The phrase "peak external dose" refers to the highest level of exposure to radiation that a person receives from sources outside of their body, such as medical equipment or environmental factors. Synonyms for this term can include maximum external dose, highest external exposure, or peak radiation dosage. All of these phrases refer to the same concept of the greatest level of radiation exposure a person can encounter from sources outside of their body. It is important to accurately measure and understand this dose in order to assess potential health risks and develop safe radiation exposure guidelines.