Assessment of Simplified Methods to Measure sigma up 18 Theta -FLT Uptake Changes in EGFR-Mutated Non-Small Cell Lung Cancer Patients Undergoing EGFR Tyrosine Kinase Inhibitor Treatment

• Published in: The Journal of nuclear medicine (1978) Vol. 55; no. 9; p. 1417
• Main Authors: Frings, Virginie, Yaqub, Maqsood, Hoyng, Lieke L, Golla, Sandeep SV, Windhorst, Albert D, Schuit, Robert C, Lammertsma, Adriaan A, Hoekstra, Otto S, Smit, Egbert F, Boellaard, Ronald
• Format: Journal Article
• Language: English
• Published: 01-09-2014
• ISSN: 0161-5505

3'-deoxy-3'-...F-fluorothymidine (...F-FLT) PET/CT provides a noninvasive assessment of proliferation and, as such, could be a valuable imaging biomarker in oncology. The aim of the present study was to assess the validity of simplified quantitative parameters of ...F-FLT uptake in non-small cell lung cancer (NSCLC) patients before and after the start of treatment with a tyrosine kinase inhibitor (TKI). Ten patients with metastatic NSCLC harboring an activating epidermal growth factor receptor mutation were included in this prospective observational study. Patients underwent ...O-H...O and ...F-FLT PET/CT scanning on 3 separate occasions: within 7 d before treatment, and 7 and 28 d after the first therapeutic dose of a TKI (gefitinib or erlotinib). Dynamic scans were acquired and venous blood samples were collected during the ...F-FLT scan to measure parent fraction and plasma and whole-blood radioactivity concentrations. Simplified measures (standardized uptake value [SUV] and tumor-to-blood ratio [TBR]) were correlated with fully quantitative measures derived from kinetic modeling. Twenty-nine of thirty ...F-FLT PET/CT scans were evaluable. According to the Akaike criterion, a reversible 2-tissue model with 4 rate constants and blood volume parameter was preferred in 84% of cases. Relative therapy-induced changes in SUV and TBR correlated with those derived from kinetic analyses (r... = 0.83-0.97, P 0.001, slope = 0.72-1.12). ...F-FLT uptake significantly decreased at 7 and 28 d after the start of treatment compared with baseline (P 0.01). Changes in ...F-FLT uptake were not correlated with changes in perfusion, as measured using ...O-H...O. SUV and TBR could both be used as surrogate simplified measures to assess changes in ...F-FLT uptake in NSCLC patients treated with a TKI, at the cost of a small underestimation in uptake changes or the need for a blood sample and metabolite measurement, respectively. (ProQuest: ... denotes formulae/symbols omitted.)