Radiology 2003 Jan;226(1):181-7
Screening for Cerebral Metastases with FDG PET in Patients Undergoing
Whole-Body Staging of Non-Central Nervous System Malignancy.
Rohren EM, Provenzale JM, Barboriak DP, Coleman RE.
PURPOSE: To compare fluorine 18 fluorodeoxyglucose (FDG) positron emission
tomography (PET) with the current standard, magnetic resonance (MR) imaging, to
determine the sensitivity and specificity of FDG PET for detection of cerebral
metastases and to determine the factors that may affect lesion conspicuity.
MATERIALS AND METHODS: Forty patients underwent brain PET and contrast
material-enhanced brain MR imaging, with a maximum of 30 days between
examinations. PET and MR images were each retrospectively reviewed by two
independent readers who were blinded to the clinical history and results of the
other technique. Presence of metastatic disease was recorded for each modality.
Sensitivity and specificity of FDG PET were determined with MR imaging as the
standard. Statistical analysis was performed with the Fisher exact test and the
logistic regression model. RESULTS: Sixteen patients had cerebral metastases at
MR imaging, and in 12 of these, PET scans were interpreted as showing metastatic
disease (in four, scans were false-negative). Twenty-four patients had no
cerebral metastases at MR imaging, and 20 of these had PET scans interpreted as
normal (in four, scans were false-positive). For identification of patients with
cerebral metastases, FDG PET had a sensitivity of 75% (12 of 16) and a
specificity of 83% (20 of 24). Thirty-eight metastatic lesions were seen at MR
imaging; 23 (61%) of these were identified at PET. Size was a statistically
significant factor that influenced lesion detection at PET (P <.001).
CONCLUSION: Only 61% of metastatic lesions in the brain were identified at PET.
In particular, detection of small lesions was difficult. Copyright RSNA, 2002
