Lei Xing, PhD

To develop and validate a unified multimodal medical foundation model that combines visual understanding, cross-modal generation (image-text translation), and interpretable reasoning with visual grounding, and to quantify the gains enabled by multi-objective...

Sparse detector arrays commonly used for patient-specific radiotherapy quality assurance (QA) cannot provide complete spatial dose distribution measurements, leading to uncertainties particularly in high-gradient dose regions.The goal of this project is to de...

Recent advances in nanophotonic engineering have enabled subwavelength nanostructures to be patterned onto conventional scintillating materials, significantly enhancing light yield by both amplifying and directing emission toward the detector. This study repr...

Deep learning-based image reconstruction has shown substantial promise for addressing the highly non-uniform and under-sampled projections encountered in nonstop gated CBCT (ngCBCT). However, due to the statistical nature of data-driven learning and inherent...

The significant tissue-sparing advantages of upright proton therapy (UPT) make it an appealing treatment for pediatric patients, yet its widespread use is limited by the lack of a commercially available solution for upright anesthesia-assisted treatment. Addi...

Precise proton therapy treatment planning relies on the synergy between the superior soft-tissue definition obtained from MRI and the accurate relative stopping power (RSP) maps derived from CT. However, standard workflows that utilize separate scans are ofte...

Fast and accurate dose calculation is a key requirement for real-time adaptive radiotherapy, particularly for emerging image-guided radiation therapy systems. Monte Carlo methods and existing treatment planning system (TPS) algorithms do not achieve the compu...

Although most patients with Hodgkin lymphoma (HL) are cured with chemotherapy with or without immunotherapy, a subset fails to respond to first-line therapy. Baseline clinical factors alone do not reliably identify nonresponders. Baseline PET radiomic feature...

The clinical utility of low field MRI is limited by inherently low signal-to-noise ratio (SNR). Effective feature modeling plays a vital role in image denoising yet modeling long-range feature dependencies are computationally expensive. This study investigate...

In non-coplanar SBRT/SRS, efficient high-resolution volumetric imaging under limited-angle non-coplanar CBCT (LA-NC-CBCT) acquisition is critical for avoiding potential collisions while ensuring treatment delivery accuracy. However, severe data occlusion outs...

Upright radiotherapy offers physiological and dosimetric advantages. Mevion S250-FIT, world’s first clinical ultra-compact synchrocyclotron-based upright proton therapy system, incorporates a novel upright CT for treatment planning and image guidance. This st...

To develop and validate a fully automated, cost-effective Field-in-Field (FiF) planning script within the Varian Eclipse Scripting API (ESAPI) environment. The project aims to improve the plan quality and efficiency for breast radiotherapy by leveraging Eclip...

Upright radiotherapy offers favorable physiological and geometric conditions compared with conventional supine delivery. However, posture-induced anatomical deformation complicates the alignment of supine diagnostic images with upright simulation and treatmen...

While MR-guided radiotherapy enables real-time, soft-tissue–based motion management, clinical 2D cine MRI often sacrifices spatial resolution to maintain frame rate, which can contrast oncological contrast. This study aims to optimize a 2D cine MRI protocol o...

Commissioning and performance validation of the world’s first ultra-compact upright proton therapy system and establish benchmarks for this novel treatment delivery paradigm.

The global prevalence of Parkinson’s disease (PD) is rising in tandem with a rapidly aging population. Transcranial sonography (TCS) has emerged as a promising tool for early diagnosis, as it is radiation-free, highly accessible, and cost-effective. Specifica...

Therapy Physics

In respiratory gating radiotherapy (RG-RT), pretreatment imaging—particularly gated cone-beam CT (gCBCT)—is essential but operationally inefficient. Current gCBCT on C-arm linear accelerator is time-consuming (2–8 minutes) and often requires re-scans when gat...

Accurately decoding the spatiotemporal complexities of the human brain requires capturing the intrinsic physical geometry of functional imaging data. Traditional dimensionality reduction methods often struggle with the non-linear, time-varying nature of the B...

Nonstop gated CBCT (ngCBCT) was developed to overcome the limitations of current gated CBCT (gCBCT), enabling 2-8x faster acquisitions and 2.5-3.5x lower imaging dose. However, ngCBCT produces highly non-uniform and under-sampled projection data that challeng...

Current motion management systems are reactive: they detect patient displacement but require 200-400 ms to respond. This limitation prevents anticipatory intervention during breath-holds, forcing patients to their physiological limits before the system can re...

Conventional radiomics modeling assumes handcrafted features to be independent variables, overlooking structured inter-feature relationships that encode tumor heterogeneity and limit robust generalization across institutions. We propose a novel interaction-aw...