GDT interface for skin-analysis reports, how the integration with your practice software works

A medical practice rarely works with just one system. Patient master data lives in the practice management system (PVS), lab data comes back from the laboratory, image findings from devices ideally land directly in the patient record. The interface that holds this world together in German healthcare is GDT, "Gerätedatentransfer" (device data transfer). We explain how this plays together with skin-analysis software like Dermalia and what steps are pending for a full PVS integration.

What GDT is and where it comes from

GDT (Gerätedatentransfer) is an interface specification maintained by the Quality Ring for Medical Software (QMS) for data exchange between practice management systems and medical devices. The standard is text-based, documented and freely available. The current version GDT 3.5 was published in March 2024 in German and English and is the reference for any new integration.

GDT belongs to the family of xDT standards (GDT, BDT, LDT, KVDT). Each addresses a specific handover context, GDT specifically the device-to-PVS path. Records are defined as plain ASCII/Latin-1 text files; each field is addressable through a four- or five-digit numeric identifier.

How the data flow looks in practice

GDT is bidirectional and follows this flow in the skin-analysis practice:

1. PVS sends patient data to the device software: first name, last name, date of birth, sex, patient ID, optionally health insurance. Record used: 6302 (request examination data).
2. Practice staff trigger the capture: the scan is performed on the skin scanner, the software has the patient data pre-filled, the assistant types nothing.
3. Report is created and sent back to the PVS: as record 6310 (transmit report). Content can be structured report text, a PDF attachment, or a URL to the online report.
4. PVS stores the report in the chart: the entry appears in the patient record as an examination entry with date, examiner and optional attachment.

Practical value: the assistant does not double-enter, reports land in the chart automatically, patient identity stays consistent across PVS and report software.

Which PVS systems typically support GDT

In Germany, almost all common practice systems. The largest vendors with active GDT support are medatixx, T2med, MEDISTAR, x.concept, Quincy PVS, Albis, Tomedo, MCS, Frey ADS-Praxis. Dental systems like evident and CHARLY also have GDT implementations. For hospitals (KIS systems), integration is typically via HL7 instead of GDT, that is a different standard.

A practical note: GDT implementations vary between PVS vendors in the supported records and sub-versions. Integration with medatixx may mean an update of the GDT mapping configuration on the practice side; with T2med possibly a licence question. Before rolling out to multiple practices we recommend a pilot configuration with the concrete PVS of the first practice.

Status of the Dermalia integration

Dermalia currently runs as a standalone patient-report layer alongside the PVS. The practice uses our web app for QR scan and report dispatch, the report lives in our dashboard and is delivered to patients via email link. A GDT interface is on the roadmap, the concrete timing depends on the pilot-practice configuration.

What a first integration involves, in overview:

• GDT record definition for Dermalia (which fields go in, which come out)
• Mapping of score values to a textual report form (PDF attachment is the pragmatic default)
• Configuration in the pilot practice's PVS (paths, triggers, receive directory)
• Test loop with pilot patients before production use

A practice needing a concrete integration with a specific PVS should mention this in the consultation early. We can scope the effort realistically; for the first pilot practices a GDT integration is cost- and priority-relevant.

Alternative: KIM and TI integration

The German Telematics Infrastructure (TI) and the KIM service (Kommunikation im Medizinwesen) go a step further and provide secure end-to-end communication between practices, hospitals and pharmacies. For report handover to the treating practice, KIM is an option; for the device-to-PVS local connection GDT remains the pragmatic choice. Both paths are not mutually exclusive, they address different handover points.

Sources and further reading

• Quality Ring Medical Software (QMS), GDT specification: qms-standards.de/gdt-schnittstelle
• GDT 3.5 specification (freely available in German and English, March 2024): qms-standards.de
• medatixx, explanation of the GDT interface in practice: medatixx.de
• Gematik, Telematics Infrastructure and KIM service (overview): gematik.de

As of May 2026. This article describes the GDT standard and the current Dermalia integration status. Concrete integration steps we discuss in the onboarding call.