This is a reasonable suggestion. FHIR's Dosage structure has been defined with the intention of being reused. See https://www.hl7.org/fhir/dosage.html and https://www.hl7.org/fhir/dosage.profile.json.html for the definitions of Dosage. If we were to adopt this approach, two steps would be required: 1) Profile Dosage to specialize it to a RadiationDosage, and 2) Add RadiationDosage as an extension to RadiationProcedure. Dosage was designed for medications, and it is not clear that it is a good choice for representing RadiationDosage: a. Dose per fraction could be represented as Dosage.doseAndRate.dose [x] b. FractionsDelivered could be represented as Dosage.timing.repeat.count c. TotalRadiationDoseDelivered is not represented in Dosage, and would have to be added as an extension. d. BodySite is given in Dosage, but it is also an element in the Procedure. We may choose to change the cardinality in Dosage to 0..0 so there is no confusion where to put the body site. e. Other elements in Dosage, such as route, maxDosePerPeriod, maxDosePerAdministration, maxDosePerLifetime, as well as many elements of Timing as not relevant. Taking a step back, there would be quite a few changes to Dosage to represent a RadiationDosage, and in the resulting profile, it could be much less clear where to put the information we want to collect. We believe this could be confusing to the user, compared to te current approach where each extension is clearly defined. We do feel that RadiationDosage could be better represented with one complex extension, than the current approach of using three separate extensions. This would allow RadiationDosage to be reusable as a 'standard' extension, as suggested by the reviewer. Therefore, we propose to replace the current multiple-extension approach with a reusable radiation dosage extension. Proposed resolution: Not Persuasive with mod