title: Radioembolization with yttrium-90 resin microspheres for neuroendocrine tumor liver metastases.
abstract: OBJECTIVE
  We aimed to evaluate the effectiveness and safety of radioembolization with yttrium-90 (90Y) microspheres in cases with unresectable neuroendocrine tumor liver metastases (NETLMs).
  
  
  METHODS
  Thirty patients (mean age, 55 years) underwent resin-based 90Y radioembolization for unresectable NETLM at a single institution between April 2008 and June 2013. Post-treatment tumor response was assessed by cross-sectional imaging using the Response Evaluation Criteria in Solid Tumors (RECIST). Prognostic variables that affected survival were determined.
  
  
  RESULTS
  The mean follow-up was 23.0±19.4 months and the median overall survival was 39 months (95% CI, 12.6-65.4 months), with one- and two-year survival rates of 71% and 45%, respectively. Imaging follow-up using RECIST at three-month intervals demonstrated partial response in 43%, complete remission in 3%, stable disease in 37%, and progressive disease in 17% of patients. Extent of tumor involvement was found to have a statistically significant influence on overall survival (P = 0.03). The existence of extrahepatic disease at the time of radioembolization, radiographic response, age, and primary neuroendocrine tumor site were not significant prognostic factors.
  
  
  CONCLUSIONS
  The current study demonstrates the effectiveness and safety of radioembolization for the treatment of unresectable NETLMs. We identified that the extent of tumor involvement has a significant effect on overall survival. The use of imaging methods reflecting metabolic activity or cellularity such as scintigraphy or diffusion-weighted MRI would be more appropriate, for the response evaluation of liver metastases after radioembolization.
authors.affiliation: Department of Radiology, Ankara University Medical School, Ankara, Turkey. ahmet.peker@ankara.edu.tr.
authors.forename: Ahmet
authors.initials: A
authors.lastname: Peker
authors.forename: Okan
authors.initials: O
authors.lastname: Çiçek
authors.forename: Çiğdem
authors.initials: Ç
authors.lastname: Soydal
authors.forename: Nuriye Özlem
authors.initials: NÖ
authors.lastname: Küçük
authors.forename: Sadık
authors.initials: S
authors.lastname: Bilgiç
mesh_terms: D000328:Adult; D000368:Aged; D004621:Embolization, Therapeutic / Q000295:instrumentation / Q000379:methods*; D005260:Female; D006801:Humans; D008113:Liver Neoplasms / Q000000981:diagnostic imaging / Q000556:secondary* / Q000628:therapy*; D008297:Male; D008863:Microspheres; D008875:Middle Aged; D018358:Neuroendocrine Tumors / Q000473:pathology / Q000532:radiotherapy / Q000628:therapy*; D011379:Prognosis; D012189:Retrospective Studies; D016019:Survival Analysis; D016896:Treatment Outcome; D015021:Yttrium Radioisotopes / Q000008:administration & dosage*
chemical_list: D015021:Yttrium Radioisotopes