두개 내 신경 교종의 18F-FDOPA 섭취에 영향을 미치는 임상병리학적 소견에 대한 평가

Abstract

Purpose: While 18F-FDOPA PET is clinically useful in the evaluation of brain tumors, tumor uptake of 18F-FDOPA are known to vary. We investigated clinical, genetic, pathologic findings and MR findings that could affect 18F-FDOPA uptake of intracranial gliomas to improve the interpretation of 18F-FDOPA PET and the determination of therapeutic plans based on it. Methods: We retrospectively reviewed 21 consecutive patients (M/F=13/8; median age 50 years; age range 21-72 years) with pathologically confirmed intracranial glioma and 9 patients (M/F=4/5; median age 49 years, age range 31-62 years) with non-tumorous lesions, who underwent both 18F-FDOPA brain PET/CT and brain MR imaging for preoperative evaluation from July 2015 to June 2018. 18F-FDOPA PET images were acquired during 30min immediately after injection. We calculated SUV ratio (SUVR) of lesion to reference (contralateral striatum or contralateral normal white matter) on 10-30 min summed image and the washout ratio of SUVR. In glioma patients, we evaluated the association between FDOPA uptake and clinicopathologic findings including the histology, tumor grade, IDH mutations and conventional MR findings (tumor size, location, laterality, gadolinium enhancement, proportion of non-contrast enhancing tumor, proportion of necrosis, and proportion of edema), and perfusion MR parameters (leakage-correlated rCBV/rCBF, vascular permeability). Results: 18F-FDOPA uptake of gliomas in terms of SUVRstriatum and SUVRwhite matte was significantly higher than no-tumorous lesions (p<0.001). SUVRstriatum was associated with tumor grade, IDH mutation, histology, proportion of necrosis on MRI (p<0.05). Only proportion of non-enhancement on MRI is associated with SUVRwhite matter (p=0.005). There were no clinicopathologic findings associated with the washout of 18F-FDOPA uptake in gliomas (p>0.05). There was no significant correlation between SUVR and perfusion MR parameters in gliomas (p>0.05), although there was a positive correlation between the degree of gadolinium enhancement on MRI and SUVRStriatum (Spearman’s rho=0.881, p=0.002) or SUVRWhite matter (Spearman’s rho=0.991, p=0.001) in non-tumorous lesions. Conclusion: 18F-FDOPA uptake of glioma was tumor specific with minimal effect of BBB breakage and associated with IDH mutation and histology. Further studies with a larger number of cases and molecular features such as LAT1 is needed to better understand the related mechanism of these clinicopathologic features and 18F-FDOPA uptake in glioma.