Seminars

The Promises and Pitfalls of Online Adaptive Radiotherapy

Jennifer Pursley, PhD
Senior Associate Consultant, Mayo Clinic
Online adaptive radiotherapy is a rapidly growing practice in radiation therapy, enabled by improved online imaging, integrated software to allow contouring and planning on online images, and the assistance of automation and AI to speed the process. It has promised to improve cure by increasing the dose to targets and reduce toxicity by reducing the dose to critical nearby organs that change position daily. However, there are many obstacles that make it challenging to operate and staff an online adaptive therapy program, and these challenges may limit the number of patients who are able to benefit. In this talk, I’ll review some of those challenges and considerations for developing an online adaptive therapy program.

Theranostics digital twins: A path toward personalized medicine

Emilie Roncali, PhD
Associate Professor in Biomedical Engineering, University of California Davis

Increasingly, medicine is aiming at being highly precise and personalized for each patient. Researchers and clinicians are discovering specific features of diseases that are often uniquely expressed in patients and justify personalization of treatment for optimal results. One way to achieve personalized medicine is to use medical imaging to measure physiological and biological data that help physicians design the treatment. While personalized medicine takes many forms and can combine sources of information such as genetics or physiological data, this presentation will focus on theranostics.

In the last ten years, the application of theranostics to internal radiation therapy surged with the possibility of using nuclear imaging to visualize tumors with a radioactive molecule and then use the same molecule but modified with another radioactive element to deliver a high dose of radiation specifically to these tumor sites.

The key concepts in theranostics are developing 1) a pair of radioactive compounds that bind similarly to the tumors so that the imaging precisely predicts the therapy, 2) developing computational methods that allow this type of prediction from images, and 3) developing technology that will allow high precision imaging. We will discuss these three aspects in the context of liver cancer, prostate cancer, and metastatic cancer. We will also discuss advances in nuclear imaging (single photon emission computed tomography and positron emission tomography).

Going further, high-precision images can be plugged into a numerical model of physiological and biological processes that mimics each patient’s body and allows to virtually experiment treatments to find the best option. Such models, called digital twins, are built on engineering and physics principles (e.g. transport phenomena, blood fluid modelling, chemical exchanges, and mechanics) that we will discuss through examples of research applications. In the future, we may all have a digital twin that represents our body and its evolution over time, transforming healthcare.

From Click Chemistry to Precision Neuroscience

Hartmuth Kolb, PhD
Visiting Professor, Medical Physics
University of Wisconsin–Madison

This presentation discusses a path from click chemistry to precision neuroscience, highlighting how modular, high-yield reactions (e.g., CuAAC) enable rapid PET tracer discovery and radiolabeling. Using this approach, the team advanced fluorescent tool compounds to a first-in-class tau PET tracer, [¹⁸F]T807 (flortaucipir), with low-nanomolar affinity, strong correlation to neurofibrillary tangle pathology, and minimal white-matter binding. Longitudinal tau PET analyses support individualized progression tracking and trial readouts. Blood-to-imaging workflows integrating plasma p-tau217 with confirmatory Aβ and tau PET improve screening efficiency (e.g., AHEAD 3-45 uses [¹⁸F]NAV4694 and [¹⁸F]MK6240 in early preclinical AD). Within the biomarker framework for Alzheimer’s Disease, amyloid and tau biomarkers define objective, symptom-agnostic enrollment into clinical trials as well as therapy monitoring. An industry effort currently seeks to qualify tau PET as a “reasonably likely” surrogate endpoint linked to clinical outcomes.

Beyond AD, research pipelines target additional pathologies, such as neuroinflammation (e.g. CSF1R PET for microglial imaging), synaptic density (e.g. SV2A PET), α-synuclein and TDP-43, enabled by click chemistry coupled with brain-slice autoradiography and SPR screening. Collectively, these advances enable patient-centric precision medicine across neurodegeneration, and they accelerate biomarker-driven clinical trials for therapeutic development.

Dosimetry: Emerging Radiation Detection & Imaging Techniques

Sree Bash Chandra Debnath, PhD
Assistant Professor, Loyola University Chicago- Loyola Medicine

The advancement of modern radiation therapy depends significantly on the continued development of effective detector technologies capable of optimal performance and quality assurance across diverse radiation beam treatments (photon, proton, electron, ion, etc.). The industrially developed dosimeter/detectors are still limited by the significant size requirement, volume averaging, lack of sensitivity, correction factors, energy dependency, low signal-to-noise ratio, and Cerenkov contaminations. This introduces major challenges in the current medical dosimetry due to the lack of advancement in having appropriate dosimeters for treatment planning. In this context, we are focusing on proposing a novel, extremely compact, and highly sensitive optical-fiber-based scintillating detection technique, introducing new methodologies through micro-probe dosimetry to facilitate adaptive radiation therapy, small-field beam treatment, and modern ultra-high resolution FLASH therapy (FLASH-RT). In addition, a new generation AI-integrated multi-dosimetry system will be discussed for advanced diagnostic solutions. This aims at a paradigm shift in modern radiation dosimetry to ensure quality treatment, improving the understanding of the effects of ionizing radiation on tissues, and thereby facilitating significant progress in early-stage cancer treatment.

Cell-based therapies for Parkinson’s disease

Marina Emborg, MD, PhD
Professor, University of Wisconsin-Madison

Parkinson’s disease (PD) is a progressive neurodegenerative disorder, characterized by the loss of nigral dopaminergic neurons that project into the striatum. Cell-replacement strategies are envisioned as a solution to repair the brain of patients with PD. In this presentation, I will discuss our pioneer work to develop cell-based therapies for PD and the critical role that nonhuman primate models play in the safe clinical translation of 1st-in-class therapies. Lastly, I will discuss our collaboration with Aspen Neurosciences to create an innovative neurosurgical approach for intracerebral delivery of autologous cells, which led to a successful 1/2a clinical trial for PD patients.

Prompt Gamma Imaging: Verifying Proton Therapy Treatment Dose

Steve Peterson, PhD
Associate Professor and Head of Department, University of Cape Town – Department of Physics

Proton radiation therapy provides exceptional benefits over traditional photon therapy for the treatment of cancer, resulting in lower dose to the patient and less treatment side-effects. This benefit is achieved because the protons deposit most of their energy (dose) directly into the tumor volume. Unfortunately, this concentrated energy deposition makes it difficult to produce accurate pictures of the treatment dose within a patient.

Prompt Gamma Imaging (PGI) is a promising imaging technique for producing in-vivo images of dose delivery during proton radiotherapy. PGI uses solid-state gamma-ray detectors to reconstruct images of the scattered secondary prompt gammas produced during a proton therapy treatment. The talk will discuss the work at UCT with M3D and the University of Maryland Medical Center to develop a clinical dose verification system including a nozzle-mounted PGI system.

Lastly, this talk will also discuss the UCT Proton Therapy Initiative that is working to bring clinical proton therapy to the African continent.

Resilience in Medical Physics: Thriving in a Demanding Profession

Paulina E. Galavis, PhD  Director of Physics, NYU Langone Health

Medical physics is a high-stakes, rapidly evolving profession that demands precision, adaptability, and sustained focus. Physicists face growing workloads, staffing challenges, regulatory requirements, and constant technological advances, all while ensuring top-quality patient care. Students and trainees encounter additional challenges, including steep learning curves, intense clinical expectations, and uncertainty about future career paths.

The development of resilience at both individual and group levels is crucial for achieving sustained success and enhancing overall well-being. This talk will explore practical strategies for recognizing stress, cultivating adaptability, and fostering supportive environments at personal, team, and departmental levels. The focus will be on implementing effective strategies for stress management, promoting adaptability, encouraging the development of supportive communities, and establishing environments in which physicists, students, and trainees are enabled to thrive rather than merely persevere.

Optoacoustic Breast Imaging: Current status and future trends in clinical application

Basak E. Dogan, MD
Clinical Professor, Director of Breast Imaging Research
The University of Texas Southwestern Medical Center

Optoacoustic (photoacoustic) breast imaging is an emerging hybrid modality that combines the high spatial resolution of ultrasound with the functional contrast of optical imaging. By detecting ultrasound waves generated from transient thermoelastic expansion after tissue absorption of pulsed laser light, this technique provides non-invasive, radiation-free, and contrast-free assessment of breast tissue. Clinical studies have demonstrated that optoacoustic ultrasound (OA/US) can increase specificity in differentiating benign from malignant breast lesions, significantly reducing unnecessary biopsies. Moreover, semi-quantitative OA/US features correlate with breast cancer molecular subtypes, tumor hypoxia, and angiogenic activity, offering potential for noninvasive biological profiling.

Recent research indicates that OA/US features may predict nodal metastatic burden, highlighting its prognostic value. Limitations include depth penetration, signal variability, and cost. Nevertheless, OA/US represents a promising adjunct to conventional ultrasound, with potential applications in diagnosis, subtype characterization, and treatment response monitoring, including anti-angiogenic and radiotherapy strategies.

New Chemical Tools for Next Generation Theranostics

Eszter Boros, PhD
Associate Professor of Chemistry
University of Wisconsin–Madison, Department of Chemistry

Radio-theranostics are a rapidly growing area of preclinical and clinical research; the vast majority of theranostic agents utilize radioactive metal ions. My research group specializes in developing bespoke, coordination chemistry approaches to harness validated and emerging radioisotopes. In this seminar, I will discuss 3 case studies of coordination chemistry saving the day in new and unusual ways: 1) a single molecule approach to the chelation of F-18, Ga-68 and Lu-177 2) a metal ion induced, self-degradation strategy to modulate the pharmacokinetics of Ga-68 radiopharmaceuticals, b) a new chemical tool to capture an unchelatable metal ion isotope (Ti-45).

Electron FLASH Dosimetry: Current Status and Challenges

Ahtesham Khan, PhD
Assistant Professor
University of Wisconsin–Madison

Electron FLASH radiotherapy (eFLASH-RT) has garnered significant interest due to its potential to improve the therapeutic index of radiation treatments. However, accurate dosimetry for pulsed beams at ultra-high dose rates remains one of the primary barriers to clinical translation. This presentation will review the status and key challenges in electron FLASH dosimetry, with an emphasis on both reference and verification dosimetry. The role of ultra-thin parallel plate ionization chambers in establishing reference dosimetry will be discussed, along with the application of beam current transformers for real-time beam monitoring. Complementary use of passive dosimeters for independent dose verification will also be highlighted. Finally, existing limitations and areas requiring further investigation—such as charge build-up effects and standardization of protocols—will be explored. Together, these topics provide an overview of the progress to date and the critical steps needed to enable accurate and reliable dosimetry for eFLASH-RT.

Something to Bragg About: Advancements in Proton Therapy Imaging and Planning at UW

Join us for an overview of the development and clinical integration of the new state-of-the-art proton therapy center at UW-Madison which features a gantry room as well as a fixed-beam room with upright CT. We will explore the global landscape of proton therapy, highlight innovations and examine disparities in access. We will discuss advances in imaging and treatment planning, implementation of motion management (surface guidance and real-time gating) and adaptive therapy. This will be followed by ongoing and future research initiatives at the center, with a focus on cutting-edge technologies such as FLASH therapy and the emerging potential of proton arc therapy.

Targeted NIR Fluorescent Dyes for Intraoperative Lung Cancer Visualization

Jim Delikatny, PhD
Professor of Radiology
The University of Pennsylvania

Fluorescence guided surgery (FGS) is an emerging technique employed by oncological surgeons for accurate tumor margin detection, identification of synchronous lesions and locoregional micrometastases, leading to more complete tumor excision and improved patient outcomes. Critical to this effort is the development of near infrared (NIR) fluorescent contrast agents for local or systemic administration that target specific cancer biomarkers. Employing fluorophores that emit in the NIR-I and NIR-II (SWIR) ranges provide greater tissue depth penetration, reduced light scattering and reduced autofluorescence that allow for deeper tissue imaging.

This seminar describes our efforts to design and evaluate targeted and activatable NIR I and II fluorescent imaging probes for the detection of breast and lung cancers in mouse models. We have focused on developing probes that target choline kinase (ChoKa) and cytosolic phospholipase A2 (cPLA2), critical enzymes in lipid anabolism and signaling. We will describe the translation of these probes into veterinary clinical trials for surgical margin detection in spontaneous non-small cell lung tumors in a patient canine population, and our progress towards initiating a human clinical trial.

The power of bubbles: ultrasound-responsive biomaterials for blood vessel and bone regeneration

Mario Fabiilli, PhD
Associate Professor of Radiology and Biomedical Engineering
University of Michigan – Ann Arbor

Implantable biomaterials containing bioactive molecules and/or cells can stimulate regeneration of various types of tissue. Regeneration is guided by biochemical and biophysical cues within the biomaterial. However, with conventional biomaterials, cues are preprogrammed when the biomaterial is prepared and thus cannot be dynamically changed after implantation. This limits both fundamental and translational studies, including the personalization of regenerative therapies. We are developing biomaterials that can be modulated non-invasively and in an on-demand manner using focused ultrasound. One strategy we employ is creating composite hydrogels with a phase-shift emulsion, which are liquid droplets that vaporize into bubbles upon exposure to ultrasound. By leveraging the unique interactions between ultrasound and phase-shift emulsions, we have developed strategies for controlling the release of bioactive factors as well as modulating the microarchitecture and physical properties of hydrogels. This talk will highlight our work in revascularizing ischemic tissue by promoting blood vessel formation and stimulating bone growth by enhancing osteogenic differentiation of mesenchymal stromal cells.

Ultrasound and Photoacoustic Imaging

Muyinatu “Bisi” Bell, PhD
John C. Malone Associate Professor
Johns Hopkins University

Ultrasound and photoacoustic imaging are two non-invasive techniques that allow us to peek into the body to visualize internal anatomy, offering advantageous diagnostic, surgical, and interventional guidance information. Ultrasound imaging transmits sound that is reflected and detected by an array of sensors placed in contact with the skin. Photoacoustic imaging transmits light that is absorbed, causing thermal expansion which generates sound that can be detected with the same senor array. In both cases, the sensed signals are processed using beamformers to display image information. However, conventional beamformers exclusively rely on signal amplitudes, ignore the impact of light transmission through darker skin tones, or assume uniform properties (e.g., sound speed) which overlook naturally occurring intra- and inter-patient variations.

In this talk, I will provide real-world examples of the medical imaging inequities that result from conventional beamformer design choices. I will then describe techniques to address these inequities using signal processing innovations that consider spatial correlations rather than signal amplitudes. Specific clinical applications that have the greatest potential to benefit from a coherence-based imaging approach include cardiovascular health assessments, breast cancer diagnosis and treatment, biopsies, neurosurgery, teleoperated robotic surgery, and wearable health applications with flexible arrays.

Mid-infrared imaging and sensing in biomedicine

Filiz Yesilköy, PhD
Vilas and Grainger Assistant Professor
University of Wisconsin–Madison

Label-free vibrational spectroscopy in the mid-infrared (mid-IR) spectrum (𝜆 = 2.5–25 µm) is a powerful tool for noninvasive analysis of biological samples without lengthy sample staining and preparation. This technique enables the detection of biomolecules based on their unique spectral fingerprints, where molecular vibrational energy states are inscribed as absorption peaks. Spectrochemical fingerprinting is particularly promising for biomedical diagnostics, disease monitoring, and biomarker discovery because it can simultaneously capture diverse molecular structures from biospecimens. However, when analyzing complex biological samples, conventional mid-IR absorption spectroscopy faces significant challenges. Specifically, heterogeneity in sample thickness and composition and optical scattering distort and congest spectral data, impeding reliable chemometric analyses. My work focuses on developing advanced optical analytical platforms by mastering nanotechnology, plasmonics, and metasurfaces to address the major challenges of mid-IR chemical analysis. In my talk, I will introduce numerous photonic metasurface technologies and highlight the unique light-matter interactions that are key for developing advanced biochemical sensors for medical applications.

Magnetic Resonance Fingerprinting: Opportunities and Challenges for Both Basic Science and Human Imaging

Chris Flask, PhD
Professor, Department of Radiology
Case Western Reserve University

Magnetic Resonance Fingerprinting (MRF) was first developed in 2013 to rapidly generate quantitative T1 and T2 relaxation time maps. This presentation will introduce the primary components of MRF including: highly-undersampled k-space trajectories, intentional variation in the acquisition parameters, MRF dictionary variation, and the parameter matching process. This talk will discuss how these different components can be combined and optimized in a highly rationalized in order to meet the demands for specific imaging applications. First, I will discuss how MRF methods are designed for human body imaging applications, then I will discuss the challenges and opportunities for implementing MRF on high field MRI scanners for preclinical imaging studies. In particular, I will discuss my ongoing collaborations with Dr. Marty Pagel in the development of Dynamic Contrast Enhanced – MRF methods to assess tumor perfusion in breast cancer mouse models.

Online adaptive proton therapy and the central role of time

Edmond Sterpin, PhD
Professor, KU Leuven & UCLouvain

Recent developments in online adaptive proton therapy (OAPT) have focused on overcoming anatomical variations during treatment through fast, automated workflows that integrate imaging, contour adaptation, plan re-optimization, and quality assurance. Advances include automated dose-restoration strategies for maintaining target coverage and organ-at-risk protection, as well as collaborative efforts to streamline near-real-time adaptation including full image segmentation supported by artificial intelligence. Recent investigations have highlighted that while rapid adaptation can provide substantial dosimetric and predicted toxicity benefits from an individual patient point of view, these gains decrease sharply at the level of the patient population when adaptation becomes time-intensive, emphasizing the need for highly efficient clinical workflows. Together, these findings reinforce that both plan quality and adaptation speed are critical for translating OAPT into routine clinical practice.