University of California, Los Angeles

Open-ended survey responses are extremely valuable since participants voluntarily share insights that they feel are necessary to express. The purpose of this study is to accurately reflect members’ perception of the AAPM climate, through analysis of open-ende...

Tumor-to-normal ratio (TNR) derived from pretreatment Tc-99m MAA SPECT/CT is widely used as a surrogate marker of perfusion in yttrium-90 (⁹⁰Y) radioembolization for patients with hepatocellular carcinoma (HCC). Delivered activity is critical for achieving ab...

Artificial intelligence holds significant promise for radiation oncology, yet clinical adoption is frequently stalled by the gap between conceptual understanding and practical implementation. This three-part educational track provides a start-to-finish playbo...

Radiopharmaceuticals, Theranostics, and Nuclear Medicine

To achieve more favorable clinical VMAT/IMRT outcomes, preclinical studies that mimic clinical practices and provide highly statistically significant small animal (SA) studies are essential. However, such high-throughput studies are currently impractical beca...

Dense lung vasculature landmarking is vital for assessing thoracic registration accuracy in treatment planning. We demonstrate an automated method for identifying vascular bifurcations in free-breathing CT images.

To quantify the precision and accuracy of a five-dimensional computed tomography (5DCT) free-breathing simulation approach in a large clinical cohort.

Aggregating large radiotherapy datasets for predictive modeling is impeded by inconsistent nomenclature. To address this, we developed a fully automated, metadata-independent framework to classify treatment plans into six Anatomic Regions and identify specifi...

Large, well-annotated databases are necessary for the development of personalized outcomes models. We evaluated the viability of using a Large Language Model (LLM) to extract patient-specific specific toxicity and progression outcomes from unstructured radiol...

Unplanned linac downtime necessitates rapid transfer of VMAT plans to backup machines. Prior methods relying on geometric leaf mapping often fail when transferring between different MLC models or beam profiles. This study validates a workflow that augments ma...

Stereotactic radiosurgery (SRS) reirradiation for locally recurrent brain metastases (BM) utilizes rigid image registration (RIR) for cumulative dose estimation to balance dose escalation against the risk of adverse radiation effects such as radionecrosis. Th...

To systematically evaluate CT number accuracy on virtual monoenergetic images (VMIs) generated by a clinical photon-counting CT (PCCT) system using projection-domain multi-material modeling with a water/iodine basis.

Radiation Dose Index Monitoring Systems (RDIMs) can report and track estimated organ and effective doses from CT scans. However, the methods to estimate these doses are not standardized. The purpose of this initial study was to assess the feasibility of perfo...

Conventional iterative closest point (ICP) algorithms capable of 3D surface registration perform best with non-deformable surfaces. Such methods are not efficient in head and neck (HN) RT, where one part of the surface is rigid (head) while another part is de...

When positioning patients for head and neck radiation therapy procedures, it can be difficult to position the patient without knowledge of the limits of motion due to physiological constraints caused by the neck vertebrae. This work seeks to develop a dynamic...

Manual segmentation of immunohistochemical (IHC) stained images is a time-consuming task that typically takes 1-2 workdays to segment all images needed for analysis. Deep learning-based methods were employed to create an AI model to automatically segment IHC...

A CT-simulation approach has been developed which images free breathing patients with lung tumors by generating a motion model that is a function of breathing amplitude and rate (5DCT). Of the >300 patients simulated with 5DCT, 13 have been simulated more tha...

To evaluate dosimetric trends and robustness of online adaptive radiation therapy for focal-boosted prostate SBRT. Materials/

MRI-guided lung SBRT has emerged as a novel treatment modality with the potential to enhance motion management and improve normal lung sparing. This retrospective study evaluates the extent of normal lung sparing achieved by real-time tracking and automatic g...

Deep learning–based dose prediction models have demonstrated high accuracy in multi-institutional challenges; however, their performance under real-world institutional domain shift remains unclear. This study evaluates the generalizability of a state-of-the-a...

Accurate delineation of Head and Neck (H&N) Gross Tumor Volumes (GTV) is a prerequisite for effective radiotherapy, represents a significant cognitive challenge, and may contribute to an observed outcomes deficit between high-volume and low-volume H&N radioth...

Online Adaptive Radiotherapy (oART) is resource and time-intensive, requiring dosimetrist, physicist, and physician involvement at each adapted fraction. The therapist-led adaptive workflow has been shown to reduce physician console-time. This study evaluates...

Lung nodule distribution is non-homogeneous, yet localized risk factors are poorly understood. This study aims to develop a computational pipeline to construct a 3D lung atlas, identifying population-level spatial trends to guide clinical diagnosis and treatm...

Photon-counting CT (PCCT) incorporates detector technology that supports quantitative imaging in routine diagnostic evaluation by reducing scanner- and patient-specific effects, thereby enabling more reliable material quantification and characterization. Prev...

To investigate whether physics-based radiomics standardization can increase agreement in radiomics extracted from radiologist-annotated regions of diffuse lung disease (DLD) phenotypes across CT reconstruction kernels and radiation doses.

Functional avoidance radiotherapy requires accurate regional lung ventilation mapping. Jacobian-based free-breathing ventilation derived from deformable image registration (DIR) of 4DCT is established but susceptible to inaccuracies caused by errors in the di...

Endobronchial Valves (EBV) are one of the few treatment options for patients with moderate to severe emphysema. Eligibility is typically assessed from CT image data analysis including Emphysema Score (RA950) and Fissure Integrity Score (FIS). However not all...

To evaluate the relationship between fat volume fraction (FVF) and Hounsfield units (HU) in unenhanced fatty lesions and to identify virtual monochromatic imaging (VMI) settings that minimize FVF quantification errors, by comparing photon-counting CT (PCCT) w...

MR-guided radiotherapy, especially adaptive therapy, involves complex, multi-stage clinical workflows that are challenging to quantify using conventional manual metrics. In-depth, quantitative, understanding of the clinical workflow can provide crucial insigh...

The incorrect patient placed on the radiotherapy couch for treatment is rare, but the consequences are potentially devastating. We developed an artificial intelligence assistance tool intended to support therapists at the treatment console to ensure the corre...

The BetaBox 2.0 is a high sensitivity, low noise instrument that measures positron and electron emissions from radiopharmaceuticals in single cell samples. The goal of these measurements is to elucidate the biological differences among individual cells by mea...

Proton therapy offers superior therapeutic ratio due to its favorable dose distribution, but accurate dose calculation remains challenging. Current methods rely on either pencil-beam algorithms (fast but inaccurate in heterogeneous media) or Monte Carlo simul...

Endobronchial Valves (EBV) are one of the few treatment options for patients with moderate to severe emphysema. Eligibility is typically assessed from CT image data analysis including Emphysema Score (Relative Area, RA950) and Fissure Integrity Score (FIS). H...

The nutritional status of head and neck cancer (HNC) patients receiving radiotherapy often declines due to treatment-related side effects. This study characterizes the effect of baseline body mass index (BMI) on overall survival and analyzes how soft tissue v...

Routine and pre-treatment clinical irradiator quality assurance (QA) is vital for ensuring safe, accurate, and reproducible patient care. A primary factor limiting statistical significance in preclinical research is the lack of reproducibility, mainly due to...

While phantom studies demonstrate high spatial accuracy for Surface-Guided Radiation Therapy (SGRT) systems, validation with live human subjects is critical. Non-rigid facial motion and the lack of a concurrent motion reference standard present unique challen...

Open-source radiotherapy quality assurance (OSQA) tools are increasingly available and offer potential value in resource-constrained settings. However, clinical adoption remains limited by gaps in validation, standardization, and implementation guidance, rath...

In investigating image-based lung ventilation, a fundamental question must be answered: is the measurement technique repeatable? Repeatability of ventilation imaging in PET and CT have been studied, but MRI is emerging. Crucial to deriving ventilation is the...

Large-scale radiotherapy research increasingly relies on heterogeneous DICOM datasets containing complex cross-references across imaging and radiotherapy objects. Beyond ingestion, downstream preprocessing for analysis and machine learning requires consistent...

To evaluate whether signed distance field regression improves geometric fidelity in intracranial vessel segmentation from non-contrast vessel wall imaging (VWI).

Standard Cone-Beam CT (CBCT) has limited utility in longitudinal lung tumor response assessment due to the presence of motion artifacts. Our proposed method of motion-compensated Simultaneous Algebraic Reconstruction Technique (mcSART) addresses these artifac...

To develop robust CMOS camera calibration methodology for non-destructive quantification of radionuclides during high-throughput radiotracer synthesis. Estimation of radioactivity is achieved through the detection of Cerenkov light emission from positrons. Th...

Gastrointestinal (GI) adverse events following 177Lu-PSMA radiopharmaceutical therapy (RPT) occur frequently, including nausea, vomiting, constipation, and diarrhea (occurring in 19-35% of patients). Despite the frequent occurrence of GI-related toxicities, t...

4DCT is widely considered the standard for lung cancer radiation therapy treatment planning (TP) despite susceptibility to breathing-related motion artifacts that often render images unusable. Five-dimensional CT (5DCT), a model-based CT reconstruction method...

To determine whether appearance-enhancing synthesis pipelines are sufficient for recovering a topologically coherent intracranial vessel tree from non-contrast MR vessel wall imaging (VWI), or whether explicit geometry-aware segmentation is required.

Administration activities of 177Lu-PSMA were chosen cautiously in the treatment of advanced prostate cancer to refrain from inducing organ toxicity. The primary aim here was to investigate the association of increased injected activities and the respective ab...

To develop artificial intelligence (AI) methods with improved repeatability and reproducibility, a recognized need is for large, publicly available, and curated imaging data sets. Notable public repositories of DICOM images exist, including the Medical Image...

Diagnostic and Interventional Radiology Physics

Bone marrow (BM) is an organ-at-risk for 177Lu-PSMA radiopharmaceutical therapy, but estimating the absorbed dose (AD) is challenged by the segmentation of disseminated BM. In this work, we evaluated the impact of two segmentation approaches on AD estimates i...

Radiopharmaceuticals, Theranostics, and Nuclear Medicine

Penile vessels’ morphology and integrity are highly relevant to diagnosis and management of erectile dysfunction, as well as treatment planning for sexual function-sparing pelvic radiotherapy. Automatic segmentation of penile vessels on CT angiograms is chall...

Radiomic feature reproducibility across CT protocols is limited by sensitivity to acquisition and reconstruction parameters. This work investigates whether standard physical image quality (IQ) metrics can quantitatively predict radiomic feature variation, ena...

On-board kV imaging systems on proton therapy machines predominantly rely on scintillator-based energy-integrating detectors (EIDs) for planar imaging and cone-beam CT (CBCT). However, EID-based CBCT is limited by suboptimal image quality and insufficient qua...

Diagnostic and Interventional Radiology Physics

Recent advances in MRI could offer patients with benign lung disease whole-lung ventilation mapping that may serve as a surrogate for pathophysiological changes such as increased airway resistance and decreased lung compliance. Ventilation maps can be derived...

Dosimetry software programs use different computational approaches which may lead to clinically relevant differences in reported absorbed doses (AD). This study aims to evaluate the impact of software methodology on AD calculations.

Diagnostic and Interventional Radiology Physics

To propose a Graph Neural Network (GNN) framework that explicitly models liver vessel topology to detect anatomical landmarks and reconstruct anatomically consistent segments.

To test the feasibility of using lung hysteresis, or the difference in inhalation and exhalation motion trajectories, as a biomarker for mechanically affected lung.

Diagnostic and Interventional Radiology Physics