Johns Hopkins University School of Medicine

Therapy Physics

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...

Modern radiation therapy increasingly requires deforming prior dose to new CT scans for re-irradiation. Current validation methods report whole-organ agreement but lack spatial specificity and corrective guidance. This study developed a subregion evaluation t...

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.

Quantitative image-based dosimetry for radiopharmaceutical therapy (RPT) increasingly relies on large, multi-organ mechanistic models of physiologically based pharmacokinetics (PBPK). While PBPK models often fit clinical data well, the extent to which their i...

We present a small-animal SPECT-CT system based on CZT imaging spectrometers and a rapidly switchable dual-FOV apertures. The system supports both total-body imaging and focused, high-resolution imaging. These capabilities address a key need in preclinical ra...

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 absence of defined dose tolerances and the uncertainty in radiation sensitivity among airway subsegments highlight the need to evaluate imaging-based airway changes in patients receiving radiotherapy for central and ultracentral thoracic tumours. This stu...

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...

To develop and validate a deep learning framework for high-accuracy pseudo-CT synthesis from rapid, multi-parametric Magnetic Resonance Fingerprinting (MRF) for liver radiotherapy. This work addresses the technical challenge of translating quantitative tissue...

Accurate estimation of lifetime dose accumulation in patients undergoing re-irradiation therapy is essential for assessing long-term toxicity risks and evaluating the effectiveness of multiple radiotherapy (RT) courses. Currently, no standardized practice exi...

Respiratory-induced interplay effects in spot-scanning proton therapy can lead to dose degradation for lung cancer patients treated under free-breathing conditions. While motion mitigation techniques such as deep-inspiration breath-hold or abdominal compressi...

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....

FLASH radiotherapy delivers curative dose to tumor at ultra-high dose rates (UHDR,>40Gy/s) while mitigating normal tissue toxicity. However, data on late-responding tissues are limited, halting its safe clinical translation. Owing to its steep dose–response a...

αRPT is a promising treatment modality that is largely impervious to the mechanisms of resistance associated with chemotherapy, conventional radiotherapy, targeted (pathway-inhibition) therapies, and immunotherapy. Osteosarcoma (OS), which frequently expresse...

Therapy Physics

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.