RT Journal Article
SR Electronic
T1 Differential 18F-FDG and 18F-FLT Uptake on Serial PET/CT Imaging Before and During Definitive Chemoradiation for Non–Small Cell Lung Cancer
JF Journal of Nuclear Medicine
JO J Nucl Med
FD Society of Nuclear Medicine
SP 1069
OP 1074
DO 10.2967/jnumed.113.131631
VO 55
IS 7
A1 Sarah J. Everitt
A1 David L. Ball
A1 Rodney J. Hicks
A1 Jason Callahan
A1 Nikki Plumridge
A1 Marnie Collins
A1 Alan Herschtal
A1 David Binns
A1 Tomas Kron
A1 Michal Schneider
A1 Michael MacManus
YR 2014
UL http://jnm.snmjournals.org/content/55/7/1069.abstract
AB We aimed to prospectively observe cellular metabolism and proliferation in patients with non–small-cell lung cancer (NSCLC) during radical chemoradiation therapy using serial PET/CT with 18F-FDG and 3′-deoxy-3′-18F-fluorothymidine (18F-FLT). Methods: Twenty patients with stage I–III NSCLC and candidates for radical chemoradiation therapy (60 Gy in 30 fractions over 6 wk) were recruited. 18F-FDG and 18F-FLT PET/CT were performed at baseline and during therapy (weeks 2 and 4). Tumor response was assessed semiquantitatively and using visual response criteria. Results: The median and range for primary tumor volume (cm3) at baseline on 18F-FDG were 28 and 2–241, respectively, and on 18F-FLT 31 and 2–184, respectively. At week 2, 18F-FDG was 26 (range, 2–164), and 18F-FLT was 11 (range, 0–111). At week 4, 18F-FDG was 19 (1–147), and 18F-FLT was 7 (0–48). The median and range of maximum standardized uptake value (SUVmax) at baseline on 18F-FDG were 14 and 4–31, respectively, and on 18F-FLT 6 and 2–12, respectively. Week 2 18F-FDG median SUVmax was 10 (2–31), and 18F-FLT median SUVmax was 3 (1–15); week 4 18F-FDG median SUVmax was 10 (2–15), and 18F-FLT median SUVmax was 2 (2–9). There was fair agreement between visual tumor response on 18F-FDG and 18F-FLT during therapy (Cohen's unweighted κ statistic, 0.27 at week 2 and 0.355 at week 4). Cerebral metastases were detected on 1 baseline 18F-FLT scan, resulting in palliative management. Progressive disease was detected on week 2 scans in 3 patients, resulting in changes to radiation therapy (2 patients) and treatment intent (1 patient). Conclusion: This study demonstrates that 18F-FLT PET/CT is a more sensitive tracer of early treatment response than 18F-FDG PET/CT. The ability of these tracers to detect distinct biologic processes may lead to their use as biomarkers for personalized radiation therapy and prognosis in the future.