A pilot study of 4′-[methyl-11C]-thiothymidine PET/CT for detection of regional lymph node metastasis in non-small cell lung cancer

Abstract

Background4′-[methyl-11C]-thiothymidine (4DST) is a novel positron emission tomography (PET) tracer to assess proliferation of malignancy. The diagnostic abilities of 4DST and 2-deoxy-2-18 F-fluoro-d-glucose (FDG) for detecting regional lymph node (LN) metastases of non-small cell lung cancer (NSCLC) were prospectively compared. In addition, the relationship between the PET result and the patient's prognosis was evaluated.MethodsA total of 31 patients with NSCLC underwent 4DST PET/computed tomography (CT) and FDG PET/CT. The PET/CT images were evaluated qualitatively and quantitatively for focal uptake of each PET tracer, according to the staging system of the American Joint Committee on Cancer. Surgical and histological results provided the reference standards. Patients were followed for up to two years to assess disease-free survival.ResultsOn a per-lesion basis, sensitivity, specificity, positive predictive value, negative predictive value, and accuracy for LN staging were 82%, 72%, 32%, 96%, and 73%, respectively, for 4DST, and 29%, 86%, 25%, 88%, and 78%, respectively, for FDG. The sensitivity of 4DST was significantly higher than that of FDG (P < 0.001). The disease-free survival rate with positive 4DST uptake in nodal lesions was 0.35, which was considerably lower than the rate of 0.83 with negative findings (P = 0.04). Among the factors tested, nodal staging by 4DST was the most influential prognostic factor (P = 0.05) in predicting the presence of a previously existing spread lesion or of a recurrence over the course of 2 years.Conclusion4DST PET/CT is sensitive for detecting mediastinal lymph node metastasis in NSCLC, but its low specificity is a limitation. However, it may be helpful in predicting the prognosis of NSCLC.

A Pilot Study of 18F-Alfatide PET/CT Imaging for Detecting Lymph Node Metastases in Patients with Non-Small Cell Lung Cancer

“…Therefore, the researchers focused their attention on the development of new diagnostic methods and new tracers of PET for detecting LNMs in patients with NSCLC. 11 C-choline 25 , 18 F-fluorothymidine( 18 F-FLT) 26 , 4′-[methyl- 11 C]-thiothymidine(4DST) 27 , 18 F-Alfatide are all PET tracers used to visualize various malignancies and LNMs.…”

In vitro analysis of transport and metabolism of 4′-thiothymidine in human tumor cells

“…This would provide a more robust measure of DNA synthesis. While in vivo imaging studies demonstrate potential for 4DST in PET imaging [ 8 , 24 , 25 ], the longer scanning times needed for 4DST might limit its usefulness because of the relatively short half-life of the 11 C label.…”

Evaluation of DNA synthesis with carbon-11-labeled 4′-thiothymidine

“…The diagnostic ability of 11 C-4DST for detecting regional lymph node metastasis of non-small cell lung cancer (NSCLC) was prospectively evaluated by the same group (NCGM)[ 23 ]. A total of 31 patients with NSCLC underwent 11 C-4DST PET/CT and 18 F-FDG PET/CT.…”