Using dielectric spectroscopy as a diagnostic test to differentiate benign and malignant serous effusions

Centrifuged serous effusions obtained from the peritoneal and pleural cavities of different patients were characterized by dielectric spectroscopy at radio frequency. Results showed that benign serous effusions exhibit similar dielectric behavior to sucrose-added pure water. The malignant serous effusions showed a different characteristic, especially in the 104–105 rad/s angular frequency region. The observed relaxation behaviors were attributed to the polarization of macromolecule and protein contents at frequencies over 105 rad/s. The relaxations under the angular frequency of 104 rad/s were attributed to macromolecule- and proteins-bound water, etc. In light of these results, it was thought that dielectric spectroscopy, which is an efficient characterization technique for such solids as inorganic and polymeric materials to analyze their capacitive and structural behaviors, may be suggested as a rapid in vitro diagnostic method in determining the distinction between benign and malignant serous effusions.