title: Chemotherapy response assessment in stage IV melanoma patients-comparison of 18F-FDG-PET/CT, CT, brain MRI, and tumormarker S-100B.
abstract: OBJECTIVE
  This study aims to compare the use of 18F-FDG-PET/CT, CT, brain MRI, and tumormarker S-100B in chemotherapy response assessment of stage IV melanoma patients.
  
  
  METHODS
  In 25 patients with stage IV melanoma, FDG-PET/CT and S-100B after 2-3 months (three cycles) of chemotherapy was compared with baseline PET/CT and baseline S-100B. Retrospectively, the response was correlated with the outcome. In patients with clinical suspicion for brain metastases, MRI or CCT was performed.
  
  
  RESULTS
  There was agreement between FDG-PET/CT and CT regarding response to chemotherapy in all patients. There was a clear trend to a longer OS of PET/CT responders (n=10) compared with PET/CT non-responders (n=15; p=0.072) with remarkably better 1-year OS of 80% compared to 40% (p=0.048). There was a significant longer PFS of PET/CT responders compared with PET/CT non-responders (p=0.002). S-100B was normal at baseline in eight of 22 patients where it was available. Chemotherapy response assessment with S-100B failed to show correlation with OS or PFS. Eleven patients developed brain metastases during treatment, first detected by PET/CT in two and by MRI or CCT in nine of 11 patients. Appearance of brain metastases was associated with a poor survival.
  
  
  CONCLUSIONS
  18F-FDG-PET/CT and CT alone are equally suitable for chemotherapy response assessment in melanoma patients and clearly superior to S-100B. PET/CT responders have better early survival, but this is shortlived due to late therapy failure--often with brain recurrence. Additional brain MRI for therapy response assessment in such high-risk patients is mandatory to detect brain metastases missed by PET/CT.
authors.affiliation: Division of Nuclear Medicine, Department of Medical Radiology, University Hospital Zurich, Raemistr. 100, 8091, Zurich, Switzerland. klaus.strobel@usz.ch
authors.forename: Klaus
authors.initials: K
authors.lastname: Strobel
authors.forename: Reinhard
authors.initials: R
authors.lastname: Dummer
authors.forename: Hans C
authors.initials: HC
authors.lastname: Steinert
authors.forename: Katrin Baumann
authors.initials: KB
authors.lastname: Conzett
authors.forename: Karin
authors.initials: K
authors.lastname: Schad
authors.forename: Marisol Pérez
authors.initials: MP
authors.lastname: Lago
authors.forename: Jan D
authors.initials: JD
authors.lastname: Soyka
authors.forename: P
authors.initials: P
authors.lastname: Veit-Haibach
authors.forename: Burkhardt
authors.initials: B
authors.lastname: Seifert
authors.forename: V
authors.initials: V
authors.lastname: Kalff
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000970:Antineoplastic Agents / Q000627:therapeutic use*; D014408:Biomarkers, Tumor / Q000097:blood; D001921:Brain / Q000000981:diagnostic imaging* / Q000473:pathology*; D019788:Fluorodeoxyglucose F18; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008545:Melanoma / Q000097:blood / Q000175:diagnosis / Q000188:drug therapy / Q000556:secondary; D008875:Middle Aged; D009414:Nerve Growth Factors / Q000097:blood*; D017063:Outcome Assessment, Health Care / Q000379:methods; D049268:Positron-Emission Tomography / Q000379:methods*; D011379:Prognosis; D019275:Radiopharmaceuticals; D015203:Reproducibility of Results; D012189:Retrospective Studies; D064568:S100 Calcium Binding Protein beta Subunit; D009418:S100 Proteins / Q000097:blood*; D012680:Sensitivity and Specificity; D013382:Subtraction Technique; D016019:Survival Analysis; D015996:Survival Rate; D014057:Tomography, X-Ray Computed / Q000379:methods*; D016896:Treatment Outcome
chemical_list: D000970:Antineoplastic Agents; D014408:Biomarkers, Tumor; D009414:Nerve Growth Factors; D019275:Radiopharmaceuticals; D064568:S100 Calcium Binding Protein beta Subunit; D009418:S100 Proteins; D019788:Fluorodeoxyglucose F18