Analysis and reproducibility of 3'-Deoxy-3'-[18F]fluorothymidine positron emission tomography imaging in patients with non-small cell lung cancer.
OBJECTIVE
Imaging tumor proliferation with 3'-deoxy-3'-[(18)F]fluorothymidine (FLT) and positron emission tomography is being developed with the goal of monitoring antineoplastic therapy. This study assessed the methods to measure FLT retention in patients with non-small cell lung cancer (NSCLC) to measure the reproducibility of this approach.


METHODS
Nine patients with NSCLC who were untreated or had progressed after previous therapy were imaged twice using FLT and positron emission tomography within 2 to 7 days. Reproducibility (that is, error) was measured as the percent difference between the two patient scans. Dynamic imaging was obtained during the first 60 min after injection. Activity in the blood was assessed from aortic images and the fraction of unmetabolized FLT was measured. Regions of interest were drawn on the plane with the highest activity and the adjacent planes to measure standardized uptake value (SUV(mean)) and kinetic variables of FLT flux.


RESULTS
We found that the SUV(mean) obtained from 30 to 60 min had a mean error of 3.6% (range, 0.6-6.9%; SD, 2.3%) and the first and second scans were highly correlated (r(2) = 0.99; P < 0.0001). Using shorter imaging times from 25 to 30 min or from 55 to 60 min postinjection also resulted in small error rates; SUV(mean) mean errors were 8.4% and 5.7%, respectively. Compartmental and graphical kinetic analyses were also fairly reproducible (r(2) = 0.59; P = 0.0152 and r(2) = 0.58; P = 0.0175 respectively).


CONCLUSIONS
FLT imaging of patients with NSCLC was quite reproducible with a worst case SUV(mean) error of 21% when using a short imaging time.
Shields
Anthony F
AF
Department of Internal Medicine, Wayne State University, Detroit, Michigan 48201-2013, USA. ShieldsA@Karmanos.org
Lawhorn-Crews
Jawana M
JM
Briston
David A
DA
Zalzala
Sajad
S
Gadgeel
Shirish
S
Douglas
Kirk A
KA
Mangner
Thomas J
TJ
Heilbrun
Lance K
LK
Muzik
Otto
O
D000368:Aged; D002289:Carcinoma, Non-Small-Cell Lung / Q000000981:diagnostic imaging*; D015224:Dideoxynucleosides / Q000493:pharmacokinetics; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008175:Lung Neoplasms / Q000000981:diagnostic imaging*; D008297:Male; D008875:Middle Aged; D049268:Positron-Emission Tomography / Q000379:methods*; D019275:Radiopharmaceuticals / Q000493:pharmacokinetics; D015203:Reproducibility of Results
D015224:Dideoxynucleosides; D019275:Radiopharmaceuticals; C002854:alovudine