Deep Learning vs. Radiomics for Predicting Axillary Lymph Node Metastasis of Breast Cancer Using Ultrasound Images: Don't Forget the Peritumoral Region.

Qiuchang Sun,Desheng Sun,Dong Liang,Zhi-Cheng Li,Yuanshen Zhao,Ling Li,Kai Yan,Xiaona Lin

doi:10.3389/fonc.2020.00053

Abstract

Objective: Axillary lymph node (ALN) metastasis status is important in guiding treatment in breast cancer. The aims were to assess how deep convolutional neural network (CNN) performed compared with radiomics analysis in predicting ALN metastasis using breast ultrasound, and to investigate the value of both intratumoral and peritumoral regions in ALN metastasis prediction.Methods: We retrospectively enrolled 479 breast cancer patients with 2,395 breast ultrasound images. Based on the intratumoral, peritumoral, and combined intra- and peritumoral regions, three CNNs were built using DenseNet, and three radiomics models were built using random forest, respectively. By combining the molecular subtype, another three CNNs and three radiomics models were built. All models were built on training cohort (343 patients 1,715 images) and evaluated on testing cohort (136 patients 680 images) with ROC analysis. Another prospective cohort of 16 patients was enrolled to further test the models.Results: AUCs of image-only CNNs in both training/testing cohorts were 0.957/0.912 for combined region, 0.944/0.775 for peritumoral region, and 0.937/0.748 for intratumoral region, which were numerically higher than their corresponding radiomics models with AUCs of 0.940/0.886, 0.920/0.724, and 0.913/0.693. The overall performance of image-molecular CNNs in terms of AUCs on training/testing cohorts slightly increased to 0.962/0.933, 0.951/0.813, and 0.931/0.794, respectively. AUCs of both CNNs and radiomics models built on combined region were significantly better than those on either intratumoral or peritumoral region on the testing cohort (p < 0.05). In the prospective study, the CNN model built on combined region achieved the highest AUC of 0.95 among all image-only models.Conclusions: CNNs showed numerically better overall performance compared with radiomics models in predicting ALN metastasis in breast cancer. For both CNNs and radiomics models, combining intratumoral, and peritumoral regions achieved significantly better performance.

Highlights

Breast cancer is the leading malignancy in females [1]
The nodal status was assessed by surgical methods such as sentinel lymph node biopsy (SLNB) and axillary lymph node dissection (ALND) [3]
The convolutional neural networks (CNN) built on each region performed better than the corresponding radiomics model built on the same region in terms of AUC and accuracy, but the differences of AUCs between the CNNs and their corresponding radiomics models were not statistically significant (Image-only CNN vs. Radiomics: Intratumoral: AUC 0.748 vs. 0.693, p = 0.534; Peritumoral: AUC 0.775 vs. 0.724, p = 0.531; Combined-region: AUC 0.912 vs. 0.886, p = 0.601)

Summary

Introduction

Breast cancer is the leading malignancy in females [1]. Axillary lymph node (ALN) metastasis status is one of the most important factors in guiding treatment decision making in breast cancer [2]. According to the guideline from American Society of Clinical Oncology, SLNB is considered to have a high overall accuracy ranging from 93 to 97.6% with a relatively low false negative rate (FNR) ranging from 4.6 to 16.7% in detecting axillary metastasis [4]. These surgical approaches have been considered controversial due to the invasiveness, potential complications, and possible overtreatment [3,4,5,6]. No studies have assessed breast ultrasound-based CNN in predicting ALN status for breast tumor

Methods

Results

Conclusion