Comparison of 4′-[methyl- 11C]thiothymidine ( 11C-4DST) and 3′-deoxy-3′-[ 18F]fluorothymidine ( 18F-FLT) PET/CT in human brain glioma imaging

摘要

Background 3′-deoxy-3′-[~(18)F]fluorothymidine (~(18)F-FLT) has been used to evaluate tumor malignancy and cell proliferation in human brain gliomas. However,~(18)F-FLT has several limitations in clinical use. Recently,~(11)C-labeled thymidine analogue, 4′-[methyl-~(11)C]thiothymidine (~(11)C-4DST), became available as an in vivo cell proliferation positron emission tomography (PET) tracer. The present study was conducted to evaluate the usefulness of~(11)C-4DST PET in the diagnosis of human brain gliomas by comparing with the images of~(18)F-FLT PET. Methods Twenty patients with primary and recurrent brain gliomas underwent~(18)F-FLT and~(11)C-4DST PET scans. The uptake values in the tumors were evaluated using the maximum standardized uptake value (SUVmax), the tumor-to-normal tissue uptake (T/N) ratio, and the tumor-to-blood uptake (T/B) ratio. These values were compared among different glioma grades. Correlation between the Ki-67 labeling index and the uptake values of~(11)C-4DST and~(18)F-FLT in the tumor was evaluated using linear regression analysis. The relationship between the individual~(18)F-FLT and~(11)C-4DST uptake values in the tumors was also examined. Results ~(11)C-4DST uptake was significantly higher than that of~(18)F-FLT in the normal brain. The uptake values of~(11)C-4DST in the tumor were similar to those of~(18)F-FLT resulting in better visualization with~(18)F-FLT. No significant differences in the uptake values of~(18)F-FLT and~(11)C-4DST were noted among different glioma grades. Linear regression analysis showed a significant correlation between the Ki-67 labeling index and the T/N ratio of~(11)C-4DST ( r ?=?0.50, P ?