PURPOSE: 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. MATERIALS AND 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. CONCLUSION: 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.
PURPOSE: 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. MATERIALS AND 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. CONCLUSION: 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.