Semiquantitative analysis of maximum standardized uptake values of regional lymph nodes in inflammatory breast cancer: is there a reliable threshold for differentiating benign from malignant?
OBJECTIVE
The aim of this study was to determine an optimum standardized uptake value (SUV) threshold for identifying regional nodal metastasis on 18F-fluorodeoxyglucose (FDG) positron emission tomographic (PET)/computed tomographic (CT) studies of patients with inflammatory breast cancer.


METHODS
A database search was performed of patients newly diagnosed with inflammatory breast cancer who underwent 18F-FDG PET/CT imaging at the time of diagnosis at a single institution between January 1, 2001, and September 30, 2009. Three radiologists blinded to the histopathology of the regional lymph nodes retrospectively analyzed all 18F-FDG PET/CT images by measuring the maximum SUV (SUVmax) in visually abnormal nodes. The accuracy of 18F-FDG PET/CT image interpretation was correlated with histopathology when available. Receiver-operating characteristic curve analysis was performed to assess the diagnostic performance of PET/CT imaging. Sensitivity, specificity, positive predictive value, and negative predictive value were calculated using three different SUV cutoff values (2.0, 2.5, and 3.0).


RESULTS
A total of 888 regional nodal basins, including bilateral axillary, infraclavicular, internal mammary, and supraclavicular lymph nodes, were evaluated in 111 patients (mean age, 56 years). Of the 888 nodal basins, 625 (70%) were negative and 263 (30%) were positive for metastasis. Malignant lymph nodes had significantly higher SUVmax than benign lymph nodes (P < .0001). An SUVmax of 2.0 showed the highest overall sensitivity (89%) and specificity (99%) for the diagnosis of malignant disease.


CONCLUSIONS
SUVmax of regional lymph nodes on 18F-FDG PET/CT imaging may help differentiate benign and malignant lymph nodes in patients with inflammatory breast cancer. An SUV cutoff of 2 provided the best accuracy in identifying regional nodal metastasis in this patient population.
Department of Diagnostic Radiology, Unit 1350, The University of Texas MD Anderson Cancer Center, 1515 Holcombe Blvd, Houston, TX 77030, USA. selincarkaci@msn.com
Selin
S
Carkaci
Beatriz E
BE
Adrada
Eric
E
Rohren
Wei
W
Wei
Mohammad A
MA
Quraishi
Osama
O
Mawlawi
Thomas A
TA
Buchholz
Wei
W
Yang
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001943:Breast Neoplasms / Q000000981:diagnostic imaging* / Q000378:metabolism*; D005260:Female; D019788:Fluorodeoxyglucose F18 / Q000493:pharmacokinetics*; D006801:Humans; D008198:Lymph Nodes / Q000000981:diagnostic imaging* / Q000378:metabolism*; D008207:Lymphatic Metastasis; D008297:Male; D008875:Middle Aged; D049268:Positron-Emission Tomography / Q000379:methods / Q000592:standards*; D019275:Radiopharmaceuticals / Q000493:pharmacokinetics; D012016:Reference Values; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity
D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18