海角社区

Students in the 海角社区 SpaRTAN medical physics lab are using technology to simulate biology and biological processes, such as a person鈥檚 whole-body response to radiation based on the break-down of individual cells. And the result is beautiful.

Baton Rouge鈥擮n a day-to-day basis, 海角社区 medical physics graduate student Megan Chesal might not feel like Leonardo da Vinci as she sits at her computer in her two-bedroom apartment in Baton Rouge, trying to understand the complex workings of the human body by creating highly intricate drawings. But she鈥檚 nevertheless following in his footsteps by using technology to describe biology.

Chesal develops human phantoms, which are computational 3D replicas of entire bodies. These virtual alter egos or avatars can be used for medical research to help predict outcomes without having to experiment on living beings. Chesal鈥檚 longterm goal is for her research to help in the fight against cancer, which can be treated with radiation. More immediately, however, her focus is on space radiation and its effects on the human cardiovascular system. Space radiation effects, to both soft and condensed matters, is the primary focus of the , which she helps manage.

鈥淩adiation has the power to disrupt or kill cells鈥攚hether those are healthy cells, or cancer cells.鈥�

Chesal and her fellow students are all studying radiation effects under the supervision of Jeffery Chancellor, assistant professor in the 海角社区 Department of Physics & Astronomy. The students research radiation in space, working on ways to protect astronauts and equipment from harmful background radiation, while some also look at it as a positive, in the context of medicine. In either scenario, radiation has the power to disrupt or kill cells鈥攚hether those are healthy cells, or cancer cells. The phantoms Chesal is developing can be used to study space radiation deposition and topology throughout the body鈥攕he鈥檚 a current Louisiana Space Grant graduate research fellow鈥攁s well as for other purposes, such as predicting and visualizing the distribution and accumulation of pretty much any matter or medication that enters the body.

鈥淥ur lab is unique in that we conduct research that can impact both space travel and cancer care, but helping to treat cancer was the reason I went into medical physics and it鈥檚 still something I want to do and feel passionate about,鈥� Chesal said.

The process of building a human phantom starts with a scan, such as an X-ray or magnetic resonance imaging (MRI). Through advanced computational techniques, that data is then translated into virtual 3D. Chesal鈥檚 daily challenge is to make these renderings increasingly accurate and more detailed. She spends a lot of time thinking about how to computationally describe and delineate thin and particularly radiosensitive tissues, like oral mucosa and intestinal linings. When she first started building human phantoms, she was working with voxels, or volume pixels, and has since moved on to tetrahedral models. From a computational as well as anatomical standpoint, it makes a big difference whether you鈥檙e working with squares/cubes or triangles/pyramids. The latter is much easier to scale and better at describing smooth surfaces. If you were creating a digital drawing of a heart, for example, and then had to draw a much bigger heart, you would need to add a lot more cubes. You couldn鈥檛 just make the cubes bigger鈥攊t would be like building with oversized Legos, and jagged. Pyramids, on the other hand, can stretch, without as much distortion.

鈥淚magine, a billion cells responding. You can鈥檛 run a simulation like that on a laptop.鈥�

Megan Chesal

鈥淲orking with voxels, which are like little boxes, there were regions of the body I couldn鈥檛 even describe,鈥� Chesal said. 鈥淵ou get these weird, stairstep surfaces instead of thin, smooth layers, and that can cause problems in calculating something like radiation dose, because no matter how you try, you鈥檝e either included some part of the air, or accidentally taken out parts of the body. Resolution becomes extremely important, but then the computation also becomes massive. Imagine, a billion cells responding. You can鈥檛 run a simulation like that on a laptop.鈥�

While Chesal works with tetrahedrons to add information about smaller and smaller details, making her phantoms more anatomically correct, she also collaborates closely with another graduate student in the SpaRTAN lab, Nousha Afshari, who is studying radiation effects on microscopic cells all the way up to macroscopic tissues and organs, sort of in the opposite direction鈥攆rom the super-small to the larger. (Afshari recently visited SpaceX in California along with another student in their lab, Jared Taylor, to present SpaRTAN research.) Their mutual goal is to have their research meet and then overlap, so the anatomically correct phantoms become functionally correct.

Before joining 海角社区, Afshari worked as a medical scribe at Our Lady of the Lake Voice Center in the same building as Mary Bird Perkins Cancer Center, in Baton Rouge. There, she became aware of how difficult it can be to predict outcomes for individual cancer patients鈥攅ven seemingly similar patients with the same kind of tumor.

鈥淭here are a ton of factors that influence how somebody responds to radiation as well as cancer,鈥� Afshari said. 鈥淒amage is happening at a microscopic level, and yet most of our tools make predictions based on damage at a macroscopic level. That鈥檚 why I want to help come up with better predictive models, and for my research to help bridge that gap.鈥�

With more advanced algorithms comes the promise of anyone being able to have their own computational phantom, on which medical researchers could conduct experiments, preventing what can be costly, risky, and heart-wrenching trial and error in real life.

Perhaps the most obvious implication of Chesal鈥檚 and Afshari鈥檚 work is more personalized medicine. With more advanced algorithms comes the promise of anyone being able to have their own computational phantom, on which medical researchers could conduct experiments, preventing what can be costly, risky, and heart-wrenching trial and error in real life. It is no surprise to neither Chesal nor Afshari that a lot of the knowledge we have on biological impacts of radiation today comes from experiments on animals, especially mice and rats.
 
鈥淚t鈥檚 an uncomfortable fact,鈥� Chesal said. 鈥淎 lot of biological sciences intertwine tightly with animal model studies, but we鈥檙e trying to lessen the burden on that and try to move toward proper simulations. It鈥檚 also not clear how much we even can extrapolate from a mouse to a human, or even from one human to another.鈥�

Chesal and Afshari want their phantoms to have the ability to be custom-tailored for any person, regardless of size, gender, body shape, or ethnicity.

鈥淏ut how well we鈥檒l be able to simulate and visualize stuff will still be based off of limitations in the original CT image or scan,鈥� Chesal said.

Chesal knows a lot about imaging. In pursuit of her bachelor鈥檚 degree, she worked with Joyoni Dey, associate professor in the 海角社区 Department of Physics & Astronomy. Dey holds two patents for innovations that have led to more detailed scans, while reducing dose, meaning amount of radiation, for the patient. The project that became Chesal鈥檚 honors thesis also relied on machine learning (a subfield of artificial intelligence) to improve the analysis of textures in scans to help predict tumor development.

Originally from Natchitoches, where her father manages a manufacturing plant for scroll compressors for air conditioners and her mother directs the office at the local Catholic basilica, Chesal first came to 海角社区 in 2014 for a bachelor鈥檚 degree in physics with a minor in history, and then decided to stay for a master鈥檚 in medical physics鈥攚hich now is looking more and more like it will pivot into a Ph.D.

鈥淚 have tried to leave 海角社区 and Louisiana, but I keep being reeled back in,鈥� Chesal said. 鈥淭his is the best program in medical physics I鈥檝e been able to find. So, here I am.鈥�

A recent MBA graduate of 海角社区 is Jonas Fontenot, originally from Crowley, Louisiana. As Chief Operations Officer and Chief of Physics at Mary Bird Perkins Cancer Center, Fontenot is at the forefront of the fight against cancer, especially due to advancements made through the renowned joint medical physics program and ongoing collaboration between 海角社区 and the cancer care organization.

鈥淢egan鈥檚 and Nousha鈥檚 work is key in the rapidly-growing science of precision medicine, which offers unprecedented opportunities to use increasingly detailed information to prevent, diagnose, and treat disease.鈥濃�擩onas Fontenot, Chief Operations Officer and Chief of Physics at Mary Bird Perkins Cancer Center

鈥淟ouisiana has some of the highest cancer mortality rates in the nation, so the need to advance care is critical in our state and beyond,鈥� Fontenot said. 鈥淢egan鈥檚 and Nousha鈥檚 work is key in the rapidly-growing science of precision medicine, which offers unprecedented opportunities to use increasingly detailed information to prevent, diagnose, and treat disease. It鈥檚 the future of cancer care, and they are playing a critical role in advancing this area of study within radiation oncology, which will ultimately produce better outcomes and save more lives.鈥�

The current phantoms used by the 海角社区 SpaRTAN Lab are provided by researchers at Hanyang University Radiation Engineering Laboratory, HUREL.

Read more:

Going the Distance: Innovation in Radiation Research Takes 海角社区 Medical Physics Student from Mary Bird Perkins Cancer Center to SpaceX (海角社区 Office of Research & Economic Development)

海角社区 Goes to the Moon (海角社区 Office of Research & Economic Development)