HL7 vs FHIR in the oncology context
Classic HL7 v2 still dominates the interfaces that run oncology operations: ADT, orders, results, scheduling, and charges. FHIR concepts are emerging but are not yet the backbone of most oncology environments. Set realistic expectations about FHIR maturity before scoping any project around it.
Core interfaces in a radiation oncology environment
| Interface | Direction | Standard | What it carries |
|---|---|---|---|
| ADT | EHR to OIS | HL7 v2 | Patient demographics and encounters |
| Orders | EHR to OIS | HL7 v2 | Orders and order updates |
| Results / docs | OIS to EHR | HL7 v2 | Results and documentation back to the record |
| Scheduling | Bidirectional | HL7 v2 | Appointment data |
| Charges | OIS to billing | HL7 v2 | Charges to the revenue cycle system |
| Imaging / RT | Various | DICOM / DICOM RT | Imaging and treatment data touchpoints |
Data mapping considerations
- Patient identity and MRN handling across identity domains.
- Dictionaries and code sets aligned on both sides.
- Episode and encounter alignment.
- Charge codes mapped to the billing system.
Common failure points
- Identity mismatches and duplicates.
- Dropped or stuck messages.
- Mapping gaps between systems.
- Timing and sequencing issues such as out-of-order ADT.
- Charge logic mismatches.
- Silent failures that no one is monitoring.
A testing approach for oncology interfaces
- Build a test matrix with one row per message type and test case.
- Define expected versus actual for each.
- Test edge cases: cancellations, updates, and merges.
- Validate end to end, including charges.
- Add monitoring and alerting before go-live, not after.
Common questions
- Do you work directly in our interface engine?
- Engagements vary. We frequently work alongside your interface team to analyze, map, test, and troubleshoot. Direct engine access depends on your environment and your access policies.
- Is this official integration documentation?
- No. This is a vendor-neutral working guide. Exact message profiles and capabilities depend on system versions and local configuration. Always validate against your environment.
GlobalSABT is an independent consulting company and is not affiliated with, certified by, or endorsed by Epic, Varian, Elekta, Oracle Cerner, or any other system vendor. Product names describe environments only. Do not submit Protected Health Information, patient identifiers, medical record numbers, or confidential clinical data through this form.