BBB.3.1.1 Message Sequencing

Figure BBB.3.1.1-1 illustrates a message sequence example in the case where a treatment procedure delivery is requested and performed by a delivery device that has internal verification capability. In the example, no ‘setup verification’ is performed, i.e. the patient is assumed to be in the treatment position. Unified Procedure Step (UPS) is used to request delivery of a session of radiation therapy (commonly known as a “fraction”) from a specialized Application Entity (a “Treatment Delivery System”). That entity performs the requested delivery, completing normally. Further examples could be constructed for discontinued, emergency (unscheduled) and interrupted treatment delivery use cases, but are not considered in this informative section (see DICOM Part 17 for generic examples).

In this example the Treatment Delivery System conforms to the UPS Pull SOP Class as an SCU, and the Treatment Management System conforms to the UPS Pull SOP Class as an SCP. In alternative implementations requiring on-the-fly scheduling and notification, other UPS SOP classes could be implemented.

Italic text in Figure BBB.3.1.1-1 denotes messages that will typically be conveyed by means other than DICOM services.