MR Electrical Properties Tomography (MREPT) at 9.4T to Assess Treatment Response of Choline Kinase Inhibition on GL261 Glioblastoma

Abstract AIMS To monitor changes in tissue-conductivity based MR parameter in response to JAS239 treatment in preclinical glioblastoma model. METHOD C57BL/6 mice were injected intracranially with 5x105 GL261 glioblastoma cells and tumours were observed on T2 weighted MRI. Mice were imaged on day 0 (baseline), day 3 , 6 of treatment and post-treatment day 10. For MREPT, multi-slice-multi-echo sequence was used. Laplacian algorithm was employed to obtain the phase-based MREPT image reconstruction. RESULTS Saline treated mice showed a greater increase in tumour volume compared to JAS239 treated animals with respect to baseline. Percentage changes in conductivity values with respect to baseline from saline treated mice were compared to JAS239 treated animals. JAS239 group showed a slight increase in mean conductivity on day 3 and 6 compared to saline group. There were no statistically (p> 0.05) significant differences between the two groups. 4 days after treatment completion (Day10), the mean of conductivity values of JAS239 treated animals compared to saline treated animals showed no statistically (p> 0.05) significant differences. These results may indicate that GL261 tumour model is treatment resistant. Our findings agree with a study conducted by Bhaduri et al, where tumours were treated with JAS239. CONCLUSION EPT technique provides unique data on tissue conductivity which can be used to improve the assessment of treatment response in glioblastoma. MREPT parameter might be insensitive to evaluate choline kinase inhibitor. For future work, this technique can be incorporated into multiparametric MRI to complement diffusion and perfusion-weighted imaging of assessing treatment response in glioblastoma.