Imaging Gastric Cancer with PET and the Radiotracers 18F-FLT and 18F-FDG: A Comparative Analysis

Journal of Nuclear Medicine

Tibor Schuster¹  Markus Schwaiger¹  Ken Herrmann¹  Andreas K. Buck¹  Bernd J. Krause¹  Hans-Jürgen Wester¹  Dirk Wilhelm¹  Florian Lordick¹  Michael Souvatzoglou¹  Katja Ott¹  Karen Becker¹  Jörg R. Siewert¹ 

关键词: FLT;    gastric cancer;    proliferation;    PET;   

DOI  :  10.2967/jnumed.107.044867

学科分类：医学（综合）

来源: Society of Nuclear Medicine

【 摘 要 】

In this pilot study, we evaluated 3′-deoxy-3′-18F-fluorothymidine (FLT) PET for the detection of gastric cancer and compared the diagnostic accuracy with that of 18F-FDG PET. Methods: Forty-five patients (31 male and 14 female) with histologically proven locally advanced gastric cancer underwent attenuation-corrected whole-body 18F-FLT PET and 18F-FDG PET/CT (low-dose CT). 18F-FLT emission images were acquired on a full-ring PET scanner 45 min after the injection of 270–340 MBq of 18F-FLT. 18F-FDG PET/CT was performed 60 min after the injection of 300–370 MBq of 18F-FDG. Mean standardized uptake values for 18F-FLT and 18F-FDG were calculated using circular ROIs (diameter, 1.5 cm) in the primary tumor manifestation site, in a reference segment of the liver, and in the bone marrow and were compared on a lesion-by-lesion basis. Results: According to the Lauren classification, 15 tumors (33%) were of the intestinal subtype and 30 (67%) of the nonintestinal subtype. 18F-FLT PET images showed high contrast for the primary tumor and proliferating bone marrow. In all patients (45/45), focal 18F-FLT uptake could be detected in the primary tumor. In contrast, 14 primary tumors were negative for 18F-FDG uptake, with lesional 18F-FDG uptake lower than or similar to background activity. The mean standardized uptake value for 18F-FLT in malignant primaries was 6.0 ± 2.5 (range, 2.4–12.7). In the subgroup of 18F-FDG–positive patients, the mean value for 18F-FDG was 8.4 ± 4.1 (range, 3.8/19.0), versus 6.8 ± 2.6 for 18F-FLT (Wilcoxon test: P = 0.03). Comparison of mean 18F-FLT and 18F-FDG uptake in tumors with signet ring cells revealed no statistically significant difference between the tracers (6.2 ± 2.1 for 18F-FLT vs. 6.4 ± 2.8 for 18F-FDG; Wilcoxon test: P = 0.94). Conclusion: The results of this study indicate that imaging gastric cancer with the proliferation marker 18F-FLT is feasible. 18F-FLT PET was more sensitive than 18F-FDG PET, especially in tumors frequently presenting without or with low 18F-FDG uptake, and may improve early evaluation of response to neoadjuvant treatment.

【 授权许可】

Unknown