Quickly predicting chemotherapy response to paclitaxel-based therapy in non-small cell lung cancer by early technetium-99m methoxyisobutylisonitrile chest single-photon-emission computed tomography

The purpose of this study was to retrospectively predict the chemotherapy r esponse to paclitaxel in non-small cell lung cancer (NSCLC) using technetiu m-99m methoxyisobutylisonitrile (Tc-99m MIBI) chest single-photon-emission computed tomography (SPECT) to detect the expression of multidrug-resistanc e-mediated M-r 170,000 P-glycoprotein, Before chemotherapy with Paclitaxel (Taxol), 30 patients with stage IIIb or TV NSCLC were enrolled in this stud y. Early chest SPECT 10 min after i.v. injection of Tc-99m MIBI was perform ed to qualitatively interpret Tc-99m MIBI chest SPECT visually and quantita tively calculate early tumor:normal lung ratios (T:NL) for quick assessment of multidrug-resistant P-glycoprotein expression in NSCLC. On the basis of qualitatively visual interpretation of early Tc-99m MIBI chest SPECT, all of 15 (100%) cases with good response to chemotherapy with Taxol could be d etected but 10 (67%) of 15 cases with poor response could not be detected. Early Tc-99m MIBI chest SPECT could correctly predict chemotherapy response in 25 (83%) of 30 of cases. The early T:NL were 3.30 +/- 0.82 for 15 patie nts with good response and 2.02 +/- 0.19 for 5 patients with poor response. The differences were significant (P < 0.05) by independent Student t tests . However, no significant differences were found for other prognostic facto rs (age, sex, tumor size, tumor location, stage, and cell type) between goo d-response and poor-response patients. Early Tc-99m MIBI chest SPECT has th e potential to predict chemotherapy response to Paclitaxel.