Department of Electrical and Computer Engineering, Virginia Polytechnic Institute and State University, Arlington, 22203, VA, USA.|Department of Radiation Oncology, Stanford University, Palo Alto, 94304, CA, USA.|Department of Electrical and Computer Engineering, Virginia Polytechnic Institute and State University, Arlington, 22203, VA, USA.|Department of Radiation Oncology, Stanford University, Palo Alto, 94304, CA, USA.|Lombardi Comprehensive Cancer Center, Georgetown University, Washington, 20007, DC, USA. hwr@georgetown.edu.