Abstract
The U.S. Food and Drug Administration (FDA) has proposed a regulatory shift in the early-phase development of positron emission tomography (PET) radiopharmaceuticals, specifically regarding the requirement for animal-based dosimetry in first-in-human (FIH) studies. This editorial discusses the implications of the FDA's recent Advisory Committee briefing, which supports the omission of preclinical dosimetry under defined conditions for radiopharmaceuticals labeled with (18)F, (11)C, (68)Ga, (64)Cu, (82)Rb, and (13)N. The proposed policy reflects a shift toward a more streamlined, evidence-based approach to FIH studies while maintaining stringent standards for patient safety.