Hunter Stephens, PhD, is a Scientist in the Pharmacometrics group at Certara. He specializes in applying mathematical and computational models to understand the pharmacokinetics and pharmacodynamics of drugs, especially radiopharmaceuticals. He has a PhD in Medical Physics from Duke University. He also holds an MS in Physics from North Carolina State University and a BS in Mathematics from Tennessee Tech University. His work in TRT has focused on building semi-mechanistic population PK models to simulate and predict absorbed and biologically effective doses to inform dose-range finding and questions of safety and efficacy. In addition, he has extensive experience in radiation dosimetry from external and internal sources.