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 Technetium-99m (Tc-99m) tetrofosmin accumulation in tumors which may represent the expression of multidrug resistance (MDR)--mediated P-glycoprotein (Pgp) and multidrug resistance-associated protein (MRP) as well as response to chemotherapy 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 interpreted both visually and quantitatively. Response was evaluated upon completion of chemotherapy. Patients with good chemotherapy response had a significantly higher incidence (93%) of positive Tc-99m tetrofosmin lung single photon 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, respectively (p < 0.05). However, other prognostic factors (tumor size and stage) were not significantly related to Tc-99m tetrofosmin lung scan findings and chemotherapy responses. Tc-99m tetrofosmin lung scintigraphy can predict chemotherapy response in patients with SCLC.