Diagnostic value of diffusion-weighted magnetic resonance imaging (DWI) compared to FDG PET/CT for whole-body breast cancer staging.
OBJECTIVE
The aim of the study was to prospectively compare the diagnostic value of whole-body diffusion-weighted imaging (DWI) and FDG PET/CT for breast cancer (BC) staging.


METHODS
Twenty BC patients underwent whole-body FDG PET/CT and 1.5-T DWI. Lesions with qualitatively elevated signal intensity on DW images (b = 800 s/mm(2)) were rated as suspicious for tumour and mapped to individual lesions and different compartments (overall 552 lesions). The apparent diffusion coefficient (ADC) value was determined for quantitative evaluation. Histopathology, MRI findings, bone scan findings, concordant findings between FDG PET/CT and DWI, CT follow-up scans and plausibility served as the standards of reference defining malignancy.


RESULTS
According to the standards of reference, breasts harboured malignancy in 11, regional lymph nodes in 4, M1 lymph nodes in 3, bone in 7, lung in 2, liver in 3 and other tissues in 3 patients. On a compartment basis, the sensitivity, specificity, accuracy, positive predictive value (PPV) and negative predictive value (NPV) for the detection of malignancies were 94, 99, 98, 97 and 98% for FDG PET/CT and 91, 72, 76, 50 and 96% for DWI, respectively. Of the lesions seen on DWI only, 348 (82%) turned out to be false-positive compared to 23 (11%) on FDG PET/CT. The average lesion ADC was 820 +/- 300 with true-positive lesions having 929 +/- 252 vs 713 +/- 305 in false-positive lesions (p < 0.0001).


CONCLUSIONS
Based on these initial data DWI seems to be a sensitive but unspecific modality for the detection of locoregional or metastatic BC disease. There was no possibility to quantitatively distinguish lesions using ADC. DWI alone may not be recommended as a whole-body staging alternative to FDG PET(/CT). Further studies are necessary addressing the question of whether full-body MRI including DWI may become an alternative to FDG PET/CT for whole-body breast cancer staging.
Heusner
Till-Alexander
TA
Department of Diagnostic and Interventional Radiology and Neuroradiology, University Hospital Essen, University of Duisburg-Essen, Hufelandstrasse 55, 45122, Essen, Germany. till.heusner@uni-due.de
Kuemmel
Sherko
S
Koeninger
Angela
A
Hamami
Monia E
ME
Hahn
Steffen
S
Quinsten
Anton
A
Bockisch
Andreas
A
Forsting
Michael
M
Lauenstein
Thomas
T
Antoch
Gerald
G
Stahl
Alexander
A
D000328:Adult; D000368:Aged; D001943:Breast Neoplasms / Q000175:diagnosis* / Q000000981:diagnostic imaging / Q000473:pathology*; D004058:Diffusion; D019788:Fluorodeoxyglucose F18; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods* / Q000592:standards; D008875:Middle Aged; D009362:Neoplasm Metastasis; D009367:Neoplasm Staging; D049268:Positron-Emission Tomography / Q000379:methods* / Q000592:standards; D011446:Prospective Studies; D012015:Reference Standards; D014057:Tomography, X-Ray Computed / Q000379:methods* / Q000592:standards; D051598:Whole Body Imaging
D019788:Fluorodeoxyglucose F18