Imaging Proliferation in Brain Tumors with 18F-FLT PET: Comparison with 18F-FDG

Journal of Nuclear Medicine

Michael E. Phelps¹  Johannes Czernin¹  Marvin Bergsneider¹  Nirav Kamdar¹  Nagichettiar Satyamurthy¹  Wei Chen¹  Paul Mischel¹  Daniel H.S. Silverman¹  Timothy Cloughesy¹  Linda Liau¹ 

关键词: ¹⁸F-FLT;    ¹⁸F-FDG;    Ki-67;    proliferation;    brain tumor;   

DOI  :  

学科分类：医学（综合）

来源: Society of Nuclear Medicine

【 摘 要 】

3′-Deoxy-3′-18F-fluorothymidine (18F-FLT) is a recently developed PET tracer to image tumor cell proliferation. We characterized 18F-FLT PET of brain gliomas and compared 18F-FLT with 18F-FDG PET in side-by-side studies of the same patients. Methods: Twenty-five patients with newly diagnosed or previously treated glioma underwent PET with 18F-FLT and 18F-FDG on consecutive days. Three stable patients in long-term remission were included as negative control subjects. Tracer kinetics in normal brain and tumor were measured. Uptake of 18F-FLT and 18F-FDG was quantified by the standardized uptake value (SUV) and the tumor-to-normal tissue (T/N) ratio. The accuracy of 18F-FLT and 18F-FDG PET in evaluating newly diagnosed and recurrent gliomas was compared. More than half of the patients underwent resection after the PET study and correlations between PET uptake and the Ki-67 proliferation index were examined. Patients were monitored for a mean of 15.4 mo (range, 12–20 mo). The predictive power of PET for tumor progression and survival was analyzed using Kaplan–Meier statistics. Results: 18F-FLT uptake in tumors was rapid, peaking at 5–10 min after injection and remaining stable up to 75 min. Hence, a 30-min scan beginning at 5 min after injection was sufficient for imaging. 18F-FLT visualized all high-grade (grade III or IV) tumors. Grade II tumor did not show appreciable 18F-FLT uptake and neither did the stable lesions. The absolute uptake of 18F-FLT was low (maximum-pixel SUV [SUVmax], 1.33) but image contrast was better than with 18F-FDG (T/N ratio, 3.85 vs. 1.49). 18F-FDG PET studies were negative in 5 patients with recurrent high-grade glioma who subsequently suffered tumor progression within 1–3 mo. 18F-FLT SUVmax correlated more strongly with Ki-67 index (r = 0.84; P < 0.0001) than 18F-FDG SUVmax (r = 0.51; P = 0.07). 18F-FLT uptake also had more significant predictive power with respect to tumor progression and survival (P = 0.0005 and P = 0.001, respectively). Conclusion: Thirty-minute 18F-FLT PET 5 min after injection was more sensitive than 18F-FDG to image recurrent high-grade tumors, correlated better with Ki-67 values, and was a more powerful predictor of tumor progression and survival. Thus, 18F-FLT appears to be a promising tracer as a surrogate marker of proliferation in high-grade gliomas.

【 授权许可】

Unknown