George Xu, professor of nuclear and biomedical engineering, leads an interdisciplinary, NIH-funded team that is developing 3-D virtual patient models for the computation of radiation doses in imaging and in treatment of cancer patients. The result is enabling safer, more accurate, and more effective radiation therapy and nuclear medicine imaging.
In earlier work, Xu put together his first virtual patient, VIP-man (Visible Photographic man), a computer model that combines anatomical information about internal organs with computer codes that more accurately simulate the effects of radiation exposure on internal organs and tissues.
VIP-man is of daunting proportions, containing three billion voxels of information (a voxel is a 3-D image element). VIP-man accounts for the density, atomic composition, and anatomical shape of dozens of organs, since these factors can affect the travel of radioactive particles through the body. It provides insight on how sensitive tissues such as skin, gastrointestinal track mucosa, eye lenses, and red bone marrow respond to radiation.
Xu’s interdisciplinary team now includes researchers from Rensselaer, Vanderbilt University Medical Center, the University of Florida, and Massachusetts General Hospital. The team is creating a library of 3-D models to represent a range of male and female subjects of different ages, shapes, sizes, or ethnicity. They recently completed the extremely challenging task of modeling a pregnant female at three, six, and nine months to help doctors safeguard the developing fetus when treating an expectant mother who needs scanning or cancer therapy.
In a new collaboration with Suvranu De, associate professor of mechanical engineering who specializes in biomechanics, Xu has begun work on advanced 4-D patient models that include organ motions, taking time into account. Xu and De have received funding from NIH for their quest to give the virtual model the ability to simulate breathing in real time. They are collaborating with clinical colleagues at the Cancer Therapy & Research Center in San Antonio, Texas.
See also: A Virtual Patient To Simulate Real-Time Organ Motions (Rensselaer Research Review)