RT Journal Article
SR Electronic
T1 Imaging Proliferation in Lung Tumors with PET: <sup>18</sup>F-FLT Versus <sup>18</sup>F-FDG
JF Journal of Nuclear Medicine
JO J Nucl Med
FD Society of Nuclear Medicine
SP 1426
OP 1431
VO 44
IS 9
A1 Buck, Andreas K.
A1 Halter, Gisela
A1 Schirrmeister, Holger
A1 Kotzerke, Jörg
A1 Wurziger, Imke
A1 Glatting, Gerhard
A1 Mattfeldt, Torsten
A1 Neumaier, Bernd
A1 Reske, Sven N.
A1 Hetzel, Martin
YR 2003
UL http://jnm.snmjournals.org/content/44/9/1426.abstract
AB Recently, the thymidine analog 3′-deoxy-3′-18F-fluorothymidine (FLT) was suggested for imaging tumoral proliferation. In this prospective study, we examined whether 18F-FLT better determines proliferative activity in newly diagnosed lung nodules than does 18F-FDG. Methods: Twenty-six patients with pulmonary nodules on chest CT were examined with PET and the tracers 18F-FDG and 18F-FLT. Tumoral uptake was determined by calculation of standardized uptake value (SUV). Within 2 wk, patients underwent resective surgery or had core biopsy. Proliferative activity was estimated by counting nuclei stained with the Ki-67–specific monoclonal antibody MIB-1 per total number of nuclei in representative tissue specimens. The correlation between the percentage of proliferating cells and the SUVs for 18F-FLT and 18F-FDG was determined using linear regression analysis. Results: Eighteen patients had malignant tumors (13 with non–small cell lung cancer [NSCLC], 1 with small cell lung cancer, and 4 with pulmonary metastases from extrapulmonary tumors); 8 had benign lesions. In all visible lesions, mean 18F-FDG uptake was 4.1 (median, 4.4; SD, 3.0; range, 1.0–10.6), and mean 18F-FLT uptake was 1.8 (median, 1.2; SD, 2.0; range, 0.8–6.4). Statistical analysis revealed a significantly higher uptake of 18F-FDG than of 18F-FLT (Mann–Whitney U test, P &lt; 0.05). 18F-FLT SUV correlated better with proliferation index (P &lt; 0.0001; r = 0.92) than did 18F-FDG SUV (P &lt; 0.001; r = 0.59). With the exception of 1 carcinoma in situ, all malignant tumors showed increased 18F-FDG PET uptake. 18F-FLT PET was false-negative in the carcinoma in situ, in another NSCLC with a low proliferation index, and in a patient with lung metastases from colorectal cancer. Increased 18F-FLT uptake was related exclusively to malignant tumors. By contrast, 18F-FDG PET was false-positive in 4 of 8 patients with benign lesions. Conclusion: 18F-FLT uptake correlates better with proliferation of lung tumors than does uptake of 18F-FDG and might be more useful as a selective biomarker for tumor proliferation.