description: The number of sessions in a course of radiotherapy. package_name: hl7.fhir.us.mcode derivation: constraint name: RadiotherapySessions type: Extension elements: extension: {index: 0} url: pattern: {type: Uri, value: 'http://hl7.org/fhir/us/mcode/StructureDefinition/mcode-radiotherapy-sessions'} index: 1 value: choices: [valueUnsignedInt] index: 3 valueUnsignedInt: {type: unsignedInt, choiceOf: value, index: 4} package_version: 2.0.0 extensions: {} class: extension kind: complex-type url: http://hl7.org/fhir/us/mcode/StructureDefinition/mcode-radiotherapy-sessions base: http://hl7.org/fhir/StructureDefinition/Extension version: 2.0.0 required: [value, valueUnsignedInt]