Preoperative staging of liver metastases from uveal melanoma by magnetic resonance imaging (MRI) and fluorodeoxyglucose-positron emission tomography (FDG-PET).
BACKGROUND
Microscopically complete (R0) resection of metastases from uveal melanoma prolongs median overall survival compared to incomplete surgery. The aim of this study was to compare the sensitivity of dynamic-enhanced magnetic resonance imaging (MRI) with fluorodeoxyglucose-positron emission tomography (FDG-PET) in the preoperative diagnosis of liver metastases from uveal melanoma.


METHODS
Fifteen consecutive patients (mean age: 56 years) underwent FDG-PET and liver MRI. Extrahepatic metastatic disease was excluded by whole body computed tomography and bone scintigraphy. MRI and FDG-PET were performed with a mean of 19 days (range: 1-30) before surgery. Imaging findings were compared with surgical (including intraoperative ultrasonography) and histological findings on a lesion by lesion analysis.


RESULTS
R0 resection was performed in 12 patients. A total of 28 lesions were resected with 27 histologically proven metastases. Nine lesions were smaller than 5mm, 7 measured 5-10mm and 11 were larger than 10mm. Sensitivity and positive predictive value were 67% and 95% for MRI compared to 41% and 100% for FDG-PET. The difference between the two modalities was statistically significant (p=0.01; McNemar test). In remaining 3 patients, diffuse miliary disease (>10 capsular lesions) was discovered intraoperatively, and was suspected on preoperative MRI in 2 cases. Only one extrahepatic lesion identified by FDG-PET was falsely positive.


CONCLUSIONS
In this preliminary study, MRI was superior to FDG-PET for staging of liver metastases from uveal melanoma. Although miliary disease was suggested by MRI in some cases, preoperative confirmation remains imperfect.
Department of Radiology and Nuclear Medicine, Institut Curie, 26 rue d'Ulm, 75248 Paris Cedex 05, France.
V
V
Servois
P
P
Mariani
C
C
Malhaire
S
S
Petras
S
S
Piperno-Neumann
C
C
Plancher
C
C
Levy-Gabriel
L
L
Lumbroso-le Rouic
L
L
Desjardins
R J
RJ
Salmon
D000328:Adult; D000368:Aged; D005260:Female; D019788:Fluorodeoxyglucose F18; D006801:Humans; D008113:Liver Neoplasms / Q000175:diagnosis* / Q000556:secondary* / Q000601:surgery; D008279:Magnetic Resonance Imaging; D008297:Male; D008545:Melanoma / Q000175:diagnosis* / Q000556:secondary* / Q000601:surgery; D008875:Middle Aged; D009367:Neoplasm Staging; D049268:Positron-Emission Tomography; D011237:Predictive Value of Tests; D019275:Radiopharmaceuticals; D012680:Sensitivity and Specificity; D014604:Uveal Neoplasms / Q000473:pathology*
D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18