Diffusion-Related MRI Parameters for Assessing Early Treatment Response of Liver Metastases to Cytotoxic Therapy in Colorectal Cancer.
OBJECTIVE
The objective of our study was to evaluate early therapeutic response after cytotoxic chemotherapy in patients with liver metastasis from colorectal cancer (CRC) using intravoxel incoherent motion (IVIM) DWI and dynamic contrast-enhanced MRI (DCE-MRI).


METHODS
Nineteen patients with liver metastasis from CRC underwent DCE-MRI and IVIM DWI at baseline and after the first cycle of chemotherapy. IVIM DWI parameters including the apparent diffusion coefficient (ADC), true diffusion coefficient (D), pseudodiffusion coefficient (D*), and perfusion fraction (f) and DCE-MRI perfusion parameters including the volume transfer constant (K(trans)), reverse volume transfer constant (Kep), extravascular extracellular volume fraction (Ve), and initial area under the concentration curve in 60 seconds (iAUC) were calculated. The response evaluation was based on Response Evaluation Criteria in Solid Tumors version 1.1.


RESULTS
There were eight responding and 11 nonresponding patients. ADC (baseline value vs value after first cycle of chemotherapy [mean ± SD]: 1191.9 ± 232.2 vs 1263.5 ± 266.4 × 10(-3) mm(2)/s; p = 0.012), D (1085.9 ± 232.9 vs 1173.5 ± 248.9 × 10(-3) mm(2)/s; p = 0.012), and f (173.7% ± 39.8% vs 133.5% ± 28.3%; p = 0.017) showed a significant change after the first cycle of chemotherapy in the response group, whereas ADC and D showed no significant change in the nonresponse group. In addition, DCE-MRI perfusion parameters showed no significant changes. A correlation was found between each of perfusion-related IVIM parameters and the DCE-MRI parameters before chemotherapy (r = 1.33, p > 0.05).


CONCLUSIONS
Diffusion-related MRI parameters are useful for the early prediction of therapeutic response after cytotoxic chemotherapy for liver metastasis from CRC.
1 Department of Radiology, Seoul National University Hospital, 101 Daehangno, Jongno-gu, Seoul 110-744, Republic of Korea.|2 Institute of Radiation Medicine, Seoul National University College of Medicine, Seoul, Republic of Korea.
Jung Hoon
JH
Kim
1 Department of Radiology, Seoul National University Hospital, 101 Daehangno, Jongno-gu, Seoul 110-744, Republic of Korea.
Ijin
I
Joo
3 Department of Internal Medicine, Seoul National University Hospital, Jongno-Gu, Seoul, Republic of Korea.
Tae-Yong
TY
Kim
3 Department of Internal Medicine, Seoul National University Hospital, Jongno-Gu, Seoul, Republic of Korea.
Sae-Won
SW
Han
4 Department of Radiology, Soonchunhyang University Hospital, Hannam-Dong, Youngsan-Ku, Seoul, Republic of Korea.
Yong Jae
YJ
Kim
1 Department of Radiology, Seoul National University Hospital, 101 Daehangno, Jongno-gu, Seoul 110-744, Republic of Korea.|2 Institute of Radiation Medicine, Seoul National University College of Medicine, Seoul, Republic of Korea.
Jeong Min
JM
Lee
1 Department of Radiology, Seoul National University Hospital, 101 Daehangno, Jongno-gu, Seoul 110-744, Republic of Korea.|2 Institute of Radiation Medicine, Seoul National University College of Medicine, Seoul, Republic of Korea.
Joon Koo
JK
Han
D000368:Aged; D015179:Colorectal Neoplasms / Q000473:pathology*; D003287:Contrast Media; D038524:Diffusion Magnetic Resonance Imaging / Q000379:methods*; D005260:Female; D006801:Humans; D007089:Image Enhancement; D007090:Image Interpretation, Computer-Assisted; D008113:Liver Neoplasms / Q000000981:diagnostic imaging* / Q000188:drug therapy* / Q000556:secondary; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D016896:Treatment Outcome
D003287:Contrast Media
DWI; dynamic contrast-enhanced MRI; focal liver lesion; intravoxel incoherent motion; therapeutic response