title: Predictive value of apparent diffusion coefficient in evaluation of colorectal carcinoma hepatic metastases' response to radiofrequency ablation.
abstract: OBJECTIVE
  To establish the apparent diffusion coefficient (ADC) suitability to evaluate the radiofrequency ablation (RFA) outcome in patients with chemotherapy resistant or partially responding colorectal adenocarcinoma liver metastases.
  
  
  METHODS
  A total of 56 patients with 116 metastatic foci over 10 mm in diameter were examined with 1.5 Tesla MRI scanner 1 day before percutaneous RFA treatment. Lesions were evaluated in echo-planar diffusion-weighted images with b = 0, 15 and 500 s/mm(2) . On basis of computed tomography scan at 6 weeks, 3 and 6 months after RFA and serum CEA (carcinoembryonic antigen) level lesion were recognized as responding or nonresponding lesions. ADC values for b = 0-15 and 0-500 s/mm(2) of responding and nonresponding lesions were compared.
  
  
  RESULTS
  Noncomplete ablation concerned 28 lesions. Mean pretreatment ADC values for b = 0-15 and 0-500 s/mm(2) of responding metastases were significantly lower (2.14 and 1.48 × 10(-3) mm(2) /s) than those of nonresponding tumors (2.7 and 1.74 × 10(-3) mm(2) /s). Sensitivity, specificity, and accuracy of ADC values for b = 0-15 s/mm(2) were 79 (95%CI = 59-92), 85 (95%CI = 76-92), 84%; and for b = 0-500 s/mm(2) , the efficacy parameters were, respectively, 78 (95%CI = 56-92), 78 (95%CI = 67-86), and 78%. The P value was under 0.001 for both b parameters.
  
  
  CONCLUSIONS
  The pretreatment ADCs values of chemotherapy resistant or partially responding colorectal adenocarcinoma liver metastatic lesion can be predictive factor of tumors response to RFA therapy.
authors.affiliation: 2nd Department of Radiology, Medical University of Gdansk, Gdansk, Poland.
authors.forename: Edyta
authors.initials: E
authors.lastname: Szurowska
authors.forename: Tomasz K
authors.initials: TK
authors.lastname: Nowicki
authors.forename: Ewa
authors.initials: E
authors.lastname: Izycka-Swieszewska
authors.forename: Dariusz
authors.initials: D
authors.lastname: Zadrozny
authors.forename: Karolina
authors.initials: K
authors.lastname: Markiet
authors.forename: Michal
authors.initials: M
authors.lastname: Studniarek
mesh_terms: D000230:Adenocarcinoma / Q000473:pathology / Q000556:secondary / Q000601:surgery; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D017115:Catheter Ablation / Q000706:statistics & numerical data*; D015179:Colorectal Neoplasms / Q000453:epidemiology / Q000473:pathology* / Q000601:surgery*; D005260:Female; D006801:Humans; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D008113:Liver Neoplasms / Q000473:pathology / Q000556:secondary / Q000601:surgery; D008297:Male; D008875:Middle Aged; D011044:Poland / Q000453:epidemiology; D015995:Prevalence; D011379:Prognosis; D015203:Reproducibility of Results; D012307:Risk Factors; D012680:Sensitivity and Specificity
keywords: CRC; DWI; RFA; liver metastases