Utility of FDG PET/CT and brain MRI in melanoma patients with increased serum S-100B level during follow-up.
BACKGROUND
The serum level of the S-100B protein is increasingly used as a tumor marker in melanoma patients. The aims of this study were to assess the clinical relevance of increased S-100B during follow up of high-risk melanoma patients and to determine the value of subsequent whole-body PET/CT and brain MRI.


METHODS
A retrospective analysis was performed of all 46 melanoma patients with a normal history and physical examination who were found to have an elevated serum S-100B level (> or =0.10 microg/L) during follow-up between August 2006 and March 2009. Suspicious lesions on FDG PET/CT were biopsied for histological or cytological confirmation or were imaged further and followed if no pathology confirmation could be obtained.


RESULTS
The positive predictive value of an elevated serum S-100B was 50%. PET/CT revealed hypermetabolic lesions in 27 of the 46 patients (59%). PET/CT was never false negative as confirmed by median follow-up of 1 year but was false positive in 4 patients. MRI revealed brain metastases in 1 patient (2%). Of the 23 patients with a true positive PET/CT scan, 6 (26%) received surgical treatment with curative intent; the other 17 (74%) received palliative treatment or supportive care. The survival of patients with a normal PET/CT was longer than patients with a positive PET/CT (P = .002).


CONCLUSIONS
An elevated serum S-100B during follow-up of high-risk melanoma patients has a modest 50% positive predictive value for recurrent disease. Subsequent PET/CT and MRI can identify patients with recurrent disease.
Department of Nuclear Medicine, The Netherlands Cancer Institute/Antoni van Leeuwenhoek Hospital, Amsterdam, The Netherlands. t.aukema@nki.nl
Tjeerd S
TS
Aukema
Renato A Valdés
RA
Olmos
Catharina M
CM
Korse
Bin B R
BB
Kroon
Michel W J M
MW
Wouters
Wouter V
WV
Vogel
Johannes M G
JM
Bonfrer
Omgo E
OE
Nieweg
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D014408:Biomarkers, Tumor / Q000097:blood*; D001932:Brain Neoplasms / Q000097:blood / Q000175:diagnosis* / Q000556:secondary; D019788:Fluorodeoxyglucose F18; D005500:Follow-Up Studies; D006801:Humans; D008279:Magnetic Resonance Imaging; D008545:Melanoma / Q000097:blood / Q000175:diagnosis* / Q000556:secondary; D008875:Middle Aged; D009414:Nerve Growth Factors / Q000097:blood*; D049268:Positron-Emission Tomography / Q000379:methods; D011237:Predictive Value of Tests; D019275:Radiopharmaceuticals; D012189:Retrospective Studies; D064568:S100 Calcium Binding Protein beta Subunit; D009418:S100 Proteins / Q000097:blood*; D012680:Sensitivity and Specificity; D012878:Skin Neoplasms / Q000097:blood / Q000175:diagnosis* / Q000473:pathology; D014057:Tomography, X-Ray Computed; D051598:Whole Body Imaging
D014408:Biomarkers, Tumor; D009414:Nerve Growth Factors; D019275:Radiopharmaceuticals; D064568:S100 Calcium Binding Protein beta Subunit; D009418:S100 Proteins; D019788:Fluorodeoxyglucose F18