Fluorine-18-alpha-methyltyrosine positron emission tomography for diagnosis and staging of lung cancer: a clinicopathologic study.
OBJECTIVE
L-[3-(18)F]-alpha-methyltyrosine ([(18)F]FMT) is an amino acid tracer for positron emission tomography (PET). We evaluated the diagnostic usefulness of [(18)F]FMT PET in non-small-cell lung cancer (NSCLC) patients. Tumor uptake of [(18)F]FMT was compared with that of 2-[(18)F]-fluoro-2-deoxy-D-glucose ([(18)F]FDG) and correlated with L-type amino acid transporter 1 (LAT1) expression.


METHODS
Fifty NSCLC patients were enrolled in this study, and a pair of PET study with [(18)F]FMT and [(18)F]FDG was done. LAT1 expression and Ki-67 labeling index of the resected tumors were analyzed by immunohistochemical staining.


RESULTS
For the primary tumor detection, [(18)F]FMT PET exhibited a sensitivity of 90% whereas the sensitivity for [(18)F]FDG PET was 94%. For lymph node staging, the sensitivity and specificity of [(18)F]FMT PET were 57.8% and 100%, and those of [(18)F]FDG PET were 65.7% and 91%, respectively. The expression of LAT1 in squamous cell carcinoma and large cell carcinoma was significantly higher than that in adenocarcinoma. [(18)F]FMT uptake was also higher in squamous cell carcinoma and large cell carcinoma than in adenocarcinoma. Uptake of [(18)F]FMT in the tumor is closely correlated with LAT1 expression (rho = 0.890).


CONCLUSIONS
[(18)F]FMT PET had no false-positives in the detection of primary tumor and lymph node metastasis and could improve the diagnostic performance in NSCLC. Uptake of [(18)F]FMT correlated with the expression of LAT1 that showed a significant association with cellular proliferation.
Kaira
Kyoichi
K
Department of Medicine and Molecular Science, Gunma University Graduate School of Medicine, Maebashi, Gunma, Japan. kkaira1970@yahoo.co.jp
Oriuchi
Noboru
N
Otani
Yoshimi
Y
Shimizu
Kimihiro
K
Tanaka
Shigebumi
S
Imai
Hisao
H
Yanagitani
Noriko
N
Sunaga
Noriaki
N
Hisada
Takeshi
T
Ishizuka
Tamotsu
T
Dobashi
Kunio
K
Kanai
Yoshikatsu
Y
Endou
Hitoshi
H
Nakajima
Takashi
T
Endo
Keigo
K
Mori
Masatomo
M
D000230:Adenocarcinoma / Q000378:metabolism / Q000473:pathology; D000328:Adult; D000368:Aged; D018287:Carcinoma, Large Cell / Q000175:diagnosis / Q000378:metabolism / Q000473:pathology; D002289:Carcinoma, Non-Small-Cell Lung / Q000175:diagnosis* / Q000473:pathology*; D005189:False Positive Reactions; D005260:Female; D005462:Fluorine Radioisotopes / Q000494:pharmacology*; D006801:Humans; D007150:Immunohistochemistry / Q000379:methods; D019394:Ki-67 Antigen / Q000096:biosynthesis; D027283:Large Neutral Amino Acid-Transporter 1 / Q000378:metabolism; D008175:Lung Neoplasms / Q000175:diagnosis* / Q000473:pathology*; D008207:Lymphatic Metastasis; D008297:Male; D008875:Middle Aged; D009367:Neoplasm Staging / Q000379:methods*; D049268:Positron-Emission Tomography / Q000379:methods*; D019275:Radiopharmaceuticals / Q000494:pharmacology*; D012680:Sensitivity and Specificity; D016896:Treatment Outcome
D005462:Fluorine Radioisotopes; D019394:Ki-67 Antigen; D027283:Large Neutral Amino Acid-Transporter 1; D019275:Radiopharmaceuticals