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

Significant Changes and Issues

Significant Changes

Significant Changes from the Initial Draft

Revision 0.1 (Draft for Public Comment) incorporates the outcomes of the ECDP 2026 meeting (16 June 2026):

• Actors renamed. Laboratory Specimen Manager (LSM) -> Physical Asset Workflow Manager (PAWM); Digital Pathology Workflow Manager (DPWM) -> Digital Asset Workflow Manager (DAWM). Adopted informally at ECDP 2026; no formal ballot has taken place.
• Transactions renumbered from letter-based placeholders (LAB-T/U/V/W/X/Y/Z) to the numeric range LAB-100 … LAB-104, chosen to avoid collision with the DPIA transactions expected to follow from LAB-82. Numbers remain provisional pending DCC assignment.
• Physical asset registration collapsed into a single transaction Physical Asset Registration [LAB-100], with the asset type (specimen / block / slide) distinguished by the MSH-21 profile identifier (DPOW-SPECIMEN^IHE, DPOW-BLOCK^IHE, DPOW-SLIDE^IHE) rather than three separate transactions.
• New bidirectional Case Update [LAB-101] transaction for case-level synchronisation (case status and other case-level data) between PAWM and DAWM.
• Digital slide management / archival (a DAWM-initiated request to the IMA) was considered but deferred; its conveyance is unsettled. See Issue 8.
• HL7 version fixed to v2.5.1 with named pre-adoptions (PRT, ORC-34, SAC-48, ORC-38), replacing the earlier v2.5.1-vs-v2.9.1 ambiguity (Issue 3).
• Preparation metadata moved to OBX-5 (fixative, embedding medium, stain), aligning with DPIA and deprecating SPM-6.

Issues

Submit an Issue

IHE welcomes issues from the community. Issues may be submitted through the IHE PaLM Public Comment form, or, for those with GitHub access, as New Issues on the DPOW GitHub repository.

As issues are submitted they are managed on GitHub Issues, where discussion and workarounds may be found. When critical, they are processed using the normal IHE Change Proposal management and balloting. As soon as a Change Proposal is approved, it carries the same weight as a published Implementation Guide (i.e., it is testable at an IHE Connectathon from the time it is approved, even if it will not be integrated until several months later).

Open Issues

Issue 4 - Unstained Slide Handling

Working with pre-existing or newly created unstained slides raises two related questions. First, within DPOW, it is unclear whether [LAB-100] (with DPOW-SLIDE^IHE) covers both ordering a new slide and registering an unstained slide, and how the slide identifier lifecycle is managed across the staining process - specifically whether a (re)stained slide retains its SPM-2 identifier or receives a new one, and how lineage (SPM-3) is maintained. Second, across profiles, it is unclear how unstained slides are modelled in DPIA and whether DPOW's handling (registration via [LAB-100] with DPOW-SLIDE^IHE, SPM-6 absent) aligns with DPIA expectations.

Action Point: Define the SPM-2 identifier lifecycle across the unstained-to-stained transition and how SPM-3 lineage is maintained, and align DPOW's treatment of unstained slides with DPIA.

Issue 5 - AI-Generated Derived Images

Derived images generated by AI systems from an existing WSI are out of scope for DPOW Rev 0.1. Should they be addressed in a future revision, the actor roles and transaction trigger would need to be defined - in particular, which actor sends [LAB-104] for an AI-derived image and whether the IMA is the appropriate source.

Action Point: Consider AI-derived image notifications in a future DPOW revision or a separate supplement; no action is required for the current release.

Issue 6 - Transaction Number Registration

All transaction numbers in this profile (LAB-100 through LAB-104) are pending formal verification and assignment by the IHE Domain Coordination Committee (DCC). LAB-100+ has been selected as the target range to avoid collision with DPIA transactions, which are expected to follow from LAB-82.

Action Point: Submit transaction registration request to IHE IT Infrastructure domain coordinator at the appropriate stage of the DPOW lifecycle.

Issue 8 - Image Lifecycle Management and Digital Slide Management

Two related image-lifecycle capabilities are deferred to a future DPOW revision:

• Digital slide management / archival - a DAWM-initiated request to the IMA to remove or archive a specific stored WSI (e.g., superseding an insufficient scan, removing a faulty image, or offloading to cold storage). This was drafted as a transaction for Rev 0.1 but removed because its conveyance is unsettled: whether to reuse OML^O21 or define a dedicated message needs further analysis.
• Broader ILM - PAWM-initiated image removal, image rehydration, and automated lifecycle orchestration.

Action Point: Decide whether DPOW should define a DAWM-initiated digital slide management / archival transaction and, if so, how to convey it (reuse OML^O21 or a dedicated management transaction). Address PAWM-initiated removal and rehydration. Coordinate with the PaLM TC and the HL7 Order Management WG.

Issue 9 - OUL^R22 for Result-Carrying Image Notifications

OML^O21 is mandated for [LAB-104] in the Public Comment release because LIS providers prefer it, for consistency with the other DPOW transactions. From a standards standpoint, however, OUL^R22 may make more sense when additional result content needs to be conveyed alongside the image availability notification (e.g., slide image thumbnail, QC status, AI analysis result), as it is the natural fit for unsolicited observations. Whether OUL^R22 should be permitted as an alternative message type in [LAB-104] will be reviewed at Trial Implementation based on Connectathon experience.

Action Point: Evaluate OUL^R22 as an optional message type in [LAB-104] at Trial Implementation. Define which result types (thumbnail, QC, AI result) would require it.

Issue 10 - ORC-25 Case Status Value Set

The ORC-25 case status value set defined in the Case Update [LAB-101] transaction is a working draft produced at ECDP 2026 (16/06/2026) and requires broader community consensus before adoption. It is published as the DPOW Case Status FHIR CodeSystem and ValueSet (dpow-case-status), but still requires review and formal adoption by the PaLM TC, and registration of an OID for the code system, before Trial Implementation.

Action Point: Present the DPOW Case Status value set at the next PaLM TC meeting for review and formal adoption, and register an OID for the DPOW Case Status code system (replacing the informal 99DPOW local code system).

Closed Issues

Issue 1 - Image Notification Message Type

For the Image Availability Notification transaction [LAB-104], OML^O21 is the selected message type for the Public Comment release. OUL^R22 has been deferred to Open Issue 9 for consideration at Trial Implementation.

Issue 2 - LAB-V: Additional Order Response Transaction

LAB-V is not required as a separate transaction. [LAB-103] (Accept Work Order) conveys the PAWM's acceptance and fulfilment of a work order in a single message (ORC-5 = CM, SPM-2.2 populated with the filler-assigned identifier). A work order the PAWM cannot fulfil is rejected in the ORL^O22 acknowledgement to the [LAB-102] request (ORC-1 = UA), so no separate response transaction is needed.

Issue 3 - HL7 Version

This profile targets HL7 v2.5.1. Pre-adoptions from later versions used in this profile are:

• SAC-48 (Container Material, v2.9.1) - pre-adopted to support the WSI value.
• PRT (Participation, v2.7+) - pre-adopted for pathologist identification; v2.5.1 fallback is OBR-32 for reading pathologist.
• ORC-34 (Order Workflow Profile, v2.9) - pre-adopted to carry the workflow routing profile identifier (IMAGE, PACS-WORKFLOW, PACS-REPORTING).
• ORC-38 (Filler Order Group Number, v2.9) - pre-adopted to carry the case accession number for alignment with DPIA (see Closed Issue 7).

Issue 7 - Accession Number Field: SPM-30 and ORC-38

DPOW retains SPM-30 (Accession ID) as a carrier of the case accession number and, for alignment with the DPIA profile (which uses ORC-38, Filler Order Group Number, per DPIA Closed Issue 14B), additionally populates ORC-38 with the same accession value. Both fields are carried; no existing field is removed. ORC-38 is a pre-adoption from HL7 v2.9 (see Closed Issue 3).