WashU Medicine

A multi-institutional journal club (MIJC) was introduced by the AAPM’s Working Group on Multi-Institutional Journal Clubs for Residency Programs (WGJCRP) in 2021. As of 2022, 40% of therapy programs were participating. The MIJC program was intended to connect...

Modern linear accelerators maintain precise control of delivery parameters during the treatment of dynamic external beam radiotherapy treatment plans; vendors provide snapshots of these parameters using trajectory log files (TLF). This project aims to investi...

To perform comprehensive dosimetric validation of a commercially available independent Monte Carlo (MC)-based secondary dose calculation engine for clinical photon radiotherapy.

To develop and validate a novel isocentricity test using continuous axis motion and imaging during beam delivery to characterize three-dimensional isocenter walkout.

To validate an online adaptive radiotherapy (oART) workflow for a C-arm linear accelerator (LINAC) equipped with HyperSight CBCT using Imaging and Radiation Oncology Core (IROC) anthropomorphic phantoms.

This study aimed to evaluate the clinical feasibility of a dual-target 3D-motion tracking workflow for 0.35T MRI-guided stereotactic body radiotherapy (MRgRT) in upper abdominal targets. The focus was on implementing real-time, dual-plane tracking to enable h...

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....

Despite the global transition toward more precise and conformal radiotherapy, many countries currently treat with Co-60 units. This paper describes key steps, challenges and lessons learned from a successful transition from Co-60 to LINAC based radiotherapy i...

To Standardize multi-leaf collimator (MLC) leaf-end dosimetry by adjusting the physical MLC gap across multiple linacs within an enterprise.

Therapy Physics

To develop a global database of medical physics initiatives in support of a sustainable and equitable collaborative ecosystem that minimizes resource duplication and inefficiencies across stakeholders.

Traditional MRI education emphasizes physics knowledge, lectures, and artifact recognition, but often does not produce graduates who can function independently in clinical practice. We aim to define core MRI competencies for graduating medical physicists and...

Diagnostic and Interventional Radiology Physics

Radiotherapy treatment planning is a resource-intensive process characterized by multiple manual steps that can contribute to treatment delays and inter-observer variability. The Radiation Planning Assistant (RPA) is a web-based platform designed to deliver a...

Online adaptive stereotactic body radiation therapy (SBRT) reduces organ at risk (OAR) dose for abdominal targets with highly variable anatomy but significantly increases treatment time and clinical workload. Adaptive workflows are routinely assigned to left...

To design and validate reliable treatment planning and delivery verification methods for TMPRT in the phase III NRG CC-017 trial, which compares TMPRT to standard radiotherapy in adults with newly diagnosed MGMT-unmethylated glioblastomas, with these methods...

In the Phase I clinical trial (NCT05831579), we already performed the palliative spatially fractionated (GRID) proton therapy by using a collimating brass aperture. However, the existence of this brass aperture limits the flexibility of the high dose regions...

A novel, low-cost 3D surface scanning system was developed using a custom modification of the laser-profiling technique. Proof of concept was demonstrated through 3D simulation in Blender 3D software. A real-world prototype was then implemented using a consum...

In proton therapy treatment planning, several free parameters impact both plan quality and delivery time. These include spot and energy layer spacing, MU per spot or layer, and in some systems, utilization of adaptive apertures (AA). Decreasing delivery time...

Treatment planning system (TPS) beam modelling is identified as the largest cause of independent dosimetry audit failure. This study aims to develop and validate a universal beam model (UBM) specific to single-iso multi-target (SIMT) stereotactic radiosurgery...

Onboard real-time MRI imaging in MRgRT offers exceptional benefits for treating abdominothoracic cancers. However, X-ray based radiotherapy at community clinics cannot provide the same advantages. We developed a deep learning network capable of real-time 3D M...

This study investigates the feasibility of using two affordable optical surface–imaging technologies to generate detailed 3D maps of the treatment room and patient surface for detecting and mitigating potential collisions between the proton nozzle and the pat...

To validate the Exradin W2 plastic scintillator for measuring beam profiles in Leksell Gamma Knife (LGK) quality assurance and to compare its characteristics against MicroDiamond detector measurements as a filmless QA alternative.

To develop a convolutional neural network (CNN) to detect coronary artery calcium (CAC) on non-gated (free heartbeat and free breathing) simulation CT scans and evaluate the robustness of models trained on different datasets, including gated (ECG-gated with b...

Multi-plane target tracking in 0.35 T MR-guided radiotherapy (MRgRT) is beginning to emerge in clinical practice. To support safe implementation, robust and repeatable quality assurance (QA) procedures are needed. This study proposes a practical QA methodolog...

This study seeks to establish a protocol for intracavitary HDR brachytherapy treatment in a murine cervical cancer model mimicking patient treatment procedure. This procedure includes the use of large-bore simulation CT imaging and clinical treatment planning...

This work aimed to verify the dosimetric accuracy of a 0.35T MRI Linac using all five available tracking algorithms (Standard, Rigid, Small Mobile, Large Deforming, Complex Mobile) when tracking multiple targets simultaneously.

Halide perovskites, particularly CsPbBr3, present an exciting opportunity to overcome these limitations due to their high atomic number, fast charge transport, and exceptional radiation tolerance. While perovskite detectors have shown promise for low-energy x...

Treatment planning and dosimetry in 90Y-SIRT rely on accurate determination of perfused volumes (PV). Bremsstrahlung 90Y-SPECT imaging remains limited, with poor resolution and erroneous counts throughout the imaging volume. “Ground truth” identification of t...

To develop and validate a continuous two-dimensional output-factor (OF) model and to identify a measurement strategy that achieves accuracy and efficiency.

Online adaptive stereotactic body radiation therapy (SBRT) enables daily replanning to mitigate anatomic variation but increases treatment time and clinical workload. For left adrenal tumors, adaptive SBRT is frequently assigned due to the proximity of gastro...

To extend MAAS-SFRThelper with geometry-based lattice positioning tools, completing an integrated workflow from sphere generation, positioning, and VMAT optimization, to dose evaluation for SFRT planning.

To quantitatively evaluate and compare imaging performance of various kV-CBCT systems implemented on modern C-arm and O-ring linear accelerator units.

To compare HyperSight imaging systems between O-ring (Halcyon) and C-arm (TrueBeam) machine, with specific emphasis on the impact of motion in resulting dose calculation.

Onboard real-time MRI imaging in MR-guided radiotherapy (MRgRT) offers exceptional benefits for treating abdominothoracic cancers. However, gated delivery can be prolonged due to irregular patient breathing, which may diminish these advantages. We addressed t...

Stereotactic arrhythmia radiotherapy (STAR) is an emerging treatment for ventricular tachycardia (VT) that uses radiation to modulate cardiac electrophysiology (EP) and reduce VT. Registering radiation planning 3D imaging to cardiac optical maps will enable o...

The Stop-Scan-Adapt (SSA) feature introduced with the MRIdian A3i upgrade enables intra-fractional adaptation during online MR-guided adaptive radiotherapy (ART) through re-optimization without patient repositioning. While SSA efficiently responds to intra-fr...

Large-animal studies of stereotactic arrhythmia radiotherapy (STAR) are faced with financial and logistical difficulties that limit widespread implementation. We developed a single-platform STAR porcine workflow on an O-ring linac utilizing manual end-exhalat...

Gamma Knife radiosurgery (GKRS) has undergone multiple technological transitions over the past two decades. This study evaluates long-term utilization trends at a single academic institution to assess whether GKRS has remained a durable and adaptable treatmen...

Conventional methods for testing proton pencil-beams require multiple quality assurance tools that lack efficiency and spatiotemporal resolutions. Here, we used our efficient ultra-high-resolution scintillation imaging system to verify that two gantry-mounted...

To measure the neutron-ambient-dose-equivalent (H*(10)) and assess the fetal dose due to secondary neutrons in a gantry-mounted synchrocyclotron proton therapy system when an intensity modulated proton therapy (IMPT) brain treatment is delivered with the dyna...

Independent verification of IROC phantom credentialing results is valuable for institutional quality assurance and confidence in treatment planning system performance. This work aimed to verify the accuracy of a commercially available Monte Carlo (MC) dose al...

LSF derived from MAA-based nuclear medicine imaging is a standard component of 90Y-SIRT treatment-planning. Elimination of MAA-based LSF determination has been suggested in select cases to streamline 90Y-SIRT workflows and avoid the requirement of separate pl...

Therapy Physics

A novel phantom configuration is designed to measure the multi-target tracking latency of a 0.35 T MT-guided Radiotherapy System.

Clinical Trials Specialty Program

Professional

The future of medical physics depends on how effectively we train and support the next generation. As the field, certification requirements, and trainees themselves continue to evolve — driven by advances in artificial intelligence, imaging technologies, and...

Efforts to improve fluoroscopically-guided interventions (FGIs) and outcomes are partially hindered by the intrinsic variability of these procedures. Anatomic localization of fluoroscopic images can begin to address these needs, but manual image labeling is t...

Proton plans are often homogenous with minimal hotspots, which may not be ideal for ablative stereotactic body radiation therapy (SBRT). A treatment planning approach for stereotactic body proton therapy (SBPT) is proposed to match the characteristics of phot...

Artificial intelligence-based denoising has shown much promise in improving signal-to-noise in medical imaging. Our goal was to optimize Y-90 bremsstrahlung SPECT imaging following transarterial radioembolization (TARE) using a deep learning-based denoising m...

Mean absorbed dose is commonly used to interpret radiopharmaceutical therapy outcomes. For α-emitter radiopharmaceutical therapy (αRPT), however, energy deposition is stochastic at the cellular scale, while tissue-level Monte Carlo-based microdosimetry is com...

Therapy Physics

To study the cardiac and respiratory heart motion together. Cardiorespiratory motion management is a significant topic in stereotactic arrhythmia radiotherapy (STAR). Cardiorespiratory motion consists of the heart beating and respiration. Commonly studied sep...

Diagnostic reference levels (DRLs) and achievable doses (ADs) have been established in the United States for pediatric energy-integrating detector CT (EID-CT) based on ACR Dose Index Registry data. However, these benchmarks may not be directly applicable to p...

It was critical yet impossible to quantitatively assess the impact of patient-specific cardiorespiratory motion on dose plans for stereotactic arrhythmia radioablation (STAR) treatments. To fill the gap, a fast algorithm, SPM (spatial probability map), was de...

Redistribution of radioactive daughters following ²²⁵Ac decay is a major dose-limiting uncertainty in α-emitter radiopharmaceutical therapy (αRPT). Free daughter species may diffuse from their site of origin, yet their microscale fate within tissue remains po...

For single-isocenter multi-target (SIMT) stereotactic radiosurgery (SRS), benchmarking, auditing and inter-institutional standardization of dose delivery remains challenging as it requires specialized equipment and expertise. Electronic portal imaging devices...

Managing cardiac and respiratory motion is critical for stereotactic arrhythmia radiotherapy (STAR), thoracic, and breast treatments. Breath-hold cardiac 4DCT (c4DCT) is commonly required for assessing cardiac motion, while respiratory 4DCT (r4DCT) is used fo...