On October 17, 2025, ASTRO submitted comments on the Food and Drug Administration’s (FDA) draft guidance, “Oncology Therapeutic Radiopharmaceuticals: Dosage Optimization During Clinical Development: Guidance for Industry.”

ASTRO is generally supportive of the draft guidance, and offered suggestions related to calculating dose & performing dosimetry, encouraging trials with patient populations as earlier or definitive treatments, encouraging trial designs with model-informed or model-based methodologies as a standard consideration for dosage optimization, and supporting the preference of biologically standardized dose as compared to physical absorbed dose and the suggestion to include biologically effective dose for beta-emitters.