title: Treatment planning and volumetric response assessment for Yttrium-90 radioembolization: semiautomated determination of liver volume and volume of tumor necrosis in patients with hepatic malignancy.
abstract: OBJECTIVE
  The primary purpose of this study was to demonstrate intraobserver/interobserver reproducibility for novel semiautomated measurements of hepatic volume used for Yttrium-90 dose calculations as well as whole-liver and necrotic-liver (hypodense/nonenhancing) tumor volume after radioembolization. The secondary aim was to provide initial comparisons of tumor volumetric measurements with linear measurements, as defined by Response Evaluation Criteria in Solid Tumors criteria, and survival outcomes.
  
  
  METHODS
  Between 2006 and 2009, 23 consecutive radioembolization procedures were performed for 14 cases of hepatocellular carcinoma and 9 cases of hepatic metastases. Baseline and follow-up computed tomography obtained 1 month after treatment were retrospectively analyzed. Three observers measured liver, whole-tumor, and tumor-necrosis volumes twice using semiautomated software.
  
  
  RESULTS
  Good intraobserver/interobserver reproducibility was demonstrated (intraclass correlation [ICC] > 0.9) for tumor and liver volumes. Semiautomated measurements of liver volumes were statistically similar to those obtained with manual tracing (ICC = 0.868), but they required significantly less time to perform (p < 0.0001, ICC = 0.088). There was a positive association between change in linear tumor measurements and whole-tumor volume (p < 0.0001). However, linear measurements did not correlate with volume of necrosis (p > 0.05). Dose, change in tumor diameters, tumor volume, and necrotic volume did not correlate with survival (p > 0.05 in all instances). However, Kaplan-Meier curves suggest that a >10% increase in necrotic volume correlated with survival (p = 0.0472).
  
  
  CONCLUSIONS
  Semiautomated volumetric analysis of liver, whole-tumor, and tumor-necrosis volume can be performed with good intraobserver/interobserver reproducibility. In this small retrospective study, measurements of tumor necrosis were suggested to correlate with survival.
authors.affiliation: Department of Radiology, University of California Davis Medical Center, Sacramento, CA 95817, USA. wayne.monsky@ucdmc.ucdavis.edu
authors.forename: Wayne L
authors.initials: WL
authors.lastname: Monsky
authors.forename: Armando S
authors.initials: AS
authors.lastname: Garza
authors.forename: Isaac
authors.initials: I
authors.lastname: Kim
authors.forename: Shaun
authors.initials: S
authors.lastname: Loh
authors.forename: Tzu-Chun
authors.initials: TC
authors.lastname: Lin
authors.forename: Chin-Shang
authors.initials: CS
authors.lastname: Li
authors.forename: Jerron
authors.initials: J
authors.lastname: Fisher
authors.forename: Parmbir
authors.initials: P
authors.lastname: Sandhu
authors.forename: Vishal
authors.initials: V
authors.lastname: Sidhar
authors.forename: Abhijit J
authors.initials: AJ
authors.lastname: Chaudhari
authors.forename: Frank
authors.initials: F
authors.lastname: Lin
authors.forename: Larry-Stuart
authors.initials: LS
authors.lastname: Deutsch
authors.forename: Ramsey D
authors.initials: RD
authors.lastname: Badawi
mesh_terms: D000368:Aged; D006528:Carcinoma, Hepatocellular / Q000000981:diagnostic imaging / Q000628:therapy*; D015331:Cohort Studies; D004621:Embolization, Therapeutic / Q000379:methods*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008099:Liver / Q000000981:diagnostic imaging / Q000473:pathology; D008113:Liver Neoplasms / Q000000981:diagnostic imaging / Q000628:therapy*; D008297:Male; D008875:Middle Aged; D009336:Necrosis; D015588:Observer Variation; D009929:Organ Size; D011829:Radiation Dosage; D019275:Radiopharmaceuticals / Q000627:therapeutic use*; D015203:Reproducibility of Results; D012189:Retrospective Studies; D016019:Survival Analysis; D014057:Tomography, X-Ray Computed; D016896:Treatment Outcome; D047368:Tumor Burden; D015021:Yttrium Radioisotopes / Q000627:therapeutic use*
chemical_list: D019275:Radiopharmaceuticals; D015021:Yttrium Radioisotopes