MR-Guided Adaptive Radiotherapy in Lung Cancer: Current Landscape and Future Directions.

Magnetic resonance-guided radiotherapy (MRgRT) delivered with MR-linac technology represents a major advance in lung cancer radiotherapy, enabling daily online adaptive planning based on high-quality soft-tissue visualization, real-time motion assessment, and anatomy-driven treatment personalization. The challenges in lung cancer treatment with conventional radiotherapy delivery due to respiratory motion, inter and intra-fraction anatomical changes make MRgRT capabilities particularly relevant. This narrative review provides an overview of the current state of the art of MR-guided adaptive radiotherapy in lung cancer, focusing on technical foundations, adaptive workflows, and clinical implementation across different disease stages. Key aspects as patient selection, adaptive decision-making, motion management strategies, and integration into routine clinical practice are discussed. Finally, emerging clinical applications and future directions-including adaptive dose personalization and integration of functional imaging-are outlined, highlighting the potential role of MR-linac-based adaptive radiotherapy as a platform for precision radiotherapy in lung cancer.