title: Predicting Treatment Response of Colorectal Cancer Liver Metastases to Conventional Lipiodol-Based Transarterial Chemoembolization Using Diffusion-Weighted MR Imaging: Value of Pretreatment Apparent Diffusion Coefficients (ADC) and ADC Changes Under Therapy.
abstract: OBJECTIVE
  To use absolute pretreatment apparent diffusion coefficients (ADC) derived from diffusion-weighted MR imaging (DWI) to predict response to repetitive cTACE for unresectable liver metastases of colorectal carcinoma (CRLM) at 1 and 3 months after start of treatment.
  
  
  METHODS
  Fifty-five metastases in 34 patients were examined with DWI prior to treatment and 1 month after initial cTACE. Treatment was performed in 4-week intervals. Response was evaluated at 1 and 3 months after start of therapy. Metastases showing a decrease of ≥30% in axial diameter were classified as responding lesions.
  
  
  RESULTS
  One month after initial cTACE, seven lesions showed early response. There was no significant difference in absolute pretreatment ADC values between responding and non-responding lesions (p = 0.94). Three months after initial cTACE, 17 metastases showed response. There was a significant difference (p = 0.021) between absolute pretreatment ADC values of lesions showing response (median 1.08 × 10-3mm2/s) and no response (median 1.30 × 10-3mm2/s). Pretreatment ADC showed fair diagnostic value to predict response (AUC 0.7). Lesions showing response at 3 months also revealed a significant increase in ADC between measurements before treatment and at one month after initial cTACE (p < 0.001). Applying an increase in ADC of 12.17%, response at 3 months after initial cTACE could be predicted with a sensitivity and specificity of 77 and 74%, respectively (AUC 0.817). Furthermore, there was a strong and significant correlation (r = 0.651, p < 0.001) between percentage change in size after third cTACE and percentage change in ADC.
  
  
  CONCLUSIONS
  In patients with CRLM, ADC measurements are potential biomarkers for assessing response to cTACE.
authors.affiliation: Department of Diagnostic and Interventional Radiology, University Hospital Frankfurt, Theodor-Stern-Kai 7, 60590, Frankfurt am Main, Germany. mlahrsow@gmail.com.
authors.forename: Maximilian
authors.identifier: http://orcid.org/0000-0003-1216-5227
authors.initials: M
authors.lastname: Lahrsow
authors.affiliation: Department of Diagnostic and Interventional Radiology, University Hospital Frankfurt, Theodor-Stern-Kai 7, 60590, Frankfurt am Main, Germany.
authors.forename: Moritz H
authors.initials: MH
authors.lastname: Albrecht
authors.affiliation: Department of Radiology and Radiological Science, Medical University of South Carolina, 25 Courtenay Drive, Charleston, SC, 29425, USA.
authors.forename: Matthew W
authors.initials: MW
authors.lastname: Bickford
authors.affiliation: Department of Diagnostic and Interventional Radiology, University Hospital Frankfurt, Theodor-Stern-Kai 7, 60590, Frankfurt am Main, Germany.
authors.forename: Thomas J
authors.initials: TJ
authors.lastname: Vogl
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D016461:Chemoembolization, Therapeutic / Q000379:methods*; D015179:Colorectal Neoplasms / Q000000981:diagnostic imaging / Q000628:therapy*; D038524:Diffusion Magnetic Resonance Imaging / Q000379:methods*; D004621:Embolization, Therapeutic; D004998:Ethiodized Oil; D005260:Female; D006801:Humans; D008113:Liver Neoplasms / Q000000981:diagnostic imaging / Q000556:secondary* / Q000628:therapy*; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D012680:Sensitivity and Specificity; D016896:Treatment Outcome
chemical_list: D004998:Ethiodized Oil
keywords: Apparent diffusion coefficient (ADC); Colorectal cancer liver metastases (CRLM); Conventional transarterial chemoembolization (cTACE); Diffusion-weighted imaging (DWI)