NI-17 Evaluation of preoperative apparent diffusion coefficient (ADC) of peritumoral FLAIR high lesion and histopathological features in patients with glioblastoma

Objective: In removal of the glioblastoma, maximum and safe removal is desired for recurrence prevention with functional preservation. In recent years, the setting of the removal range has also been studied not only the contrast enhanced lesions, but also the surrounding FLAIR high signal lesion. We are studying the prediction of the site that is likely to occur recurrence in the FLAIR high signal lesion of glioblastoma, and we are focusing on the ADC of pre-operative MRI as an index. The purpose of this study is to evaluate the ADC and the actual pathological tissue image in the FAIR high signal lesion around the contrast enhanced lesion of glioblastoma. Method: We examined the case of removal of the glioblastoma treated in our department. Analysis was performed using a pathological tissue specimen of excised tumors and their surrounding tissues in each case, and the ADC value of pre-operative MRI. Pathological tissue image and ADC values of FAIR high signal lesion were compared. Results: 19 tissue samples which were taken from the FLAIR high signal lesion around the contrast enhanced tumor from 10 cases. For a total of 19 locations, it was compared with the histopathological features of the site. As a result, in the low part of the ADC value in the preoperative MRI relatively had high cell density of atypical cells, it was often exhibited findings that infiltration of tumor cells is suspected. Conclusion: In general, ADC is said to suggest an increase in cell density and thus infiltration of tumor cells. However, the same findings were obtained in the pre-operative MRI examined this time. Since ADC also suggests cell density and tumor infiltration in pre-operative MRI, ADC of pre-operative MRI was considered useful for examination of the removal range and radiation therapy planning in surgery for glioblastoma.