Federated learning in cancer imaging: a comprehensive review and future outlook

The rapid development of artificial intelligence has promoted the advancement of data-driven AI medical models, bringing transformative changes to the field of traditional cancer imaging by significantly improving diagnostic accuracy. However, despite these remarkable achievements, a fundamental challenge remains: data privacy. The sensitive nature of medical data and stringent privacy regulations often limit data sharing and collaboration between institutions, hindering the development of robust and generalizable AI models. Federated learning has emerged as a promising solution to address this challenge. By enabling multiple institutions to collaboratively train artificial intelligence models without sharing their local datasets, federated learning reduces the privacy leakage risks associated with conventional centralized AI training while utilizing the collective power of diverse medical data. From 2019 to 2026, extensive research has explored the applications of federated learning in cancer imaging, demonstrating its potential to advance the field while preserving patient confidentiality. In this review, we provide a comprehensive overview of the progress in applying federated learning to cancer imaging, highlighting key studies and their contributions. We also discuss the unique challenges facing federated learning, such as data security, data heterogeneity, and communication overhead. Finally, we explore some potential future research directions. This review aims to provide insights into the evolving role of federated learning in cancer imaging.