Jin Cheng MD, Presenter: Nothing to Disclose

Jie Deng PhD, Abstract Co-Author: Nothing to Disclose

Yi Wang MD, Abstract Co-Author: Nothing to Disclose

He Wang PhD, Abstract Co-Author: Nothing to Disclose

Feng Pan, Abstract Co-Author: Nothing to Disclose

Weizhen Wu MD, Abstract Co-Author: Nothing to Disclose

Nan Hong MD, Abstract Co-Author: Nothing to Disclose

To determine the capability of intravoxel incoherent motion (IVIM) diffusion-weighted (DW) MRI in evaluating therapeutic response in a mouse gastric cancer model.

The xenografts bearing MKN-45 human gastric adenocarcinoma were randomly separated in a control group and a group receiving chemotherapy. Fluorouracil and Calcium Folinate were administrated in xenografts for 5 consecutive days starting on day 0. DWMRI with 14 b-values (0-1500 s/mm2) was performed before (day -1) and after treatment (day 3 and day 7). Pure diffusion coefficient (D), perfusion fraction (f) and perfusion coefficient (D*) were calculated by the bi-exponential model S/S0=(1-f) e^(-bD)+fe^(-b(D+D*)). Apparent diffusion coefficient (ADC) was also calculated. Median changes ofΔADC%, ΔD%, ΔD*% and Δf% from baseline (day -1) measurements were calculated, and analyzed by Mann-Whitney test.

The increase in f of the treated group was significantly higher than the control group, at day 3 (Δf %treated=83.7% and Δf %control=14.3%, P=0.0248) and day 7 (Δf %treated=63.7% and Δf %control=-2.6%, P=0.0192). D*of the treated group decreased at both day 3 (ΔD*%=-27.4%) and day 7 (ΔD*% = -21.1%), whereas D* of the control group increased at day 3 (ΔD*%=14.3%) but decreased at day 7 (ΔD*%=-5.5%). ADC increase of the treated group (ΔADC%=15.8%) was higher than that of control group (ΔADC%=10.7%) at day 3. However, the significant differences in ΔD*% and ΔADC% were not reached.

The perfusion fraction f that may associate with tumor tissue microvascular volume may serve as a valuable imaging biomarker of response to chemotherapy in gastric adenocarcinoma.

IVIM–derived perfusion fraction f involving diffusion weighted MRI with multiple b values would server as greater imaging biomarker to monitor chemotherapeutic response in gastric cancer compared with ADC values, pure diffusion coefficient D, and perfusion coefficient D* .

Cheng, J, Deng, J, Wang, Y, Wang, H, Pan, F, Wu, W, Hong, N, Evaluation of Chemotherapy Response of Gastric Cancer in a Mouse Model Using the Intravoxel Incoherent Diffusion-weighted MRI .  Radiological Society of North America 2014 Scientific Assembly and Annual Meeting, - ,Chicago IL. http://archive.rsna.org/2014/14045497.html