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Intravoxel incoherent motion diffusion-weighted imaging for monitoring the anti-angiogenesis efficacy in a C6 glioma rat model
 
Weishu Hou1, Xiaohu Li1, Hongli Pan1, Man Xu1, Sixing Bi1, Yujun Shen2, Yong Zhang3, Yinfeng Qian1, and Yongqiang Yu1
1the First Affiliated Hospital of Anhui Medical University, Hefei, China, 2Anhui Medical University, Hefei, China, 3GE Healthcare, Shanghai, China

Synopsis

The purpose of this study was to investigate the feasibility of intravoxel incoherent motion (IVIM) diffusion-weighted imaging (DWI) in evaluating early effects of antiangiogenic therapy in a C6 glioma rat model. Twenty-six glioma orthotopic rat models were successfully established 14-16 days after C6 cell inoculation and randomly divided into two groups. The rats in the treated group were administered with Bev while the rats in the control group were administered with vehicle. IVIM-DWI showed significantly decreased D* values and increased ADC and D values corresponding to histological staining in Bev treated tumors.

Purpose

The purpose of this study was to investigate the feasibility of intravoxel incoherent motion (IVIM) diffusion-weighted imaging (DWI) in evaluating early effects of antiangiogenic therapy in a C6 glioma rat model.1,2

Methods

Twenty-six glioma orthotopic rat models were successfully established 14-16 days after C6 cell inoculation and randomly divided into two groups. The rats in the treated group were administered with Bev while the rats in the control group were administered with vehicle (0.9% physiological saline) for 7 days. MRI scans were obtained on days 0, 1, 3, 5, and 7 after treatment, and the quantitative parameters (D,D* and f) of IVIM-DWI were dynamically observed. The tumor volume and average tumor growth rates of rat model was calculated based on T2WI. Histological assessment of HE,CD34,PCNA and Hif1-αstaining were performed on day 7 after antiangiogenic therapy of Bev and vehicle. The ANOVA test was used to compare IVIM-DWI parameters among the 5 time points in treated and control group respectively. The independent-Samples T test was used to compare IVIM-DWI parameters between treated and control groups.The Pearson correlation or Spearman correlation tests were used to analyze the correlation between parameters and histological assessment in the treated group.

Results

After treatment with Bev, the average tumor growth rate in the two groups also differed significantly on day 7 (P = 0.042 and P < 0.001 respectively) (Fig.1). The perfusion-related parameters D* and f decreased in the treated group and demonstrated significant difference with control group on days 3,5 and 7. The diffusion-related parameters ADC and D increased in the treated group and demonstrated significant difference with control group on days 5 and 7 (Fig.2). The ADC,D,D* values all displayed significant difference among the five time points in both both the treated and control group (all P < 0.001) . For intergroup analyses,the ADC and D values in the treated group were higher than that in the control group since day 3 (all P < 0.001),the D* values in the treated group were significantly lower than those in the control group on days 3, 5, and 7 (P = 0.005, P < 0.001, and P < 0.001, respectively) (Fig.3). D* showed positive correlations with MVD (r = 0.886, P = 0.019), while ADC and D showed negative correlation with PCNA (r = -0.848,P = 0.033;r = -0.928,P = 0.008),and D and D* showed negative correlation with PCNA (r = -0.926,P = 0.003;r = -0.879,P = 0.008).

Discussion and Conclusion

IVIM-DWI showed significantly decreased D* values and increased ADC and D values corresponding to histological staining in Bev treated tumors. It was sensitive and precise in predicting the effects of early anti-angiogenesis therapy in a C6 glioma rat model.

Acknowledgements

No acknowledgement found.

References

1. Folkman J. Role of angiogenesis in tumor growth and metastasis. Semin Oncol. 2002;29:15–18.

2. Kim MM, Umemura Y, Leung D. Bevacizumab and glioblastoma: Past, present, and future directions. Cancer J. 2018;24:180–186.

Figures

Fig 1. Tumor volume size (A) and ΔVolume (B) during the treatment course. ***P<0.001 versus the control. Error bars denote standard errors.

Fig 2. Line graphs comparing the IVIM DWI parameters of the tumor, including (a) ADC, (b) D, (c) D*, and (d) f between treated and control groups on day 0,day1 day 3,day 5 and day 7 after treatment. *P<0.05，**P<0.01，***P<0.001.

Fig 3. Box plots comparing the IVIM DWI parameters of the tumor in the treated groups at different time points before and after treatment with Bev. ANOVA followed by the Bonferroni test was used in cases of statistical significance.Error bars denote standard errors.*P<0.05，**P<0.01，***P<0.001.

Proc. Intl. Soc. Mag. Reson. Med. 30 (2022)
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DOI: https://doi.org/10.58530/2022/2668