livingston
R B
RB
D000328:Adult; D000368:Aged; D001706:Biopsy; D001943:Breast Neoplasms / Q000000981:diagnostic imaging* / Q000378:metabolism / Q000473:pathology; D018567:Breast Neoplasms, Male / Q000000981:diagnostic imaging / Q000378:metabolism / Q000473:pathology; D005260:Female; D019788:Fluorodeoxyglucose F18 / Q000493:pharmacokinetics; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008207:Lymphatic Metastasis; D008297:Male; D008479:Mediastinal Neoplasms / Q000000981:diagnostic imaging / Q000378:metabolism / Q000556:secondary*; D008875:Middle Aged; D009367:Neoplasm Staging; D015995:Prevalence; D011446:Prospective Studies; D019275:Radiopharmaceuticals / Q000493:pharmacokinetics; D012189:Retrospective Studies; D012680:Sensitivity and Specificity; D014055:Tomography, Emission-Computed; D014057:Tomography, X-Ray Computed
D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18