Pathway to Demonstrating Clinical Efficacy of Microwave Breast Imaging: Qualitative and Quantitative Performance Assessment

Abstract

In the last five years alone, there has been an increasing number of operational microwave breast imaging systems used in clinical trials, with increasingly large and diverse patient populations. However, despite this increased activity and volume of clinical evidence motivating research in the modality, large differences exist in how studies evaluate and report their findings. In this work, the qualitative and quantitative metrics used to measure both image quality and clinical effectiveness and efficacy are reviewed in detail. Image quality, effectiveness and efficacy do not have precise or agreed definitions and the differences between these definitions are discussed in detail. Finally, based on these understandings, the current evidence for clinical acceptance of microwave breast imaging is reviewed, with an emphasis on gaps in the trial populations to date.

Review and Analysis of Tumour Detection and Image Quality Analysis in Experimental Breast Microwave Sensing

“…The analysis of the quality of reconstructed images is an important aspect of research into any diagnostic imaging modality. The quality of reconstructed images can be evaluated quantitatively, using image quality metrics, or qualitatively [18]. Qualitative approaches typically consist of subjective, textual descriptions of the images (without referring to any quantitative image features) and are not well-suited for inter-image comparisons or image quality analysis due to their subjective nature [18].…”

“…The quality of reconstructed images can be evaluated quantitatively, using image quality metrics, or qualitatively [18]. Qualitative approaches typically consist of subjective, textual descriptions of the images (without referring to any quantitative image features) and are not well-suited for inter-image comparisons or image quality analysis due to their subjective nature [18]. Quantitative descriptions are advantageous because they allow for inter-image comparisons, facilitating the assessment of different image reconstruction and signal processing algorithms.…”

“…In addition to quantitative and qualitative analysis at the individual image level, the overall performance of breast tumour detection can be evaluated with respect to diagnostic sensitivity and specificity. The sensitivity and specificity of a modality are two of the primary metrics of clinical relevance and must be considered in tandem when evaluating the efficacy of a diagnostic technique [18]. A sensitive method with poor specificity may not be useful as a diagnostic tool, particularly for breast cancer screening, where many more true negatives (healthy scans) exist in the screening population than true positives (scans of tumour-containing breasts).…”

“…A sensitive method with poor specificity may not be useful as a diagnostic tool, particularly for breast cancer screening, where many more true negatives (healthy scans) exist in the screening population than true positives (scans of tumour-containing breasts). The rigorous estimation of the potential diagnostic performance of BMS is another existing challenge within the research field [18].…”

Microwave imaging for monitoring breast cancer treatment: A pilot study

“…Reports of scanning breast cancer patients with microwave technologies were recently summarized in Ref. 11. With radar systems, testing focuses on tumor detection as radar images are designed to detect property differences.…”