Experimental study of diffusion kurtosis imaging in predicting radiotherapy sensitivity of esophageal carcinoma

Abstract

Objective To explore the value of diffusion kurtosis imaging (DKI) in predicting radiotherapy sensitivity of esophageal cancer from the animal model level. Methods BALB/c nude mice were subcutaneously injected with Eca-109 cell lines to form xenograft tumors. The tumors received a single dose of 15 Gy (6 MV X-rays) in the experimental group or had no any treatment as control. The volume of transplanted tumor, the change of ADC, MK and MD values, and the tumor cell density and necrosis ratio of these two groups were observed at the corresponding time points. Results The growth of xenograft volume in the experimental group was suppressed and it was significantly smaller than that in the control group (t=3.206-6.149, P<0.05) at the 7th day after radiotherapy. From the 3rd day after radiotherapy, the ADC and MD values of the experimental group were significantly higher than those of the control group, and the MK values was lower than those in the control group (tADC=-11.018--2.049, tMD=-6.609- -2.052, tMK=2.492-9.323, P<0.05). Meanwhile, the tumor cell density of the control group was higher than that of the experimental group, and the proportion of necrosis in the experimental group was higher than that in the control group (tdensity=-8.387--2.239, tnecrosis=2.980-17.430, P<0.05). Conclusions A single large dose radiation could inhibit the growth of xenograft. ADC, MK, MD values changed at the early stage prior to morphological changes of tumor in consistent with the change of cell density and necrosis ratio. DKI has the potential value in predicting radiotherapy sensitivity of esophageal carcinoma. Key words: Diffusion kurtosis imaging(DKI); Diffusion weighted imaging(DWI); Mean diffusion kurtosis(MK); Mean diffusion coefficient(MD); Apparent dispersion coefficient(ADC)