A researcher from the Louisiana State University (LSU) Biological and Agricultural Engineering department has 3D printed a life-sized phantom body for radiation therapy research and testing. Measuring 5’1”, the 3D printed model is the first of its kind.
About a year ago, LSU researcher Meagan Moore set out to create a phantom model that was not only shaped like a real person’s body but that was also the same scale. Recently, Moore succeeded in producing the phantom model, which she named Marie.
The 3D printed body, which measures in at five feet one inch in height, can be used to test radiation exposure to help determine the best angle for therapies or dose distribution. Marie, which weighs 15 lbs and can hold up to 36 gallons of water for eight hours, is reportedly the first of its kind in that it is the same size as an actual (albeit, short) person.
“Phantoms have been used in medical and health physics for decades as surrogates for human tissue,” Moore explained. “The issue is that most dosimetric models are currently made from a standard when people of all body types get cancer. No personalized full-body phantoms currently exist.”
In creating Marie, Moore used 3D scans of five women’s bodies, captured at the Pennington Biomedical Research Center. With these scans, she modeled a realistic female phantom that could be 3D printed from a bioplastic material and filled with water to mimic the density of a patient’s body.
The phantom body was 3D printed over the course of 136 hours using a BigReg 3D printer. Because of the model’s scale, Moore had to separate the print into four separate parts, which were assembled using a combination of soldering, friction stir welding and sandblasting. A pipe used for dose measurements was integrated into the body’s midline, running from the detachable head to the pelvic floor.
Though the 3D printed model took a year to develop, it was ultimately produced for just $500—much less than what generic phantom models, with no limbs, can cost (they run around $40,000).
In her project, Moore was determined to recreate a female body for the phantom model. “I specifically wanted to work with a woman because, in science, women typically aren’t studied because they’re considered complex due to a variety of reasons,” the researcher explained. “I want a person with the most complex geometry.”
Beyond 3D printing the body, Moore also had to do extensive water testing to ensure that when filled with water, Marie would not burst or leak—something that could damage expensive radiation equipment. In these tests, Marie was filled with 36 gallons of water to see if it could hold it for 4.5 hours. In the end, Moore had to add some PVC pipes to catch minor leaks and coated the body with a roofing sealant.
Last October, Moore sent Marie to the UW Medical Cyclotron Facility in Seattle for fast neutron therapy testing. Fast neutron therapy is a specialized treatment that uses external beam radiation to treat tumours that are radio resistant.
“What I’d like to see for this project is the research to be used as foundational work to personalize cancer treatments for people with more complex treatments,” Moore added. “Children and breast cancer patients have really differing morphology that is usually very difficult to treat. I find that the more we learn about any body, the more complex it’s going to be. We’re still getting medicine wrong on a lot of levels. We have a lot to learn.”