A Comparison of Spectroscopy and Imaging Techniques Utilizing Spectrally Resolved Diffusely Reflected Light for Intraoperative Margin Assessment in Breast-Conserving Surgery: A Systematic Review and Meta-Analysis

Abstract

Up to 19% of patients require re-excision surgery due to positive margins in breast-conserving surgery (BCS). Intraoperative margin assessment tools (IMAs) that incorporate tissue optical measurements could help reduce re-excision rates. This review focuses on methods that use and assess spectrally resolved diffusely reflected light for breast cancer detection in the intraoperative setting. Following PROSPERO registration (CRD42022356216), an electronic search was performed. The modalities searched for were diffuse reflectance spectroscopy (DRS), multispectral imaging (MSI), hyperspectral imaging (HSI), and spatial frequency domain imaging (SFDI). The inclusion criteria encompassed studies of human in vivo or ex vivo breast tissues, which presented data on accuracy. The exclusion criteria were contrast use, frozen samples, and other imaging adjuncts. 19 studies were selected following PRISMA guidelines. Studies were divided into point-based (spectroscopy) or whole field-of-view (imaging) techniques. A fixed-or random-effects model analysis generated pooled sensitivity/specificity for the different modalities, following heterogeneity calculations using the Q statistic. Overall, imaging-based techniques had better pooled sensitivity/specificity (0.90 (CI 0.76–1.03)/0.92 (CI 0.78–1.06)) compared with probe-based techniques (0.84 (CI 0.78–0.89)/0.85 (CI 0.79–0.91)). The use of spectrally resolved diffusely reflected light is a rapid, non-contact technique that confers accuracy in discriminating between normal and malignant breast tissue, and it constitutes a potential IMA tool.

Ultra-miniature dual-wavelength spatial frequency domain imaging for micro-endoscopy

“…This meets the ASGE guidelines and is in agreement with experimental pre-clinical SFDI studies that typically achieve values >90% for both sensitivity and specificity when comparing healthy and cancer tissue. 40,41 Next, using our method to analyze the impact of noise on resolution, we find that for absorption the FWHM of our instrument spot size is 4.1 mm versus an estimated 3.7 mm for bench-top systems presented in the literature. 17 Similarly, for scattering, we find that our spot size is 0.74 versus 0.39 mm for bench-top systems in the literature.…”

“…This meets the ASGE guidelines and is in agreement with experimental pre-clinical SFDI studies that typically achieve values for both sensitivity and specificity when comparing healthy and cancer tissue. 40 , 41 …”