Abstract P4-03-02: Mapping breast tissue types by miniature radio-frequency near-field spectroscopy sensor

Abstract

Background: The study goal was to test the ability of a miniature flexible RF sensor (Dune Medical Devices), designed to be mounted on the surface of surgical tools, in measuring and mapping the various breast tissue types in terms of electrical properties. This study was part of the first stage in developing a measuring device for use during biopsy procedures. Methods: One hundred and two (102) patients undergoing lumpectomy, open biopsy or mastectomy in 3 medical centers between January and October 2012 were enrolled in this study. The device was applied to numerous sites of freshly excised specimens. Measurement sites were accurately marked, to ensure registration between device measurement and histology analysis. The dielectric properties of the various tissue types were derived from matching between measurements and histology. The correlation between device readings and tissue type, as well as the ability of the device to differentiate between malignant and non-malignant sites, was assessed. Results: A total of 4322 measurements from 102 patients were analyzed. The dielectric properties of 10 tissue types in the low RF frequency (4-30MHz) range were measured, showing distinct differences between the various types. The correlation between the RF measurements, as quantified by a score variable, and the tissue types, is demonstrated, with a correlation coefficient of 0.90 (95% CI: 0.89 - 0.91). Differentiation ability between tissue types is also demonstrated using ROC curve analysis, with AUG of 0.96 (95% CI: 0.95 - 0.97), and sensitivity and specificity of 90.2% (95% CI: 84 - 95) and 90.9% (95% CI: 90 - 92), respectively, at feature sizes at or above 0.8 mm in diameter. Conclusions: First results from a radio-frequency near-field spectroscopy miniature flexible sensor evaluate the dielectric properties of various breast tissue types. The results also show promise in differentiating between various breast tissue types, and specifically for differentiation between cancer and normal tissues. The sensor's dimensions (radius of ∼1mm) and flexible design enable use in lumpectomy procedures (for margin assessment) as well as in minimally invasive devices and breast biopsy. Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr P4-03-02.