Medical Health Areas of Research Concentration | LSU Physics

Research - Medical & Health

Selected Areas of Research in Our Program

Our faculty and trainees are engaged in research in a variety of topics in medical physics and health physics. In the section of our web site, we describe selected major research topics by specialty and subspecialties. In medical physics, these subspecialties include radiotherapy physics, diagnostic imaging physics, nuclear medical physics, and medical health physics. In health physics, the subspecialties include environmental health physics and medical health physics. For brevity, the topics were selectively listed. Please see our listing of research publications for addition information on recent and current research projects of our program. Publications are listed separately for peer-reviewed journal articles and graduate theses and dissertations. These may found elsewhere on our website.

Medical Physics Research Areas:

Radiation Therapy Physics

Several faculty in the program are studying fundamental physical aspects of radiation therapy, including proton therapy, intensity modulated x-ray therapy (IMXT), volumetric modulated arc therapy (VMAT), modulated electron therapy (MET).

Additional specific details are listed below.

  • Proton and Heavy Ion Radiotherapy Physics: Proton and heavy ion radiotherapy utilizes beams with a finite penetration range and sharp lateral penumbra. These allow the treatment of tumors to high doses while minimizing dose to surrounding normal tissue.  Dr. Newhauser's research group investigates a variety of topics involving proton therapy, including modeling of radiation transport of primary and stray radiations, comparative effectiveness studies of ion- and photon-beam therapies, optimization of treatment planning, prediction of patient outcomes, and microdosimetry. Dr. Newhauser and his group have also researched and published on clinical aspects of proton therapy physics, including a widely read review paper on the physics of proton therapy, an AAPM Task Group Report published in 2020 and another Task Group Report accepted for publication in 2020. In recent years, research projects have included the treatment of moving tumors with heavy ion beams, including tracking of scanned beams.

  • Electron Beam Radiotherapy: Improved treatment planning and delivery of electron beam radiotherapy is a major focus of research by Drs. Hogstrom and Carver and their research team. Electron beam dose distributions used to treat cancer-bearing treatment volumes within 6 cm of the skin surface can be made more conformal by modulating dose penetration across the electron beam, and one method of achieving this utilizes wax bolus, which is referred to as bolus electron conformal therapy (ECT). A research agreement with .decimal, Inc., funds research to improve bolus ECT, e.g. mixing it with a small fraction of IMXT to produce mixed-beam distributions superior to either modality alone. For alternative delivery methods, which utilize energy-segmented fields, the challenges of treatment planning, abutment dosimetry, and MLC delivery have been investigated. Analytical calculations using radiation transport calculations and EGSNRC Monte Carlo calculations have been used to study these problems, as well as to design dual scattering foils and collimating systems. Such research requires accurate dose measurement methods, a specialty of the research group.

  • Image-guided Radiotherapy Physics: Drs. Fontenot, Hogstrom, Solis, and Pitcher are conducting research in image-guided radiation therapy physics, gated radiotherapy, and adaptive radiotherapy. One project concentrates on usage of orthogonal x-ray imaging using the BrainLab Novalis treatment unit for radiosurgery and radiotherapy of brain and extra-cranial cancers, e.g. spine, liver, and prostate. Another project focuses on usage of megavoltage CT scanning using the TomoTherapy HiART for radiotherapy of prostate, head and neck, and other anatomical sites.

  • X-ray Capture Therapy Physics: X-ray capture therapy is a potentially new radiotherapy paradigm (chemo-irradiation) that uses monochromatic x-rays to deliver targeted radiation dose to high-Z labeled (e.g. iodine) pharmaceuticals that are preferentially taken up by cancer cells, e.g. IUdR taken up by DNA. Our research program, led by Dr. Matthews, uses the CAMD synchrotron’s monochromatic x-ray beam line to study dosimetry techniques, treatment planning dose algorithms, microdosimetry, cell biology, and small animal irradiations. A long term goal is to conduct clinical trials using a prototype laser-particle accelerator to produce monochromatic x-rays.

  • Physical Aspects of Biology and Radiation Biology:  Dr. Newhauser’s group is investigating novel computational models of blood flow in tissues, organs, and organisms. Blood flow is fundamental to normal physiology, disease, injury, and treatment. Dr. Matthews and colleagues are research a variety of topics in biology, including cell lysis. Dr. Dey’s research includes mathematical modeling of tumors using oncologic imaging information.

Diagnostic Imaging Physics

Several of our faculty are researching advanced imaging techniques, including MRI, fMRI, CT, microCT, and multi-contrast imaging.  Drs. Dey, Matthews, and Carmichael each lead research groups that are focused on diagnostic imaging projects. The areas of research include detector development, image acquisition, image reconstruction, and image analysis.

  • An example of a recently completed project is the development of a novel x-ray imaging technique called endorectal digital prostate tomosynthesis (endoDPT). endoDPT is expected to improve resolution in prostate cancer imaging for certain clinical applications.

  • Current efforts include applications of machine learning, quantitative testing of image quality and patient dose on their prototype imaging system, development of tomosynthesis image reconstruction algorithms, and development of seed localization algorithms for low dose rate brachytherapy post-implant evaluations.

Nuclear Medicine Imaging Physics

Drs. Dey, Matthews and Carmichael are pursuing research in medical nuclear imaging.

  • Current detector development projects include high-sensitivity cardiac SPECT imaging as well as hand-held and compact CZT imaging systems for intraoperative imaging.

  • Graduate students with Dr. Matthews have also worked on topics such as observer performance studies for PET/CT, quality assurance methods for PET/CT, performance characterization of megavoltage CT imaging for radiotherapy applications, and dose reduction for CT lung screening.  

  • Dr. Dey has recently also worked on tumor modeling based on oncology imaging data.

Medical Health Physics

Drs. Newhauser, Chancellor, Wang, and Matthews have pursued research pertaining to the protection of humans from medical radiation. This includes a variety of topics in radiation protection, including risk assessment, shielding, justification, and optimization. 

  • Dr. Newhauser’s group is developing of a novel theoretical framework to allow the algorithmic aggregation of risks and benefits from radiation exposures.  This has potential applications in medical, occupational, and environmental exposure settings. 

  • Dr. Chancellor’s work on radiation protection of astronauts is similar to and synergistic with medical health physics research for radiation therapy, owing to the similarities of the radiation environment in space to those in heavy ion medical accelerator facilities.

  • Drs. Chancellor, Matthews, and Newhauser have conducted variety of research projects on radiation shielding of exotic radiations, including heavy ions and synchrotron radiation.

Health Physics Research Areas:

Our faculty are engaged in a variety of health physics research topics that may be categorized as environmental health physics and medical health physics. 

Environmental Health Physics

  • Terrestrial Environmental Applications: Health physics research includes radiation detector development with safety/security applications and intercomparisons of dosimetric methods by Drs. Wang and Matthews. Dr. Wang and students also work on environmental impacts of radiation use, currently including an environmental assessment of a hypothetical low-level radioactive waste repository located in Louisiana.

  • Space Radiation and Applied Nuclear Physics: Dr. Chancellor and the Space Radiation Transport and Applied Nuclear Physics group (SpaRTAN Physics) are focused on ascertaining the impact space radiation has on both the health of human spaceflight crews and the resilience of space vehicle hardware systems. Both of these efforts require a multidisciplinary approach; and the group partners closely with radiobiologists, aerospace physicians, engineers, and applied scientist to develop novel methods for studying the interaction of the heavy-charged nuclei found in the cosmic ray spectrum with both soft and condensed matters. The SpaRTAN Physics group utilizes high-performance, multi-core computers and sophisticated numerical techniques in order to study these complex interaction dynamics that are otherwise difficult to mimic in a laboratory setting. An example would be the utilization of Monte Carlo techniques to model spallation reactions of heavy charged nuclei interacting with hydrogen-rich materials and the angular discrepancy in off-axis fragments produced by inelastic nuclear interactions in particle transport code. Our computational outcomes are experimentally validated with measurements at beam line accelerators or by applying our models to results previously published in peer-reviewed literature. These efforts have led to novel approaches to simulating the complex space radiation environment and the development of more realistic ground-based space radiation analogs.

Medical Health Physics

The Program’s research in this subspeciality of health physics is substantially similar to the subspecialty of medical physics, which also goes by the same name.  Please see the description above.