Digital Pathology Ordering & Workflow (DPOW)
0.1.0-current - ci-build
Digital Pathology Ordering & Workflow (DPOW), published by IHE Pathology and Laboratory Medicine Technical Committee. This guide is not an authorized publication; it is the continuous build for version 0.1.0-current built by the FHIR (HL7® FHIR® Standard) CI Build. This version is based on the current content of https://github.com/IHE/PaLM.DPOW/ and changes regularly. See the Directory of published versions
The Digital Pathology Ordering & Workflow (DPOW) Profile provides specifications for integrating the Physical Asset Workflow Manager (PAWM), the Digital Asset Workflow Manager (DAWM), and the Image Manager / Image Archive (IMA) in support of the end-to-end digital pathology ordering and workflow process.
DPOW addresses the data flows required to:
DPOW represents an intermediate layer in the full clinical digital pathology workflow. The upstream image acquisition workflow is covered by the IHE PaLM DPIA profile. Diagnostic reporting and result distribution are covered by other profiles (e.g., APSR). Together, these profiles constitute the full integration requirements for a clinical digital pathology deployment.
This section defines the actors, transactions, and content modules in this profile. General definitions of actors are given in the Technical Frameworks General Introduction Appendix A. IHE Transactions can be found in the Technical Frameworks General Introduction Appendix B.
The figure below shows the actors directly involved in the DPOW Profile and the relevant transactions between them.
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graph LR
PAWM["Physical Asset Workflow Manager\n(PAWM)"]
IMA["Image Manager /\nImage Archive\n(IMA)"]
DAWM["Digital Asset Workflow Manager\n(DAWM)"]
PAWM -->|"[LAB-100] Physical Asset Registration\nOML^O21"| DAWM
PAWM -->|"[LAB-101] Case Update\nOML^O21"| DAWM
DAWM -->|"[LAB-101] Case Update\nOML^O21"| PAWM
DAWM -->|"[LAB-102] Place Work Order\nOML^O21"| PAWM
PAWM -->|"[LAB-103] Accept Work Order\nOML^O21"| DAWM
IMA -->|"[LAB-104] Image Availability Notification\nOML^O21"| PAWM
IMA -->|"[LAB-104] Image Availability Notification\nOML^O21"| DAWM
style PAWM fill:#e6e6e6,stroke:#666666,color:#1a1a1a
style IMA fill:#cccccc,stroke:#666666,color:#1a1a1a
style DAWM fill:#d9d9d9,stroke:#666666,color:#1a1a1a
Figure 1:XX.1-1: DPOW Actor Diagram
Table 1:XX.1-1 lists the transactions for each actor directly involved in the DPOW Profile. To claim compliance with this profile, an actor shall support all required transactions (labeled "R") and may support the optional transactions (labeled "O").
Table 1:XX.1-1: DPOW Profile - Actors and Transactions
| Actor | Transaction | Optionality | Reference |
|---|---|---|---|
| Physical Asset Workflow Manager (PAWM) | Physical Asset Registration [LAB-100] | R | PaLM TF-2: 3.LAB-100 |
| Case Update [LAB-101] | R | PaLM TF-2: 3.LAB-101 | |
| Place Work Order [LAB-102] | O (Note 1) | PaLM TF-2: 3.LAB-102 | |
| Accept Work Order [LAB-103] | O (Note 1) | PaLM TF-2: 3.LAB-103 | |
| Image Availability Notification [LAB-104] | R | PaLM TF-2: 3.LAB-104 | |
| Digital Asset Workflow Manager (DAWM) | Physical Asset Registration [LAB-100] | R | PaLM TF-2: 3.LAB-100 |
| Case Update [LAB-101] | R | PaLM TF-2: 3.LAB-101 | |
| Place Work Order [LAB-102] | O (Note 1) | PaLM TF-2: 3.LAB-102 | |
| Accept Work Order [LAB-103] | O (Note 1) | PaLM TF-2: 3.LAB-103 | |
| Image Availability Notification [LAB-104] | R | PaLM TF-2: 3.LAB-104 | |
| Image Manager / Image Archive (IMA) | Image Availability Notification [LAB-104] | R | PaLM TF-2: 3.LAB-104 |
Note 1: Place Work Order [LAB-102] and Accept Work Order [LAB-103] are optional as a group (the Additional Work Order Option). If an actor implements either transaction, it SHALL implement both. See Section 1:XX.2.
Note 2: For [LAB-100], the DPOW-SLIDE^IHE flavour is the minimum required. Support for DPOW-SPECIMEN^IHE and DPOW-BLOCK^IHE flavours is optional and governed by the Specimen Registration Option and Block Registration Option respectively. See Section 1:XX.2.
The actors in this profile are described in more detail in the sections below.
The PAWM assumes the following interoperability responsibilities in the context of the DPOW workflow:
This actor is frequently associated to a Laboratory Information System (LIS).
The DAWM assumes the following interoperability responsibilities:
This actor is realised by a digital pathology workflow orchestrator, usually a LIS or a PACS.
The IMA stores digital pathology images and notifies the PAWM and DAWM of image availability and status changes. Refer to the IHE PaLM DPIA profile for the full definition of this actor's responsibilities in the image acquisition workflow. In the context of DPOW, the IMA:
The transactions in this profile are specified in detail in Volume 2:
Options that may be selected for each actor in this profile are listed in Table 1:XX.2-1. Dependencies between options, when applicable, are specified in notes.
Table 1:XX.2-1: DPOW - Actors and Options
| Actor | Option Name | Transaction / Flavour | Reference |
|---|---|---|---|
| Physical Asset Workflow Manager (PAWM) | Specimen Registration Option | [LAB-100] DPOW-SPECIMEN^IHE |
Section 1:XX.2.1 |
| Block Registration Option | [LAB-100] DPOW-BLOCK^IHE |
Section 1:XX.2.2 | |
| Additional Work Order Option | [LAB-102] + [LAB-103] | Section 1:XX.2.3 | |
| Digital Asset Workflow Manager (DAWM) | Specimen Registration Option | [LAB-100] DPOW-SPECIMEN^IHE |
Section 1:XX.2.1 |
| Block Registration Option | [LAB-100] DPOW-BLOCK^IHE |
Section 1:XX.2.2 | |
| Additional Work Order Option | [LAB-102] + [LAB-103] | Section 1:XX.2.3 |
The DPOW-SLIDE^IHE flavour of [LAB-100] is the minimum required for both PAWM and DAWM. It covers the most common interoperability scenario - slide-level registration for digital pathology workflows.
The Specimen Registration Option adds support for specimen/container registration (DPOW-SPECIMEN^IHE). Laboratories that perform accessioning-level integration with the DAWM should implement this option. Both actors (PAWM and DAWM) SHALL declare the same set of [LAB-100] options to ensure that every flavour sent by the PAWM can be received and processed by the DAWM.
The Block Registration Option adds support for block/cassette registration (DPOW-BLOCK^IHE). Laboratories that expose grossing workflow data to the DAWM should implement this option.
The Additional Work Order Option covers Place Work Order [LAB-102] and Accept Work Order [LAB-103] as an interdependent group. An actor claiming the Additional Work Order Option SHALL implement both transactions. Neither is meaningful without the other.
An actor from this profile SHALL implement all of the required transactions in this profile in addition to all of the requirements for the grouped actor (Column 2).
Table 1:XX.3-1: DPOW - Required Actor Groupings
| DPOW Actor | Actor(s) may be grouped with | Reference |
|---|---|---|
| Physical Asset Workflow Manager (PAWM) | IHE PaLM DPIA / Acquisition Manager | IHE PaLM DPIA |
| Image Manager / Image Archive (IMA) | IHE PaLM DPIA / Image Manager / Image Archive | IHE PaLM DPIA |
| All DPOW actors | IHE ITI CT / Time Client | ITI TF-1: 7.1 |
All actors in DPOW SHOULD be grouped with the Consistent Time (CT) Profile - Time Client Actor to ensure consistent timestamps across audit logs and messages.
DPOW relies on the hierarchical physical asset model established in the Proposed DICOM Pathology Data Model of the IHE PaLM DPIA profile:
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graph TD
P["Patient"]
C["Case"]
S["Gross Tissue\n-> registered via [LAB-100]\nMSH-21: DPOW-SPECIMEN^IHE"]
B["Block / Cassette\n-> registered via [LAB-100]\nMSH-21: DPOW-BLOCK^IHE"]
G["Glass Slide\n-> registered via [LAB-100]\nMSH-21: DPOW-SLIDE^IHE"]
D["Digital Image\n-> notified via [LAB-104]"]
P --> C --> S --> B --> G --> D
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style B fill:#dedede,stroke:#666666,color:#1a1a1a
style G fill:#d9d9d9,stroke:#666666,color:#1a1a1a
style D fill:#cccccc,stroke:#666666,color:#1a1a1a
Figure 1:XX.4.1-1: DPOW Physical Asset Hierarchy
Each level in this hierarchy is registered and broadcast by the PAWM as physical assets are created in the laboratory. The DAWM receives these registrations and builds a case-level view for workflow coordination.
The DAWM may request additional work at any level of the hierarchy using [LAB-102], and the PAWM responds with the result using [LAB-103]. Image availability at the bottom of the hierarchy is notified by the IMA using [LAB-104]. Case-level status is synchronised between PAWM and DAWM at any point during the workflow using [LAB-101].
Use cases are informative, not normative; "SHALL" language is not used in this section.
Upon receipt of a surgical specimen, the PAWM registers the specimen (container) and broadcasts its availability to the DAWM. This allows the DAWM to create a placeholder for the case and begin tracking the physical asset through the pathology workflow.
DPOW-SPECIMEN^IHEKey parameters:
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sequenceDiagram
participant PAWM as PAWM
participant DAWM as DAWM
PAWM->>DAWM: OML^O21 [LAB-100] MSH-21: DPOW-SPECIMEN^IHE<br/>Specimen registered<br/>(SPM-30: accession, SPM-8: source site SCT)
Note over DAWM: Case placeholder created
DAWM-->>PAWM: ORL^O22 (AA)
During the grossing process, a histotechnologist creates tissue blocks from the received specimen. Each block is registered by the PAWM and broadcast to the DAWM, updating the case view with the new physical assets.
DPOW-BLOCK^IHEKey parameters:
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sequenceDiagram
participant PAWM as PAWM
participant DAWM as DAWM
loop For each block created during grossing
PAWM->>DAWM: OML^O21 [LAB-100] MSH-21: DPOW-BLOCK^IHE<br/>Block registered<br/>(SPM-2: block ID, SPM-3: parent specimen ID)
Note over DAWM: Case view updated with new block
DAWM-->>PAWM: ORL^O22 (AA)
end
Glass slides are created from blocks. Each slide (stained or unstained) is registered by the PAWM and broadcast to the DAWM. Unstained slides create placeholders indicating that a stained slide is pending or forthcoming.
DPOW-SLIDE^IHEKey parameters:
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sequenceDiagram
participant PAWM as PAWM
participant DAWM as DAWM
PAWM->>DAWM: OML^O21 [LAB-100] MSH-21: DPOW-SLIDE^IHE (ORC-1: NW)<br/>Slide registered - unstained<br/>(SAC-48: WSI, no OBX stain)
Note over DAWM: Placeholder created<br/>(slide pending staining)
DAWM-->>PAWM: ORL^O22 (AA)
Note over PAWM: Slide proceeds to stainer
PAWM->>DAWM: OML^O21 [LAB-100] MSH-21: DPOW-SLIDE^IHE (ORC-1: XO)<br/>Slide updated - stained<br/>(OBX-5: H&E stain SCT codes)
Note over DAWM: Placeholder updated<br/>with stain metadata
DAWM-->>PAWM: ORL^O22 (AA)
At key points in the case lifecycle, either the PAWM or DAWM sends a case-level update to the other actor to keep the case synchronised. An update may carry any case-level data; workflow-status milestones are the most common example. Physical workflow milestones (e.g., grossing complete, pre-analytical complete) are sent by the PAWM. Digital workflow events (e.g., pathologist assigned, reading in progress, case verified) are sent by the DAWM.
DPOW-CASE-UPDATE^IHEKey parameters:
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sequenceDiagram
participant PAWM as PAWM
participant DAWM as DAWM
PAWM->>DAWM: OML^O21 [LAB-101] (ORC-1: NW)<br/>Case registered (Requested)
DAWM-->>PAWM: ORL^O22 (AA)
Note over PAWM: Examination in progress
PAWM->>DAWM: OML^O21 [LAB-101] (ORC-1: SC, ORC-5: IP)<br/>Examination started (InProgress)
DAWM-->>PAWM: ORL^O22 (AA)
Note over PAWM: Examination completed, awaiting reading
PAWM->>DAWM: OML^O21 [LAB-101] (ORC-1: SC, ORC-5: CM)<br/>Examination completed
DAWM-->>PAWM: ORL^O22 (AA)
Note over DAWM: Report signed as final
DAWM->>PAWM: OML^O21 [LAB-101] (ORC-1: SC, ORC-5: CM, ORC-25: Final)<br/>Report final
PAWM-->>DAWM: ORL^O22 (AA)
A pathologist or histotechnologist, via the DAWM, requests additional work on a physical asset - such as immunohistochemistry (IHC), FISH, or a recut of an existing block. The DAWM places the order to the PAWM, which fulfils it and responds.
[LAB-103] is sent once, when the PAWM has accepted and fulfilled the order: ORC-5 = CM, with SPM-2.1 carrying the placer identifier and SPM-2.2 the filler-assigned identifier of the new asset. If the PAWM cannot accept or fulfil the order, that is conveyed in the ORL^O22 acknowledgement to [LAB-102] (ORC-1 = UA) and no [LAB-103] is sent.
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sequenceDiagram
participant DAWM as DAWM
participant PAWM as PAWM
DAWM->>PAWM: OML^O21 [LAB-102] (ORC-1: NW)<br/>Place Work Order<br/>(e.g., IHC Ki-67 on Block A1)<br/>(SPM-3: parent block ID, SPM-2.1: DAWM temp ID)
PAWM-->>DAWM: ORL^O22 (accepted: ORC-1 OK / cannot fulfil: ORC-1 UA)
Note over PAWM: PAWM accepts and fulfils the order<br/>(technician cuts slide, applies stain)
PAWM->>DAWM: OML^O21 [LAB-103] (ORC-5: CM)<br/>Work order accepted and fulfilled<br/>(SPM-2.1: placer ID, SPM-2.2: filler-assigned slide ID)
DAWM-->>PAWM: ORL^O22 (AA)
Note over PAWM: New slide created -> LAB-100 follows
PAWM->>DAWM: OML^O21 [LAB-100] MSH-21: DPOW-SLIDE^IHE<br/>New slide registered
DAWM-->>PAWM: ORL^O22 (AA)
When a whole slide image becomes available in the IMA (following acquisition via DPIA), the IMA notifies the PAWM and DAWM. This enables the DAWM to update the case view and trigger further workflow steps. A subsequent Case Update [LAB-101] with ORC-5: CM (all expected images imported) may follow.
[LAB-104] is naturally linked to the IHE DPIA transaction "Completion Document Stored".
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sequenceDiagram
participant IMA as IMA
participant PAWM as PAWM
participant DAWM as DAWM
Note over IMA: WSI acquisition complete
IMA->>PAWM: OML^O21 [LAB-104]<br/>Image available<br/>(SPM-2: slide ID, SPM-18: scan DT, SPM-20: Y)
IMA->>DAWM: OML^O21 [LAB-104]<br/>Image available<br/>(SPM-2: slide ID, SPM-18: scan DT, SPM-20: Y)
Note over DAWM: Case updated - image available
An image may need to be removed or flagged from the case view - for example, a 20x scan deemed insufficient is superseded by a 40x rescan. The IMA notifies the PAWM and DAWM of the removal or de-association using SPM-20 = N.
Note: The notification is sent only when there are no more slide images associated to a physical asset.
DPOW transactions convey Personal Health Information (PHI). Implementers SHALL consider the security and privacy environment in which DPOW is deployed. The following forms of attack, at minimum, should be considered: eavesdropping, replay, message insertion, deletion, modification, man-in-the-middle, and denial of service. DPOW is expected to be deployed between systems within a single organisation on an internal network; the groupings below provide the baseline countermeasures.
All actors in DPOW SHOULD be grouped with the Consistent Time (CT) Profile - Time Client Actor to ensure a consistent system clock across all actors for audit logging and message timestamp accuracy.
The IHE ITI Audit Trail and Node Authentication (ATNA) Profile SHOULD be implemented by all actors to protect node-to-node communication and produce an audit trail of PHI-related actions. Where an actor is grouped with an ATNA Secure Node or Secure Application, it SHALL record the relevant audit events for the DPOW transactions it supports.
When sending information between clinical documentation and laboratory systems, it may be necessary to firmly establish the identity of the users performing each action. The Cross-Enterprise User Assertion (XUA) Profile MAY be utilised for this purpose.
Note: XUA is recommended over IUA for DPOW, as DPOW is expected to be deployed between systems within the same organisation on the same internal network.
This section is informative, not normative. It is intended to put this profile in context with other profiles.
DPOW is designed to operate in conjunction with the IHE PaLM DPIA profile. DPIA covers the acquisition of digital images from physical glass slides. DPOW covers the upstream specimen registration workflow and the downstream image availability notification. Implementers should implement both profiles to achieve a complete end-to-end digital pathology workflow.
The IMA actor in DPOW corresponds to the Image Manager / Image Archive actor in DPIA.
The Invoke Image Display (IID) profile MAY be used in conjunction with DPOW to enable non-image-aware systems (such as the PAWM) to invoke display of a pathology study in the DAWM or an associated image viewer.