TY - JOUR ID - 75616 TI - Correlation Of Apparent Diffusion Coefficient With Tumor Grade And Ki-67 Proliferative Index Of Meningioma JO - Iranian Congress of Radiology JA - ICRJ LA - en SN - AU - Sabet, Soheil AU - Samadov, Parviz AU - Aydın Gündoğmuş, Cemal AU - Uyar Bozkurt, Süheyla AU - Ekinci, Gazanfer AD - Istanbul Bilim University AD - Marmara University Y1 - 2018 PY - 2018 VL - 34 IS - 4 SP - 111 EP - 111 KW - meningioma KW - Apparent diffusion coefficient KW - Magnetic resonance imaging KW - Ki-67 KW - Tumor grade DO - 10.22034/icrj.2018.75616 N2 - Background: Meningioma, the most frequent intracranial, extra-axial tumor, constitutes %13-26 of all intracranial neoplasms. Less than %10 of all meningiomas account for grade II or III (atypical-anaplastic) based on WHO criteria. Preoperative estimation of tumor grade might play a directive role for neurosurgeons. Higher Ki-67 index is associated with increased risk of tumor recurrence affecting the prognosis.  Objectives: We aimed to investigate the efficiency of diffusion weighted imaging properties in preoperative estimation of tumor grade and correlation between ADC values and Ki-67 proliferative index. To our knowledge this is the largest single tertiary center study series in English literature investigating association between DWI and histopathologic features of meningiomas.  Materials and Methods: Pre-operative brain MR examinations of 206 consecutive patients were evaluated retrospectively. ADC values of 6 ROI’s in two consecutive slices were measured and the average ADC value was calculated for each lesion. Proliferation activity of the tumors which were identified with ki-67 index was recorded. The meningiomas were classified into low grade (WHO grade I) and high grade (WHO grade II/III) groups.  Results: Median ADC value in low and high grade lesions were 826.23 ± 134.567 × 10-6 mm2s-1 and 732.48 ± 150.846 × 10-6 mm2s-1 respectively. Threshold of 750.5 × 10-6 mm2s-1 for ADC value, yielded the best sensitivity (%74), specifity (%72) and accuracy (%73.79) in discriminating low and high grade meningiomas. The area under curve in ROC analysis was 0,742. Determination of 750.5 × 10-6 mm2s-1 as threshold ADC value, led to 95.04% and 27.69% negative and positive predictive values, respectively. There was also a significant negative correlation between ADC value and Ki-67 index level (r = - 0,26 , p < 0.001 )  Conclusion: ADC value is an important parameter in characterization of meningioma with implications for prognosis and management. ADC values can also predict tumor proliferative index providing the advantage of proper surgical approach and further use of fractionated radiotherapy or stereotactic single-dose radiosurgery to decrease the possibility of tumor recurrence.   UR - https://www.icrjournal.ir/article_75616.html L1 - ER -