Steffie Peters is a medical physics expert at Radboudumc Nijmegen, specialized in Radiology and Nuclear Medicine, with over 10 years of experience in molecular imaging and radionuclide therapy. Her work focuses on the clinical implementation of emerging molecular radiotherapies and the optimization of personalized dosimetry to support precision treatment strategies. She chairs the national Dosimetry Core Unit initiative, which aims to translate quantitative imaging and dosimetry approaches into clinical practice and improve understanding of absorbed dose–effect relationships to enable optimal therapy planning. She obtained her PhD on dosimetry in personalized PSMA therapy, bridging technological innovation with clinical applications. Throughout her career, she has collaborated with clinicians, researchers, and industry partners to advance theranostics and precision medicine. She actively contributes to the national and international medical physics community through NVNG, NVKF, EFOMP, and EANM committees, scientific initiatives such as DECISIVE, and education in dosimetry and radiobiology, including the annual Radboud Summer School.