Paclitaxel-based chemotherapy for non-small cell lung cancer: Predicting the response with Tc-99m-tetrofosmin chest imaging

The purpose of this study was to retrospectively predict the chemotherapeut ic response to pactitaxel for non-small cell lung cancer (NSCLC) using Tc-9 9m-tetrofosmin (TF) uptake and to detect the expression of 170-kDa multidru g resistance-mediated P-glycoprotein (MDR-Pgp). Methods: Before chemotherap y with paclitaxel, 20 patients with stage IIIb or IV NSCLC were enrolled in this study to undergo early and delayed Tc-99m-TF chest imaging for calcul ating tumor-to-normal lung ratios (T/NL) and retention indices (RI) for ass essment of the MDR-Pgp in NSCLC. Results: The early and delayed mean T/NLs were 1.59 +/- 0.25 and 1.50 +/- 0,25, respectively, for 10 patients with a good response and 1.09 +/- 0.09 and 1.03 +/- 0.05, respectively for 10 pati ents with a poor response. The differences were shown to be significant (P < 0.001) by independent Student t tests. However, no significant difference s (P = 0.801) between good-response patients (-5,70% +/- 3.67%) and poor-re sponse patients (-5.23% +/- 4,51 %) were found in RI. In addition, other pr ognostic factors (age, sex, tumor size, stage, and cell type) were not sign ificantly different between good-response patients and poor-response patien ts. Conclusion: (TC)-T-99m-TF chest images are potential tools for understa nding MDR-Pgp expression in NSCLC and for predicting the chemotherapeutic r esponse to paclitaxel.