Prospective evaluation of CECT and 18F-FDG-PET/CT in detection of hepatic metastases.
OBJECTIVE
The purpose of this study was to evaluate the performance of F-fluorodeoxy-D-glucose (FDG)-PET/computed tomography (CT) and contrast-enhanced CT (CECT) in the detection and characterization of hepatic metastases.


METHODS
Forty-five patients harboring an extrahepatic primary malignancy, with suspected hepatic metastases on clinical or ultrasonographic examination were enroled prospectively. Each patient underwent contrast-enhanced abdominal CT and F-FDG-PET/CT within 72 h of each other, reported by an experienced radiologist and nuclear medicine specialist, respectively in a blinded manner. CECT and PET-CT findings were compared and analyzed. Final diagnosis was based on histology and/or follow-up (ranging from 6 to 12 months).


RESULTS
The sensitivity and specificity of CECT in the detection of hepatic metastases was 87.9 and 16.7%, respectively, whereas that of PET/CT was 97 and 75%, respectively. This study showed the superiority of PET/CT over CECT in the detection of hepatic metastases, irrespective of the primary site. This was especially owing to the latter's inability to reliably distinguish small (less than 15 mm) lesions as benign or malignant.


CONCLUSIONS
Many studies have been conducted on the impact of FDG-PET/CT in the evaluation of hepatic metastases, especially from colorectal primary. Very few prospective studies, however, have been conducted on its role in evaluation of hepatic metastases from nongastrointestinal primaries. Despite its superior performance, it cannot replace CECT for this purpose, owing to the low but definite risk of false positivity based on PET-CT findings alone. Inclusion of CECT in PET/CT protocols may enable us to achieve a higher diagnostic accuracy. This suggests the need for a large prospective study with serial evaluations and pathological correlation.
D'souza
Maria Mathew
MM
Department of PET Imaging, Institute of Nuclear Medicine and Allied Sciences, Delhi, India. maria.md@rediffmail.com
Sharma
Rajnish
R
Mondal
Anupam
A
Jaimini
Abhinav
A
Tripathi
Madhavi
M
Saw
Sanjiv Kumar
SK
Singh
Dinesh
D
Mishra
Anil
A
Tripathi
Rajendra Prasad
RP
D000293:Adolescent; D000328:Adult; D000368:Aged; D003287:Contrast Media; D005260:Female; D019788:Fluorodeoxyglucose F18; D006801:Humans; D008113:Liver Neoplasms / Q000175:diagnosis* / Q000556:secondary*; D008297:Male; D008875:Middle Aged; D049268:Positron-Emission Tomography / Q000379:methods*; D011446:Prospective Studies; D011860:Radiography, Abdominal / Q000379:methods*; D019275:Radiopharmaceuticals; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013382:Subtraction Technique; D014057:Tomography, X-Ray Computed / Q000379:methods*; D055815:Young Adult
D003287:Contrast Media; D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18