A microwave super-resolution imaging approach towards breast cancer margin mapping

TL;DR

This paper introduces a microwave imaging method for real-time intraoperative breast cancer margin assessment, achieving high-resolution tissue hydration mapping and identifying inadequate margins during surgery.

Contribution

A novel microwave single pixel imaging technique for intraoperative margin detection with deep sub-wavelength resolution and tissue discrimination capabilities.

Findings

Successfully mapped tissue hydration over large areas (~10 cm x 10 cm) at ~1 mm resolution.

Demonstrated ability to identify margins with minimum thickness of 2 mm.

Numerical models suggest robustness to patient-specific tissue variations.

Abstract

Accurate characterisation of margins in excised breast cancer tumours is critical to the success of surgical interventions, yet margin status is typically confirmed post-operatively using histopathology. Here we present a new approach to intraoperative margin assessment based on microwave single pixel imaging, demonstrating tissue phantom hydration mapping across large areas (~10 cm x 10 cm) at ~1 mm resolution. By leveraging the photo-induced change in microwave transparency of a silicon modulator placed under the sample, we map the microwave reflectivity and identify positive margins with deeply sub-wavelength resolution. We test the discriminatory capabilities of our approach using gelatine-based tumour phantoms with variations in water density representative of the margin and cancerous tissues of a resected tumour. We demonstrate the capability to identify, locate and quantify inadequate margins up to the typically targeted minimum thickness of 2 mm. Furthermore, using numerical modelling, we show that our approach is expected to be resilient to patient-specific tissue differences. Our technique has potential for future deployment as a real-time intraoperative tissue margin analysis tool.