Predicting chemotherapy response and comparing with P-glycoprotein expression using technetium-99m tetrofosmin scan in untreated malignant lymphomas

The purposes of this study were to predict the chemotherapy response of unt reated malignant lymphomas (ML) using a technetium-99m tetrofosmin (Tc-TF) scan and to compare Tc-TF results with P-glycoprotein (Pgp) expression. Bef ore undergoing chemotherapy, 25 patients with ML were enrolled in this stud y. Tc-TF scan was performed 10 min after intravenous injection of Tc-TF. Im munohistochemical analyses were performed on multiple sections of ML specim ens to evaluate Pgp expression. The chemotherapy response was evaluated in the first 1-2 years after the completion of treatment. The mean tumor-to-ba ckground ratio of the 15 patients with good responses (3.23 +/- 0.56) was s ignificantly higher than that of the ten patients with poor responses (1.18 +/- 0.11). All of the 15 patients with good responses had positive Tc-TF s can results, but negative Pgp expression. Among the ten patients with poor responses, all had negative Tc-TF scan results, but six had positive Pgp ex pression and four had negative Pgp expression. Significant differences in t he incidences of good and poor responses were found between patients with p ositive Tc-TF scan results and patients with negative Tc-TF scan results an d between patients with positive Pgp expression and patients with negative Pgp expression. No significant differences in the incidences of good and po or responses were found between Hodgkin's disease patients and non-Hodgkin' s lymphoma patients, stage I-H patients and III-IV patients, patients aged > 40 and patients aged less than or equal to 40 years, and patients with an d without B symptoms. Compared with other prognostic factors, Tc-TF scan re sults and Pgp expression more accurately predict the chemotherapy response in patients with ML. (C) 2001 Elsevier Science Ireland Ltd. All rights rese rved.