title: Islet cell liver metastases: assessment of volumetric early response with functional MR imaging after transarterial chemoembolization.
abstract: OBJECTIVE
  To assess early response to transarterial chemoembolization by using volumetric functional magnetic resonance (MR) imaging in patients with islet cell liver metastases (ICLMs).
  
  
  METHODS
  This retrospective institutional review board-approved HIPAA-compliant study included 215 ICLMs in 26 patients (15 men, 11 women; mean age, 59.7 years; age range, 37-79 years). Volumetric measurements were performed by an experienced radiologist on diffusion-weighted and contrast material-enhanced MR images at baseline and 1-month follow-up. Measurements included mean change (three-dimensional [3D] mean apparent diffusion coefficient [ADC], 3D mean enhancement) and percentage of tumor with change above a predetermined threshold (3D threshold ADC, 3D threshold enhancement). Response by volumetric measurements at 1-month follow-up was compared with Response Evaluation Criteria in Solid Tumors (RECIST) at 6-month follow-up. Lesions that had complete or partial response were considered responders, while those with stable or progressive disease were considered nonresponders. Statistical analysis included the t test, receiver operating characteristic (ROC) curve analysis, and logistic regression analysis.
  
  
  RESULTS
  RECIST criteria at 6-month follow-up indicated 78 (36.3%) lesions responded, while 137 (63.7%) did not. The increase in 3D mean ADC was significantly higher in responders than in nonresponders (median, 26.2% vs 10.9%; P<.001). The 3D threshold ADC was 71.1% in responders and 47.6% in nonresponders (P<.001). Decrease in 3D mean arterial enhancement (AE) was significantly higher in responders than in nonresponders (median, 40.5% vs 18.0%; P<.001). Decrease in 3D mean venous enhancement (VE) was significantly higher in responders than in nonresponders (median, 28.0% vs 10.0%; P<.001). The 3D threshold VE and 3D threshold AE did not differ between responders and nonresponders. In unadjusted logistic regression analyses, 3D mean ADC and 3D threshold ADC had the highest odds ratio (1.02 and 1.03, respectively) and the largest area under the ROC curve (0.698 and 0.695, respectively).
  
  
  CONCLUSIONS
  Volumetric functional MR imaging could be used to predict early response of hepatic ICLMs to therapy and to distinguish between responders and nonresponders.
authors.affiliation: Department of Radiology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China.
authors.forename: Zhen
authors.initials: Z
authors.lastname: Li
authors.forename: Susanne
authors.initials: S
authors.lastname: Bonekamp
authors.forename: Vivek Gowdra
authors.initials: VG
authors.lastname: Halappa
authors.forename: Celia Pamela
authors.initials: CP
authors.lastname: Corona-Villalobos
authors.forename: Timothy
authors.initials: T
authors.lastname: Pawlik
authors.forename: Nik
authors.initials: N
authors.lastname: Bhagat
authors.forename: Diane
authors.initials: D
authors.lastname: Reyes
authors.forename: Hong
authors.initials: H
authors.lastname: Lai
authors.forename: Jean F
authors.initials: JF
authors.lastname: Geschwind
authors.forename: Ihab R
authors.initials: IR
authors.lastname: Kamel
mesh_terms: D000328:Adult; D000368:Aged; D016461:Chemoembolization, Therapeutic / Q000379:methods*; D003287:Contrast Media; D018450:Disease Progression; D004317:Doxorubicin / Q000008:administration & dosage; D004998:Ethiodized Oil / Q000008:administration & dosage; D005260:Female; D019786:Gadolinium DTPA; D006801:Humans; D021621:Imaging, Three-Dimensional; D007515:Islets of Langerhans / Q000473:pathology*; D008113:Liver Neoplasms / Q000556:secondary* / Q000628:therapy*; D016015:Logistic Models; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D012372:ROC Curve; D012189:Retrospective Studies; D018709:Statistics, Nonparametric; D015996:Survival Rate
chemical_list: D003287:Contrast Media; D004998:Ethiodized Oil; D004317:Doxorubicin; C064925:gadodiamide; D019786:Gadolinium DTPA