Animal-Based Model to Investigate the Minimum Tumor Size Detectable with an Electrical Impedance Scanning Technique

Malich, Ansgar; Böhm, Thomas; Fritsch, Tobias; Facius, Mirjam; Freesmeyer, Martin G.; Anderson, Roselle; Fleck, Marlies; Kaiser, Werner A.

doi:10.1016/S1076-6332(03)80786-9

« Previous Next »Academic Radiology
Volume 10, Issue 1 , Pages 37-44, January 2003

Animal-Based Model to Investigate the Minimum Tumor Size Detectable with an Electrical Impedance Scanning Technique

Ansgar Malich, MD
- Institute of Diagnostic and Interventional Radiology, Friedrich-Schiller University Jena, Bachstrasse 18, 07740 Jena, Germany
- Institute of Diagnostic and Interventional Radiology, Friedrich-Schiller University Jena, Bachstrasse 18, 07740 Jena, Germany
Thomas Böhm, MD
- Institute of Diagnostic Radiology, University of Zurich, Switzerland
Tobias Fritsch, MD
- Institute of Diagnostic and Interventional Radiology, Friedrich-Schiller University Jena, Bachstrasse 18, 07740 Jena, Germany
Mirjam Facius, MD
- Institute of Diagnostic and Interventional Radiology, Friedrich-Schiller University Jena, Bachstrasse 18, 07740 Jena, Germany
Martin G. Freesmeyer, MD
- Institute of Diagnostic and Interventional Radiology, Friedrich-Schiller University Jena, Bachstrasse 18, 07740 Jena, Germany
Roselle Anderson
- Department of Special Systems-Women's Health, Siemens-Elema AB, Solna, Sweden
Marlies Fleck, MD
- Institute of Diagnostic and Interventional Radiology, Friedrich-Schiller University Jena, Bachstrasse 18, 07740 Jena, Germany
Werner A. Kaiser, MD
- Institute of Diagnostic and Interventional Radiology, Friedrich-Schiller University Jena, Bachstrasse 18, 07740 Jena, Germany

Received 15 July 2002; received in revised form 23 August 2002; accepted 26 August 2002.

Abstract

Rationale and Objectives

The purpose of this study was to determine the minimum tumor size detectable with electrical impedance scanning (EIS) in laboratory animals.

Materials and Methods

VX2 tumor cells (1 mm³) were implanted bilaterally into the upper leg musculature of five white New Zealand rabbits. EIS and ultrasound (US) were performed before, during, and immediately after implantation and on every 2nd day thereafter until tumors could be visualized with both modalities. This was followed by an extended follow-up regimen until a tumor size of 1 cm³ was reached. Rabbits were anesthetized subcutaneously.

Results

Tumors could not be implanted in one rabbit. Neither EIS nor US were performed in one rabbit due to severe skin alterations at the implantation site. No focal increase in conductance was visible before or immediately after tumor injection. The smallest tumor identified with EIS was determined with US to be approximately 8 mm³. The mean tumor size at initial detection was 52 mm³ (determined with EIS). In two cases, the tumor was first seen with US (EIS detection was delayed with a delay of 1 and 2 days, respectively). In all remaining cases, tumors were detected simultaneously with both EIS and US. All tumors were visible with EIS.

Conclusion

The animal-based model is feasible. VX2 tumors are detectable with EIS. Tumors characterized by a focal spot at EIS could be detected starting at a tumor size of 7.5 mm³.

Keywords: Breast neoplasms