title: Evaluation of radiological prognostic factors of hepatic metastases in patients with non-functional pancreatic neuroendocrine tumors.
abstract: OBJECTIVE
  There are different therapeutic options in non-functional well to moderately differentiated (G1 and G2) pancreatic neuroendocrine tumors (pNET) with unresectable hepatic metastases including systemic chemotherapy and novel molecular targeted therapies. Treatment with somatostatin analogs (SSA) as antiproliferative agents is optional. At initial diagnosis watchful waiting until tumor progression is a well-established approach. Goal of this study was to evaluate imaging features as potential prognostic factors predicting early tumor progression in order to select patients that might benefit from an earlier initiation of medical treatment.
  
  
  METHODS
  In 44 patients we correlated tumor grade, chromogranin A (CgA) levels, treatment with SSA and imaging features of hepatic metastases on contrast-enhanced multiphase CT and MR imaging with time to tumor progression (TTP) according to RECIST 1.0.
  
  
  RESULTS
  In the total patient cohort none of the tested imaging features was found to be a statistically significant prognostic factor for TTP. Since treatment with SSA was associated with an increased TTP we also analyzed a subgroup of 30 patients not treated with SSA. In this subgroup of patients hypoenhancement of hepatic metastases during early contrast phases was found to be a negative prognostic factor for early tumor progression within 12 months (p=0.039). The other evaluated parameters including hepatic tumor load, number of metastases, and presence of regressive morphological changes did not reveal significant results.
  
  
  CONCLUSIONS
  Hypovascularization of liver metastases from G1 and G2 pNET reflected by hypoenhancement during the early contrast phases seems to be associated with early tumor progression. In patients with hypoenhancing metastases repeated biopsy for reassessment of grading of these metastases, and early initiation of therapy should be considered.
authors.affiliation: Klinik für Radiologie, Campus Virchow-Klinikum, Charité - Universitätsmedizin Berlin, Germany.
authors.forename: Timm
authors.initials: T
authors.lastname: Denecke
authors.forename: Alexander D J
authors.initials: AD
authors.lastname: Baur
authors.forename: Claudia
authors.initials: C
authors.lastname: Ihm
authors.forename: Ingo G
authors.initials: IG
authors.lastname: Steffen
authors.forename: Elisabeth
authors.initials: E
authors.lastname: Tischer
authors.forename: Ruza
authors.initials: R
authors.lastname: Arsenic
authors.forename: Andreas
authors.initials: A
authors.lastname: Pascher
authors.forename: Bertram
authors.initials: B
authors.lastname: Wiedenmann
authors.forename: Marianne
authors.initials: M
authors.lastname: Pavel
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D015331:Cohort Studies; D005260:Female; D006801:Humans; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D008113:Liver Neoplasms / Q000175:diagnosis* / Q000556:secondary*; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D009367:Neoplasm Staging; D018358:Neuroendocrine Tumors / Q000175:diagnosis* / Q000556:secondary*; D010190:Pancreatic Neoplasms / Q000175:diagnosis*; D011379:Prognosis; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D014057:Tomography, X-Ray Computed / Q000379:methods*
keywords: Liver; Metastases; Neuroendocrine tumors; Prognosis; Staging