The Diagnostic Performance of Machine Learning in Breast Microwave Sensing on an Experimental Dataset

Objective: This paper assesses the diagnostic performance of deep learning methods for tumour detection in breast microwave sensing (BMS). Methods: A convolutional neural network (CNN) was used to predict the presence of a cancerous lesion in data from experimental scans of MRI-derived phantoms. An experimental dataset containing data from 1257 scans was used. The CNN was compared to a similarly sized dense neural network (DNN) and logistic regression classifier. Results: The CNN was able to exploit the sinogram data structure to achieve diagnostic performance significantly better than random classification, while neither the DNN nor logistic regression classifiers could generalize to unseen test data. The area under the curve of the receiver operating characteristic curve of the CNN classifier was estimated to be between (78 $\pm$ 3)% and (90 $\pm$ 3)%, where the upper estimate was obtained when the testing set was constrained to consist of phantoms with breast volumes that are within the volume bounds of the training set and when the tumour was located at the same vertical position as the system antennas. Conclusion: The results obtained in this investigation demonstrate the potential of combining deep learning and BMS systems for breast cancer detection. Impact: This paper provides an estimate of the diagnostic performance of an air-based BMS system using deep learning methods for automatic tumour detection on a sizable experimental dataset. The performance was found to be comparable to that of AI-assisted mammography and marks a first step toward larger-scale investigations in BMS.