Is combined 18F-fluorodeoxyglucose-positron emission tomography/computed tomography superior to positron emission tomography or computed tomography alone for diagnosis, staging and restaging of pancreatic lesions?
OBJECTIVE
To evaluate whether combined 18F-FDG PET/CT has an additive value over 18F-FDG-PET or CT alone for diagnosis, staging and restaging of pancreatic lesions.


METHODS
Forty-six consecutive patients (23 women, 23 men; median age 62.5 years) underwent FDG-PET/CT. Analysis of PET, CT and fused PET/CT images was performed by 2 readers. Patients were divided into 2 groups: diagnosis and staging of primary tumours (n=34) and restaging: screening for recurrent or progressive pancreatic cancer (n=12). Accuracy analysis was performed lesion-by-lesion and patient-by-patient. Results were correlated with histopathology or clinical follow-up.


RESULTS
Ninety-five foci were identified on PET, 140 lesions on CT and 119 on PET/CT. Thirty-four lesions were defined as 'definitely pathologic' and localised in pancreas, liver, lung or bone by all 3 techniques with equal certainty. In 11 patients malignancy was ruled out with the highest certainty by PET/CT. All 3 modalities made 2 false positive diagnoses of malignancy and missed metastases or vascular ingrowth in 7 patients. The accuracy rate of PET/CT (91.2%) for diagnosis of primary pancreatic lesions is higher compared to CT (88.2%) and PET alone (82.3%). Also for locoregional staging PET/CT has a higher accuracy rate (85.3%) compared to CT (83.8%) and PET (79.4%). When used for restaging, sensitivity (90.0%) and accuracy rate (91.6%) were highest for PET and PET/CT. CT had a lower sensitivity (80.0%).


CONCLUSIONS
Topographical assignment of 'spots' with high FDG uptake is superior with PET/CT compared to PET alone. Fused PET/CT has a slightly higher sensitivity and accuracy rate for diagnosis and locoregional staging of primary pancreatic lesions compared to CT alone. PET and PET/CT perform equally well in screening for recurrent or progressive pancreatic cancer, with high accuracy. Due to its unlimited access, lower radiation exposure and cost, multidetector row CT remains the imaging technique of choice for diagnosis, staging and screening for recurrent pancreatic cancer.
Casneuf
Veerle
V
Dept of Gastroenterology, De Pintelaan 185, 9000 Gent, Belgium. Veerle.Casneuf@UGent.be
Delrue
Louke
L
Kelles
Annemarie
A
Van Damme
Nancy
N
Van Huysse
Jacques
J
Berrevoet
Frederik
F
De Vos
Martine
M
Duyck
Philippe
P
Peeters
Marc
M
D000328:Adult; D000368:Aged; D001859:Bone Neoplasms / Q000175:diagnosis; D018450:Disease Progression; D005189:False Positive Reactions; D005260:Female; D019788:Fluorodeoxyglucose F18; D005500:Follow-Up Studies; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods*; D008113:Liver Neoplasms / Q000175:diagnosis; D008175:Lung Neoplasms / Q000175:diagnosis; D008207:Lymphatic Metastasis / Q000175:diagnosis; D008297:Male; D008875:Middle Aged; D009362:Neoplasm Metastasis; D009364:Neoplasm Recurrence, Local / Q000175:diagnosis; D009367:Neoplasm Staging; D010190:Pancreatic Neoplasms / Q000175:diagnosis* / Q000473:pathology; D049268:Positron-Emission Tomography / Q000379:methods*; D019275:Radiopharmaceuticals; D012680:Sensitivity and Specificity; D014057:Tomography, X-Ray Computed / Q000379:methods*
D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18