Value of brain 18F-FDG PET/CT in the preoperative localization of epileptogenic foci in refractory epilepsy patients with negative MRI / 中华核医学与分子影像杂志

ABSTRACT

Objective:To evaluate the value of 18F-FDG PET/CT for preoperative localization of epileptogenic foci in refractory epilepsy patients with negative MRI. Methods:Clinical data (550 lobes) of 55 epilepsy patients (38 males, 17 females, age (20.0±8.1) years) with negative MRI who underwent preoperative 18F-FDG PET/CT-MRI between January 2014 and June 2020 at the First Affiliated Hospital of Jinan University were retrospectively analyzed. The sensitivity, specificity, accuracy, positive predictive value (PPV) and negative predictive value (NPV) of 18F-FDG PET/CT, video electroencephalogram (VEEG), PET/CT+ VEEG and PET/CT-VEEG for localizing epileptogenic foci were calculated using stereoelectroencephalography (SEEG) and the outcomes of at least 1 year of postoperative follow-up as reference standards. χ2 test was used to compare the efficiencies of different examination modalities for unilobar, multilobar and all patients. Results:The correct lateralization rate of epileptogenic foci was 92.6%(25/27) using PET/CT. The sensitivity, specificity, accuracy, PPV and NPV of PET/CT for localization of epileptogenic foci were 65.1%(54/83), 77.9%(364/467), 76.0%(418/550), 34.4%(54/157) and 92.6%(364/393), respectively. The sensitivities of PET/CT-VEEG for localization of epileptogenic foci in all patients and patients with multilobar epilepsy were higher than those of VEEG alone (75.9%(63/83) vs 45.8%(38/83), 68.6%(35/51) vs 31.4%(16/51); χ2 values: 15.80, 14.16, both P<0.001). The specificities of PET/CT+ VEEG for localization of epileptogenic foci in all patients and patients with unilobar epilepsy were higher than those of VEEG alone (97.6%(456/467) vs 94.6%(442/467), 97.9%(282/288) vs 94.1%(271/288); χ2 values: 5.66, 5.48; P values: 0.017, 0.019). The sensitivity of PET/CT-VEEG (PET/CT and VEEG concordance) for localization of epileptogenic foci was higher than that of PET/CT+ VEEG (PET/CT and VEEG discordance) (8/9 vs 28.4%(21/74); χ2=10.40, P=0.001), and its specificity and accuracy were higher than those of PET/CT-VEEG (PET/CT and VEEG discordance) (93.4%(57/61) vs 71.7%(291/406), 92.9%(65/70) vs 72.1%(346/480); χ2 values: 13.23, 13.96; both P<0.001). Conclusions:18F-FDG PET/CT can localize and lateralize epileptogenic foci in patients with negative MRI. The combination of 18F-FDG PET/CT and VEEG improves the sensitivity, specificity, and accuracy for epileptogenic foci detection. 18F-FDG PET/CT is more accurate in detecting epileptogenic foci when it is concordant with VEEG.