Radiomics and deep learning fusion model based on multiphasic CT for predicting HER2 expression status in bladder

Wenbang Pan1, Liu Yang1, Lin Yang1

  • 1Department of General Surgery, Dalian Second People's Hospital, Dalian, China.

Abstract

Insights

A new tri-phasic CT imaging model accurately predicts Human Epidermal growth factor Receptor 2 (HER2) expression in bladder cancer. This noninvasive approach aids in selecting patients for targeted antibody-drug conjugate (ADC) therapy.

Area of Science:

  • Oncology
  • Radiology
  • Medical Imaging

Background:

  • Human Epidermal growth factor Receptor 2 (HER2) overexpression is a critical therapeutic target in bladder urothelial carcinoma (BLCA), particularly for antibody-drug conjugates (ADCs).
  • Current immunohistochemistry (IHC)-based HER2 assessment in BLCA faces limitations due to intratumoral heterogeneity and sampling bias.
  • There is a significant need for noninvasive, reliable imaging-based methods to predict HER2 expression status in BLCA.

Purpose of the Study:

  • To develop and validate a noninvasive, imaging-based multimodal model for predicting HER2 expression status in BLCA.
  • To utilize tri-phasic computed tomography (CT) imaging features for HER2 status prediction.
  • To assess the performance of the multimodal model against single-modality approaches.

Main Methods:

  • A cohort of 411 patients with BLCA from three institutions underwent tri-phasic contrast-enhanced CT and HER2 IHC.
  • Patients were categorized as HER2-positive (IHC 2+/3+) or HER2-negative (IHC 0/1+).
  • Radiomics, 2.5D/3D ResNet50 deep learning, clinical, and multimodal fusion models were developed and evaluated using ROC analysis, calibration curves, and decision curve analysis.

Main Results:

  • Tumor architecture, hydronephrosis, pelvic pain, and lymph node status were identified as independent predictors of HER2 positivity.
  • The 2.5D ResNet50 deep learning model achieved an external AUC of 0.827, outperforming the 3D model (AUC=0.608).
  • The multimodal fusion model demonstrated superior performance with external AUCs of 0.873, accuracy 0.819, sensitivity 0.857, and specificity 0.784, significantly outperforming single-modality models.

Conclusions:

  • A tri-phasic CT-based multimodal model provides a noninvasive method for assessing HER2 expression status in BLCA.
  • This imaging-based model shows promise for identifying patients who may benefit from HER2-targeted ADC therapy.
  • The multimodal approach offers a more accurate and reliable prediction of HER2 status compared to individual imaging or clinical factors.