Evaluation of chemotherapy response in patients with small cell lung cancer using Technetium-99m-tetrofosmin

The aim of this study was to investigate the relationship between Technetiu m-99m (Tc-99m) tetrofosmin accumulation in tumors which may represent the e xpression of multidrug resistance (MDR) - mediated P-glycoprotein (Pgp) and multidrug resistance - associated protein (MRP) as well as response to che motherapy in patients with untreated small cell lung cancers (SCLC). Twenty patients with SCLC were studied with Tc-99m tetrofosmin lung scintigraphy before chemotherapeutic induction. Tc-99m tetrofosmin lung scans were inter preted both visually and quantitatively. Response was evaluated upon comple tion of chemotherapy. Patients with good chemotherapy response had a signif icantly higher incidence (93%) of positive Tc-99m tetrofosmin lung single p hoton emission computed tomography (SPECT) findings than patients with poor response (33%) (p value < 0.05) The tumor/background ratios (T/B) were 1.8 +/-0.4 and 1.2+/-0.3 for patients with good response and poor response, res pectively (p < 0.05). However, other prognostic factors (tumor size and sta ge) were not significantly related to Tc-99m tetrofosmin lung scan findings and chemotherapy responses. Tc-99m tetrofosmin lung scintigraphy can predi ct chemotherapy response in patients with SCLC.