[Correlation between 99m Tc-tetrofosmin uptake and P-glycoprotein expression in non-small-cell lung cancer].
We used thoracic SPECT to study the 99mTc-tetrofosmin (TF) uptake in patients with non-small-cell-lung-carcinoma (NSCLC). The results were compared with the percentage of P-glycoprotein (Pgp) found in flow cytometric analysis (FC) of samples of surgically-resected tumor tissue.


METHODS
A total of 21 patients with NSCLC were studied by means 99mTC-TF and thoracic SPECT. Image analysis included the determination of the TF uptake rate in the lung mass with respect to that of healthy tissue of the contralateral lung. These rates were compared with the percentage of Pgp expression according to FC. FC analysis was also carried out in 16 samples of healthy lung tissue obtained from the patients.


RESULTS
In healthy lung tissue, the mean Pgp expression according to FC was 4.58 +/- 1.87%. The cutoff value used to differentiate between Pgp positive and Pgp negative tumors was considered to be the mean plus two standard deviations (8.32). The Pgp-positive tumors (> 8.32%) presented significantly lower uptake levels (1.28 +/- 0.39) than the Pgp-negative lesions (1.66 +/- 0.33) (p = 0.029).


CONCLUSIONS
There is a inverse correlation between the Pgp expression as determined by FC analysis and 99mTc-TF in NSCLC. Thus, this radiopharmaceutical provides rapid and non-invasive information on Pgp expression in these lesions.
Tabuenca
M J
MJ
Servicio de Medicina Nuclear, Clínica Puerta de Hierro, Madrid, Madrid, 28035, España.
Vargas
J A
JA
Varela
A
A
Salas
C
C
Durántez
A
A
Ortiz Berrocal
J
J
D020168:ATP Binding Cassette Transporter, Subfamily B, Member 1 / Q000378:metabolism*; D000230:Adenocarcinoma / Q000000981:diagnostic imaging / Q000378:metabolism; D000328:Adult; D000368:Aged; D018196:Carcinoma, Adenosquamous / Q000000981:diagnostic imaging / Q000378:metabolism; D002289:Carcinoma, Non-Small-Cell Lung / Q000000981:diagnostic imaging* / Q000378:metabolism; D002294:Carcinoma, Squamous Cell / Q000000981:diagnostic imaging / Q000378:metabolism; D018432:Drug Resistance, Multiple; D019008:Drug Resistance, Neoplasm; D005260:Female; D005434:Flow Cytometry; D006801:Humans; D008168:Lung / Q000000981:diagnostic imaging / Q000378:metabolism; D008175:Lung Neoplasms / Q000000981:diagnostic imaging* / Q000378:metabolism; D008297:Male; D008875:Middle Aged; D009363:Neoplasm Proteins / Q000378:metabolism*; D009943:Organophosphorus Compounds / Q000493:pharmacokinetics*; D015609:Organotechnetium Compounds / Q000493:pharmacokinetics*; D019275:Radiopharmaceuticals / Q000493:pharmacokinetics*; D015899:Tomography, Emission-Computed, Single-Photon
D020168:ATP Binding Cassette Transporter, Subfamily B, Member 1; D009363:Neoplasm Proteins; D009943:Organophosphorus Compounds; D015609:Organotechnetium Compounds; D019275:Radiopharmaceuticals; C078700:technetium tc-99m tetrofosmin
Correlación entre la captación de 99m Tc-tetrofosmín y la expresión de P-glicoproteína en cáncer de pulmón no microcítico.