Bladder-sparing therapy for muscle-infiltrating bladder cancer

Multiparametric MRI in Era of Artificial Intelligence for Bladder Cancer Therapies

This review focuses on the principles, applications, and performance of mpMRI for bladder imaging. Quantitative imaging biomarkers (QIBs) derived from mpMRI are increasingly used in oncological applications, including tumor staging, prognosis, and assessment of treatment response. To standardize mpMRI acquisition and interpretation, an expert panel developed the Vesical Imaging-Reporting and Data System (VI-RADS). Many studies confirm the standardization and high degree of inter-reader agreement to discriminate muscle invasiveness in bladder cancer, supporting VI-RADS implementation in routine clinical practice. The standard MRI sequences for VI-RADS scoring are anatomical imaging, including T2w images, and physiological imaging with diffusion-weighted MRI (DW-MRI) and dynamic contrast-enhanced MRI (DCE-MRI). Physiological QIBs derived from analysis of DW- and DCE-MRI data and radiomic image features extracted from mpMRI images play an important role in bladder cancer. The current development of AI tools for analyzing mpMRI data and their potential impact on bladder imaging are surveyed. AI architectures are often implemented based on convolutional neural networks (CNNs), focusing on narrow/specific tasks. The application of AI can substantially impact bladder imaging clinical workflows; for example, manual tumor segmentation, which demands high time commitment and has inter-reader variability, can be replaced by an autosegmentation tool. The use of mpMRI and AI is projected to drive the field toward the personalized management of bladder cancer patients.

High-grade hyperinvasive sarcomatoid urothelial bladder carcinoma demonstrating complete response to bladder-preserving chemoradiation

The standard treatment for locally advanced urothelial bladder carcinoma is radical cystectomy or chemoradiation. Sarcomatoid urothelial carcinoma, a rare tumour, is treated with radical cystectomy because the response to radiation therapy alone is poor in other sarcomas. We report a case of high-grade hyperinvasive urothelial bladder carcinoma with sarcomatoid differentiation. The patient refused cystectomy, and so a chemoradiation regimen was devised for her treatment. She completed the regimen and has since demonstrated a complete response to chemoradiation therapy clinically and pathologically by biopsy. The patient has therefore been able to attain a complete response while preserving a functional bladder.