Comparison of11C-CHOLINE (11C-CHO)and 18F-FDG PET/CT brain imaging in the differentiationof benign from malignant lesions in patients with enhancement on brain MRI.

Purpose: Glioma is an invasive growth tumor that is difficult to resect completely. Accurate diagnosis of residual or recurrent disease post surgery is of great value for the selection of the postoperative treatments, evaluation of efficacy and prognosis. The purpose of this investigation was to assess the value of 11C-CHO and 18F-FDG PET/CT brain imaging in the differential diagnoses of contrast enhanced lesions shown on brain MRI.

Methods: Thirty patients who had ring-shape enhanced intracerebral lesions on the MRI images in our hospital (17 males, 13 females, mean age: 61.23±8.00 years) underwent both 18F-FDG and 11C-CHO PET/ CT brain imaging. The results were analyzed in visually and semi-quantitatively. The final diagnoses were compared to surgical results and follow-up.

Results: A total of 32 lesions were found on the 18F-FDG PET/CT images, We correctly diagnosed 14 cases of malignant lesions based on FDG PET/CT images. However, there were 5 cases of false negatives and 4 cases of false positives on 18F-FDG PET/CT brain scan. And the sensitivity, specificity and accuracy of 18F-FDG were 73.7%, 63.6% and 70.0%, respectively. In comparison, a total of 38 lesions showed on the 11C-CHO PET/CT images. We correctly identified 19 cases of malignant lesions based on 11C-CHO PET/CT images. There were 2 cases of false negatives and 1 case of false positive on 11C-CHO PET/CT scan.Meanwhile, the sensitivity, specificity and accuracy of 11C-CHO PET/CT brain imaging were 90.5%, 88.9% and 90.0%, respectively.

Conclusions: Although both 18F-FDG and 11C-CHO PET/CT have value in the evaluation of ring-enhanced brain tumors shown on MRI, 11C-CHO PET/CT is more accurate. A combined use of the both tracers can improve the accuracy of the diagnosis of ring-enhanced lesions on brain MRI.