Wei Liu, PhD

Re-irradiation is increasingly used for patients with local recurrence or new tumors adjacent to a previously irradiated site. However, high-level evidence on re-irradiation is scarce, particularly the safety and toxicity from cumulative dose. Moreover, there...

Artificial Intelligence (AI) has undergone transformative advancements, revolutionizing medical imaging and radiation therapy with unprecedented precision and efficiency. Breakthroughs in agentic AI, foundation models, and interpretable AI have significantly...

In proton therapy, misalignment between planning and repeat CT arises from variations in patient positioning, physiological motion, and treatment-related anatomical changes, compromising contour propagation and treatment plan adaptation. Conventional deformab...

Dose-averaged linear energy transfer (LETd) is increasingly used to characterize biological risk in proton therapy. However, LET definitions differ among treatment planning systems. RayStation 2023B reports LET-to-water, whereas Monte Carlo engines such as MC...

Pencil beam scanning (PBS) proton therapy provides highly conformal dose distributions that are increasingly leveraged for postmastectomy radiation therapy (PMRT) to reduce cardiopulmonary exposure. However, implant-based reconstruction in the setting of PMRT...

Accurate patient setup in deep inspiration breath hold (DIBH) proton therapy is critical due to steep dose gradients, limited range robustness, and the frequent use of tight clinical target volume (CTV) margins. This study introduces a CT-on-Rails (CTOR)–base...

Monte Carlo (MC) dose calculation is the gold standard for CyberKnife radiotherapy, but its clinical integration is hindered by prohibitive computational latency. We proposed a physics- and spatially-informed diffusion model with Vision Transformer (PSIDMV) t...

Therapy Physics

Medical physicists are leading the clinical integration of adaptive radiotherapy (ART), using advanced imaging, automation, and dose recalculation tools to personalize treatments in near real-time. While current implementations primarily adapt to anatomical c...

Static apertures in pencil beam scanning (PBS) proton therapy improve lateral dose falloff but are optimal only for a single energy layer and perform poorly for shallow targets where range shifters increase spot size. This work proposes dynamic individual spo...

Clinical Trials Specialty Program

The rapid emergence of foundation AI models, large-scale pre-trained architectures such as vision transformers, diffusion models, and multimodal encoders, has ushered in a transformative era in medical image analysis. Leveraging massive natural and/or medical...

Therapy Physics