MII IG Pathologie-Befund EN v2026

Terminologies

LOINC terms from the DOC.* class or the Doc scale are used to code the entire pathology report as well as the grouper observations.

The generic observations themselves should be coded as accurately as possible as they were observed, i.e., on which sample type, with which method, etc.

The numerous possibilities for describing observations with code-value pairs are limited to two (three) basic options for non-numeric observation results:

1. The Observation.code represents the type of observation, and the Observation.value represents the non-numeric observation value.

• Observation.code: Extent of extraprostatic tumor spread
• Observation.valueCodebleConcept: focal

2. The Observation.code is expressed by a possibility that does not encode the action of the observation, but rather represents a statement about a finding. Thus, the Observation.value is a qualifier that encodes the presence or absence of the finding.

• Observation.code: Perineural sheath invasion
• Observation.valueCodebleConcept: Yes/No indicator of Observation.valueBoolean

3. The Observation.code is represented by a statement about a finding, as in 2. The Observation.value is omitted.

• Observation.code: Perineural sheath invasion
• Observation.valueCodebleConcept:
• Observation.dataAbsentReason: not-applicable

For the first option, all LOINC terms of the types "Lab" and "Clinical" are available. If no suitable LOINC code is available, a SNOMED-CT code is used, which is derived from the hierarchy axis |363787002 (Observable entity)| or |386053000 (Evaluation procedure)|. The observation.values ​​are preferably SNOMED-CT codes or corresponding LOINC answer codes.

For the second option, the Observation.code is preferably a SNOMED-CT code from the hierarchy axes |404684003 (Clinical finding)|, |413350009 (Finding with explicit context)|, or |272379006 (Event)|. The Observation.value is preferably represented by the SNOMED-CT axis |362981000 (Qualifier value)|. Postcoordinated SNOMED-CT expressions should be avoided.

For the third option, a SNOMED-CT code from the above-mentioned hierarchy axes should preferably be used. An Observation.dataAbsentReason.value of the missing Observation.value should be used to indicate why this value is missing.

If no suitable LOINC terms or SNOMED-CT codes can be found, other standardized code systems (e.g., HL7 V2.x or V3, ICD-10, ICD-11, ICD-O-3, ADT/GEKID) are preferable to codes from local code systems.

TODO: Add a figure (Principle of joint use of LOINC and SNOMED-CT, https://confluence.ihtsdotools.org/display/DOCLOINC/5.2.7+Practical+Uses+of+Part+Maps+and+Expression+Associations, Chapter 5.2.7) or https://confluence.ihtsdotools.org/display/SCCDP/General+background+documentation+and+information?preview=%2F146874780%2F174689714%2FGuidelines+for+using+LOINC+and+SNOMED+CT+Together.pdf

For synoptic reports on tumors, based on ICCR protocols, the SNOMED CT Clinical Implementation Guide for Cancer Synoptic Reporting (https://confluence.ihtsdotools.org/display/DOCCANSIG/SNOMED+CT+Clinical+Implementation+Guide+for+Cancer+Synoptic+Reporting) should be considered.

The units of measurement must be specified in UCUM units so that the results can be converted into one another. Validators can be used to ensure that the units used are valid.

SNOMED-CT is also used to code specimens and procedures.

Stainings

The following approach is recommended for staining procedures:

• Histological and cytological stainings can be performed in SCT either as a precoordinated procedure (e.g., all children of 127790008) or as a combination of staining process (127790008) and the dyes used (all children of 397165007 or 45389009) can be coded as an additive (substance). A staining process can be mapped using Specimen.processing.procedure, while the associated staining substances would be mapped using Specimen.processing.additive via a reference to one or more substance resources.

• For immunohistochemical staining, so far only a few precoordinated concepts are available in SCT. Here, too, the combination of dyeing process 406867009 or 13269000 with the antibodies/antigens and chromogens as .substance or ingredient.substance.

In addition, the following can be coded in a post-coordinated staining process:

• Staining process(procedure):usingSubstance=dye or =antibody
• Staining process(procedure):directSubstance=target antigen
• or a combination of these codes

However, with post-coordinated codes, it should be noted that they are difficult to evaluate without a suitable terminology server. For this reason, our recommendation would be to first transfer the relationships between staining processes and their respective staining substances to the FHIR information model and map them using .processing.procedure and .processing.additive.

For in situ hybridizations, PCR tests, methylation assays, and NGS analyses, terminological harmonization should be achieved through the corresponding profiles of the "Molecular Tumor Board" core dataset (KDS).

ValueSets Module

In addition to the above and other international terminologies (ICD-O-3 and UICC-TNM), the Pathology Reports module defines its own ValueSets. Please note that all ValueSets do not include expansion. This must be performed using a terminology server before use.

In addition, several data elements in the FHIR resources are encoded using HL7 V2.x codes.