Xun Jia, PhD

Advances in ‘first-principles’ models of radiation response allow, in principle, for accurate mechanism-aware prediction of how biological effectiveness and effective linear quadratic (LQ) parameters change across various experimental and clinical conditions....

Tumor growth and response to radiotherapy (RT) is a multiscale biological process encompassing cellular dynamics, extracellular transport, vascular and immune modeling. This work develops a comprehensive simulation platform to model this process with GPU acce...

To develop and validate a log file-based patient quality assurance (LFQA) system for intensity modulated proton therapy (IMPT) using a GPU-accelerated pencil beam algorithm for dose reconstruction, permitting rapid log file upload, dose reconstruction, automa...

Accurate estimation of microstructural parameters by Imaging Microstructural Parameters Using Limited Spectrally Edited Diffusion (IMPULSED) diffusion MRI, including cell size and intracellular volume fraction, is promising for monitoring radiation treatment...

CyberKnife radiosurgery provides sub-millimeter targeting accuracy but relies on highly manual planning, often requiring several days and limiting throughput and consistency for time-sensitive cases. Currently, no commercial treatment planning system offers f...

To develop and evaluate an automated approach to intelligently interpret free-text, or natural language (NL), physician treatment directives and generate patient-specific prescriptions and clinical goals within a commercial treatment planning system (TPS) usi...

Radiation therapy patient scheduling is highly complex due to stringent clinical and operational constraints, such as treatment continuity over a multi-fraction course, time for first fraction, etc. Current scheduling practice is largely manual and inefficien...

Photon-counting detector (PCD)–based cone-beam CT (CBCT) is gaining increasing interest for its potential to enable high-resolution and spectrally rich imaging. This study develops a tabletop PCD-CBCT system as a research platform and reports our progress in...

To implement a full abdominal motion model that combines respiration with gastrointestinal (GI) motility and quantify its interplay impact in pencil-beam scanning (PBS) proton therapy.

Radiotherapy (RT) for head and neck (HN) cancer frequently induces xerostomia due to radiation‑mediated parotid gland damage. Mechanistic modeling of parotid response may improve understanding of toxicity development and enable more biologically informed pred...

The study aims to develop a parameterized brachytherapy source geometry modeling framework for GPU-based Monte Carlo particle transport simulation with an integrated DICOM workflow.

Diffusion-weighted MRI (dMRI) is promising for estimating tumor microenvironment characteristics from measured signals that encode the microscopic diffusion of water molecules constrained by cellular architecture. Estimation accuracy is compromised by low sig...

Proton beam quality varies with depth in both monoenergetic and spread-out Bragg peak (SOBP) beams due to changes in track structure and local energy deposition. This study investigates hydroxyl radical-sensitive fluorescence as an intrinsic method to quantif...

Photon-counting detectors (PCD) exhibit high sensitivity for scattered photons, enabling kilovoltage (kV) scattered X-ray imaging with potential for real-time tumor tracking for lung cancer radiotherapy. The performance in this application is strongly influen...

Diffusion MRI (dMRI) is a promising imaging modality for estimating tumor microenvironment parameters, providing valuable information for early treatment response assessment in radiotherapy. High noise levels in 1.5T MRI degrade parameter estimation accuracy....

Radiation oncology accreditation programs aim to promote safety and quality in radiotherapy using nationally recognized standards. This study evaluates the impact of the ASTRO Accreditation Program for Excellence (APEx) at a single institution across three su...

Quantitative imaging of 177Lu radioactivity in radiopharmaceutical therapy is desired to capture its time-dependent biodistribution for dosimetry. We propose a novel imaging system using photon-counting detector (PCD) for high-sensitivity quantitative activit...

Accurate calibration in photon-counting detectors (PCDs) for inhomogeneous pixel responses caused by charge sharing, pulse pile-up, and energy-dependent efficiency is the most critical and challenging task for PCD-based imaging applications. Conventional gain...

Therapy Physics

To explore the application of LLM agents for simulating clinical-team collaboration in prostate cancer radiotherapy treatment planning, integrating multidisciplinary expertise to automate end-to-end radiotherapy plan generation.

To develop and validate an auto-planning approach for robust intensity modulated proton therapy (IMPT) using a frontier large language model (LLM), ChatGPT-4o, in a clinical treatment planning system (TPS) for prostate cancer, automatically managing heterogen...

Automatic treatment planning and physician’s plan preference quantification are both critical tasks in High-dose-rate brachytherapy (HDRBT) of cervical cancer for rapidly generating high-quality plans meeting physician’s intent. This study employs inverse dee...

Track-structure Monte Carlo simulations are essential for modeling stochastic energy deposition at micro- and nanoscales relevant to radiobiology and for validating experiments in solid-state microdosimeters such as silicon-on-insulator (SOI) devices. However...

To evaluate the spatial resolution of an X-ray scatter imaging system utilizing a Photon Counting Detector (PCD) for real-time lung tumor tracking. Unlike transmission imaging, scatter imaging offers direct 3D tumor localization. This study quantifies the sys...

To quantify the impact of gastrointestinal (GI) motility on pencil-beam scanning (PBS) proton therapy for abdominal cancers, and assess how fractionation and motion amplitude mitigate motility-induced interplay effects.

Supercoiled plasmid DNA is widely used to study radiation-induced DNA damage. High-resolution atomic force microscopy (AFM) measurements of radiation-induced DNA fragment-length distributions have directly provided quantitative insights into radiation effects...