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.
Servois
V
V
Department of Radiology and Nuclear Medicine, Institut Curie, 26 rue d'Ulm, 75248 Paris Cedex 05, France.
Mariani
P
P
Malhaire
C
C
Petras
S
S
Piperno-Neumann
S
S
Plancher
C
C
Levy-Gabriel
C
C
Lumbroso-le Rouic
L
L
Desjardins
L
L
Salmon
R J
RJ
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