[18F]Fluorothymidine positron emission tomography before and 7 days after gefitinib treatment predicts response in patients with advanced adenocarcinoma of the lung.
OBJECTIVE
To evaluate the usefulness of 3'-deoxy-3'-[18F]fluorothymidine (FLT)-positron emission tomography (PET) for predicting response and patient outcome of gefitinib therapy in patients with adenocarcinoma of the lung.


METHODS
Nonsmokers with advanced or recurrent adenocarcinoma of the lung were eligible. FLT-PET images of the thorax were obtained before and 7 days after the start of gefitinib (250 mg/d) therapy, the maximum standardized uptake values (SUVmax) of primary tumors were measured, and the percent changes in SUVmax were calculated. After 6 weeks of therapy, the responses were assessed by computed tomography of the chest.


RESULTS
Among 31 patients who were enrolled, we analyzed 28 patients for whom we had complete data. Chest computed tomography revealed partial response in 14 (50%), stable disease in 4 (14%), and progressive disease in 10 (36%) after 6 weeks of treatment. Pretreatment SUVmax of the tumors did not differ between responders and nonresponders. At 7 days after the initiation of therapy, the percent changes in SUVmax were significantly different (-36.0 +/- 15.4% versus 10.1 +/- 19.5%; P < 0.001). Decrease of > 10.9% in SUVmax was used as the criterion for predicting response. The positive and negative predictive values were both 92.9%. The time to progression was significantly longer in FLT-PET responders than nonresponders (median, 7.9 versus 1.2 months; P = 0.0041).


CONCLUSIONS
FLT-PET can predict response to gefitinib 7 days after treatment in nonsmokers with advanced adenocarcinoma of the lung. The change in tumor SUVmax obtained by FLT-PET seems to be a promising predictive variable.
Sohn
Hee-Jung
HJ
Division of Oncology, University of Ulsan College of Medicine, Asan Medical Center, Seoul, Korea.
Yang
You-Jung
YJ
Ryu
Jin-Sook
JS
Oh
Seung Jun
SJ
Im
Ki Chun
KC
Moon
Dae Hyuk
DH
Lee
Dae Ho
DH
Suh
Cheolwon
C
Lee
Jung-Shin
JS
Kim
Sang-We
SW
D000230:Adenocarcinoma / Q000000981:diagnostic imaging* / Q000188:drug therapy / Q000473:pathology; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000970:Antineoplastic Agents / Q000627:therapeutic use*; D005260:Female; D005462:Fluorine Radioisotopes; D000077156:Gefitinib; D006801:Humans; D053208:Kaplan-Meier Estimate; D008175:Lung Neoplasms / Q000000981:diagnostic imaging* / Q000188:drug therapy / Q000473:pathology; D008297:Male; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local / Q000188:drug therapy / Q000473:pathology; D049268:Positron-Emission Tomography; D011379:Prognosis; D011799:Quinazolines / Q000627:therapeutic use*; D012372:ROC Curve; D019275:Radiopharmaceuticals; D013936:Thymidine; D013995:Time; D014057:Tomography, X-Ray Computed
D000970:Antineoplastic Agents; D005462:Fluorine Radioisotopes; D011799:Quinazolines; D019275:Radiopharmaceuticals; D000077156:Gefitinib; D013936:Thymidine