TY - JOUR T1 - In Vivo Characterization of Proliferation for Discriminating Cancer from Pancreatic Pseudotumors JF - Journal of Nuclear Medicine JO - J Nucl Med SP - 1437 LP - 1444 DO - 10.2967/jnumed.108.052027 VL - 49 IS - 9 AU - Ken Herrmann AU - Florian Eckel AU - Stefan Schmidt AU - Klemens Scheidhauer AU - Bernd Joachim Krause AU - Joerg Kleeff AU - Tibor Schuster AU - Hans-Juergen Wester AU - Helmut Friess AU - Roland M. Schmid AU - Markus Schwaiger AU - Andreas K. Buck Y1 - 2008/09/01 UR - http://jnm.snmjournals.org/content/49/9/1437.abstract N2 - We have determined the ability of PET with the thymidine analog 3′-deoxy-3′-18F-fluorothymidine (FLT) to detect pancreatic cancer and to differentiate malignant from benign pancreatic lesions. Methods: In this prospective study, 18F-FLT PET was performed on 31 patients with undefined pancreatic lesions. Routine diagnostic procedures included endoscopic ultrasound, MRI, or multislice helical CT of the upper gastrointestinal tract in all patients. Uptake of 18F-FLT was evaluated semiquantitatively by calculation of mean and maximal standardized uptake values (SUVs). Results were correlated to the reference methods, which were histopathology (23/31) or cytology/clinical follow-up (8/31). Results: All 10 benign pancreatic lesions were negative on 18F-FLT PET and showed only background activity (specificity, 100%; 90% confidence interval, 74%−100%). On visual interpretation, 15 of 21 malignant tumors presented as focal 18F-FLT uptake higher than the surrounding background (sensitivity, 71.4%; 90% confidence interval, 52%−89%). 18F-FLT PET missed 4 well-differentiated and 2 T1 cancers. Mean 18F-FLT uptake was 3.1 in all malignant tumors (median, 2.8; range, 1.3–8.5), 3.7 in tumors with visual tracer uptake (median, 3.2; range, 2.1–8.5), and significantly higher in malignant than in benign tumors (mean/median, 1.4; range, 1.2–1.7; P < 0.001). For discriminating cancer from benign pancreatic lesions, receiver-operating-characteristic analysis indicated a sensitivity of 81% and specificity of 100% (area under the curve, 0.93) using a mean 18F-FLT SUV cutoff of 1.8 (maximal 18F-FLT SUV: area under the curve, 0.92; SUV cutoff, 2.1). Conclusion: In this pilot study, focal uptake of the in vivo proliferation marker 18F-FLT was detected exclusively in malignant tumors. 18F-FLT PET may therefore be useful as a diagnostic adjunct for differentiating cancer from benign pancreatic lesions. ER -