RT Genomic Attestation Vocabulary

Genomic attestation claim vocabulary for radiation oncology.

12 min read diagramsUpdated 2026-05-07docs/architecture/bia-rt-1-genomic-attestation-vocabulary.md

Field	Value
Spec ID	BIA-RT-1
Status	Draft v0.1
Issuer authority	Ever Medical Technologies
Anchored to	BIA-1 (`did:bio` core spec)
Consumed by	medOS `oncology-rt` module · Ever HealthWallet ClaimGuard · partner FHIR systems
Companion spec	BIA-RT-2 (FHIR `EverOncologyRTCarePlan` profile)
Date	2026-05-07

1. Purpose & scope

BIA-RT-1 defines a closed, stable vocabulary of 16 claim types that a did:bio wallet can attest about its subject, sufficient to drive radiation oncology clinical decisions across the five RT-relevant genomic entry points:

Hereditary cancer syndromes (germline)
Tumor predictive markers (somatic)
Radiosensitivity / radioresistance signatures
Pharmacogenomics for concurrent chemoradiation
Second-malignancy and late-effect risk

The vocabulary is deliberately small. Variant-level nomenclature (HGVS, dbSNP, ClinVar) evolves quarterly; clinical conclusions are stable across years. BIA-RT encodes the latter.

This document is normative. Keywords MUST, MUST NOT, SHOULD, SHOULD NOT, MAY follow RFC 2119.

2. Design principles

Claims, not data. Consumers receive verifiable clinical conclusions with provenance — never raw VCFs, never population variant data. The genome stays in the patient’s wallet.

Selective disclosure. Each claim in a credential is independently disclosable via BBS+ blinded signatures. A radiation oncologist requesting only tumor_hpv_status learns nothing about hereditary risk.

Verifiable provenance. Every claim carries: issuer DID, issuance timestamp, evidence reference, confidence class, revocation pointer.

Composable with FHIR. Each claim maps to one or more Reference targets inside the medOS oncology-rt-careplan profile. Claims do not replace FHIR Observation resources; they are an attestation layer above them.

Stable across re-testing. When a panel is re-interpreted, the new credential supersedes the old via the issuance chain. Plans hold credential references, not embedded values, so re-issuance updates the plan without rewriting it.

3. Credential envelope

Standard W3C VC v1.1 with BIA-RT context, BBS+ signature for selective disclosure.

{
  "@context": [
    "https://www.w3.org/2018/credentials/v1",
    "https://schema.ever.med/bia/v1",
    "https://schema.ever.med/bia-rt/v1"
  ],
  "type": ["VerifiableCredential", "BIAGenomicAttestation"],
  "id": "urn:uuid:<credential-id>",
  "issuer": "did:bio:lab:<lab-did>",
  "issuanceDate": "2026-04-15T10:00:00Z",
  "expirationDate": "2031-04-15T10:00:00Z",
  "credentialStatus": {
    "type": "RevocationList2020Status",
    "id": "https://revocation.ever.med/lab/<lab-did>/list#42",
    "revocationListIndex": "42",
    "revocationListCredential": "https://revocation.ever.med/lab/<lab-did>/list"
  },
  "credentialSubject": {
    "id": "did:bio:patient:<patient-did>",
    "claims": [
      { "claim_type": "germline_radiosensitivity_class", "value": "high", "...": "..." },
      { "claim_type": "tumor_hpv_status", "value": "positive", "...": "..." }
    ]
  },
  "proof": {
    "type": "BbsBlsSignature2020",
    "created": "2026-04-15T10:00:00Z",
    "verificationMethod": "did:bio:lab:<lab-did>#key-1",
    "proofPurpose": "assertionMethod",
    "proofValue": "..."
  }
}

Multiple claims MAY ride in one credential. A credential MUST NOT mix claims about different subjects.

4. Claim catalog (v0.1)

Sixteen claim types. For each: clinical use, value space, evidence requirements, JSON shape, disclosure granularity, lifetime.

4.1 — Hereditary risk (germline)

C-01 · `germline_radiosensitivity_class`

Clinical use. Drives prescription dose modification. ATM heterozygotes, AT-like phenotypes, Li-Fraumeni patients show clinically meaningful radiosensitivity. Single highest-value RT genomic claim.

Value space. high | moderate | normal | unknown

Evidence required. Underlying variant(s) catalogued with germline pathogenicity classification (ACMG-2015 or successor) OR functional radiosensitivity assay (G2 chromosomal, γ-H2AX, etc.).

{
  "claim_type": "germline_radiosensitivity_class",
  "value": "high",
  "evidence": {
    "panel_id": "lab.bumrungrad.hereditary-v3",
    "method": "NGS-germline",
    "interpretation_guideline": "ACMG-2015",
    "source_genes": ["ATM"]
  },
  "confidence": "high"
}

evidence.source_genes MAY be redacted at disclosure time via BBS+ blinding if patient consent withholds it.

Disclosure granularity. Claim level. evidence.source_genes independently redactable.

Lifetime. Lifetime of subject. Re-issued only on lab reinterpretation.

C-02 · `hereditary_cancer_syndrome`

Clinical use. Identifies syndromes that contraindicate or modify RT (Li-Fraumeni → avoid RT where possible; Fanconi anemia → severe radiosensitivity; AT homozygous → contraindication; Lynch → screening implications post-RT).

{
  "claim_type": "hereditary_cancer_syndrome",
  "value": "LFS",
  "evidence": {
    "panel_id": "lab.<id>",
    "diagnostic_criteria": "Chompret-2015"
  },
  "confidence": "high"
}

Lifetime. Lifetime.

C-03 · `germline_actionable_variant`

Clinical use. When clinical conclusion (C-01, C-02) is insufficient and the consumer needs the specific variant for variant-specific dosing, family cascade testing, or research enrolment.

Value space. Array of variant objects.

{
  "claim_type": "germline_actionable_variant",
  "variants": [
    {
      "gene": "ATM",
      "transcript": "NM_000051.4",
      "hgvs_c": "c.7271T>G",
      "hgvs_p": "p.Val2424Gly",
      "zygosity": "heterozygous",
      "classification": "pathogenic",
      "classification_source": "ClinVar:VCV000003027.5"
    }
  ],
  "evidence": { "panel_id": "lab.<id>", "reference_build": "GRCh38" }
}

Privacy note. Disclosure reveals germline identity-level information. Consent flow MUST present this as elevated disclosure with explicit purpose statement and time-bound scope.

Disclosure granularity. Per-variant. Each entry in variants[] is independently blindable.

Lifetime. Lifetime; re-issued on reinterpretation.

4.2 — Tumor predictive markers (somatic)

C-04 · `tumor_hpv_status`

Clinical use. De-escalation of dose in HPV+ oropharyngeal SCC; prognostic stratification cervical/anal.

Value space. positive | negative | not_tested; subtype optional.

{
  "claim_type": "tumor_hpv_status",
  "value": "positive",
  "subtype": "HPV-16",
  "method": "p16-IHC | ISH | HPV-PCR | NGS",
  "specimen_id": "<biospecimen-did or local id>",
  "tumor_site": "oropharynx"
}

Lifetime. Per-tumor. New primary → new attestation.

C-05 · `tumor_mgmt_methylation`

Clinical use. Glioblastoma RT response prediction; concurrent temozolomide benefit.

Value space. methylated | unmethylated | not_tested

{
  "claim_type": "tumor_mgmt_methylation",
  "value": "methylated",
  "method": "MSP | pyrosequencing | EPIC-array",
  "specimen_id": "...",
  "tumor_site": "brain.frontal_lobe"
}

Lifetime. Per-tumor.

C-06 · `tumor_actionable_alteration`

Clinical use. Influences whether RT is the right modality, sequence with systemic therapy, eligibility for RT-immunotherapy combinations.

Value space. Array of (gene, alteration, evidence_level).

{
  "claim_type": "tumor_actionable_alteration",
  "alterations": [
    {
      "gene": "EGFR",
      "alteration": "exon19del",
      "evidence_level": "OncoKB:1",
      "linked_therapy": ["osimertinib"]
    }
  ],
  "evidence": { "panel_id": "...", "specimen_id": "..." }
}

Vocabulary. Evidence levels MUST use OncoKB therapeutic levels (1, 2, 3A, 3B, 4, R1, R2) or ESCAT (I-A through V) — issuer specifies which.

Lifetime. Per-tumor.

C-07 · `tumor_msi_status`

Clinical use. Immunotherapy eligibility; rectal cancer treatment selection.

Value space. MSI-H | MSI-L | MSS | not_tested

{
  "claim_type": "tumor_msi_status",
  "value": "MSI-H",
  "method": "PCR-pentaplex | NGS | IHC-MMR",
  "specimen_id": "..."
}

C-08 · `tumor_mutational_burden`

Clinical use. Immunotherapy selection in combination with RT.

Value space. Numeric (mut/Mb) + class.

{
  "claim_type": "tumor_mutational_burden",
  "value_mut_per_mb": 14.2,
  "class": "high",
  "threshold_used": ">=10",
  "method_panel": "FoundationOne CDx",
  "specimen_id": "..."
}

4.3 — Radiosensitivity signatures

C-09 · `radiosensitivity_index`

Clinical use. Continuous predictor of intrinsic tumor radiosensitivity (RSI; Eschrich/Torres-Roca model and successors).

Value space. Numeric 0.0–1.0; lower = more sensitive.

{
  "claim_type": "radiosensitivity_index",
  "value": 0.32,
  "model_id": "RSI-10gene-v2",
  "model_provenance": "PMID:35612345",
  "specimen_id": "...",
  "research_grade": true
}

Conformance note. As of v0.1 RSI is research-grade; consumers MUST treat as advisory unless local validation completed. The research_grade: true flag is REQUIRED until vendor de-flags.

C-10 · `gard_recommendation`

Clinical use. Genomic-adjusted radiation dose recommendation derived from RSI + linear-quadratic model.

{
  "claim_type": "gard_recommendation",
  "recommended_dose_gy": 54,
  "fractionation_assumed": "2 Gy/fx",
  "gard_value": 38.7,
  "model_id": "GARD-v1",
  "research_grade": true
}

4.4 — Pharmacogenomics

C-11 · `pgx_phenotype`

Clinical use. Concurrent chemoradiation safety. DPYD for 5-FU/capecitabine (head/neck, rectal, esophageal); UGT1A1 for irinotecan; TPMT/NUDT15 for thiopurines; CYP2D6 for tamoxifen.

Value space. Array of (gene, phenotype) pairs using CPIC standard phenotype labels.

{
  "claim_type": "pgx_phenotype",
  "phenotypes": [
    { "gene": "DPYD", "phenotype": "intermediate_metabolizer", "diplotype": "*1/*2A" },
    { "gene": "UGT1A1", "phenotype": "normal_metabolizer", "diplotype": "*1/*1" }
  ],
  "evidence": { "panel_id": "...", "guideline_version": "CPIC-2024" }
}

Vocabulary. Phenotype values MUST be drawn from current CPIC phenotype standardization terms.

Lifetime. Lifetime (germline).

C-12 · `cpic_drug_recommendation`

Clinical use. Pre-resolved drug-level recommendations from PGx phenotypes, ready for prescribing decision support.

{
  "claim_type": "cpic_drug_recommendation",
  "recommendations": [
    {
      "drug_rxnorm": "5-fluorouracil",
      "recommendation": "reduce_initial_dose",
      "magnitude": "50%",
      "guideline": "CPIC-DPYD-2017-v1.3"
    }
  ]
}

A cpic_drug_recommendation claim MAY be issued by an interpretation service that consumed a pgx_phenotype claim and produced drug-level guidance — chained issuance is allowed and the chain MUST be preserved in evidence.

4.5 — Late effects / second malignancy

C-13 · `secondary_malignancy_risk_class`

Clinical use. Informs survivorship plan and (rarely) modality choice in younger patients with strong germline modifiers (e.g., TP53 + planned mantle field).

Value space. elevated | average | reduced | unknown

{
  "claim_type": "secondary_malignancy_risk_class",
  "value": "elevated",
  "modifier_genes": ["TP53"],
  "rationale_code": "germline-tp53-pathogenic",
  "confidence": "high"
}

C-14 · `tissue_late_effect_risk`

Clinical use. Per-tissue late-effect risk for survivorship: thyroid (post-cervical/mediastinal RT), breast (post-mantle RT in young women), cardiac, lung fibrosis, infertility.

{
  "claim_type": "tissue_late_effect_risk",
  "tissues": [
    { "tissue": "thyroid", "risk_class": "elevated", "modifiers": ["age_at_rt<20"] },
    { "tissue": "breast",  "risk_class": "elevated", "modifiers": ["BRCA1_germline"] }
  ]
}

4.6 — Trust chain meta-claims

C-15 · `genome_provenance`

Clinical use. Establishes the laboratory chain of custody for any clinical claim derived from sequencing. REQUIRED whenever C-01 through C-12 are issued from a sequencing-derived basis.

{
  "claim_type": "genome_provenance",
  "lab_did": "did:bio:lab:bumrungrad-genomics",
  "lab_accreditation": ["CLIA:99D2030555", "ISO15189:2022"],
  "panel_id": "lab.bumrungrad.solid-tumor-v4",
  "panel_version": "4.2.1",
  "reference_build": "GRCh38",
  "sequencing_date": "2026-04-12",
  "specimen_type": "FFPE | blood | saliva | fresh_tissue",
  "specimen_id": "<did:bio:specimen or local>"
}

C-16 · `bio_identity_binding`

Clinical use. The core BIA property. Cryptographic proof that the genome attested by C-01…C-14 is bound to the same biological identity as the wearable / biometric continuous attestation stream from BIA-1. Without this, genomic claims could be replayed against a different patient.

{
  "claim_type": "bio_identity_binding",
  "genome_commitment": "<hash commitment from BIA-1 §4.2>",
  "biometric_anchor_did": "did:bio:patient:<patient-did>",
  "binding_proof": "<ZK proof artifact>",
  "binding_method": "BIA-1-bind-v1",
  "live_attestation_recency_seconds": 3600
}

Verification. Consumers MUST verify the binding proof before relying on any C-01…C-14 claim from the same credential. A credential whose bio_identity_binding fails verification MUST be rejected even if individual claims are well-formed.

When a relying party (a medOS instance, partner system, or research portal) requests claims, the wallet presents a consent UI showing:

The relying party DID and human-readable name (resolved from registry).
The exact list of claims requested and the purpose statement.
Whether elevated-disclosure claims (C-03 in particular) are included.
Time-bound scope: one-time | duration-of-care | duration-of-research-protocol.
Re-issuance policy: whether the relying party may receive automatic updates if a newer credential supersedes.

Consent records SHOULD be themselves issuable as credentials (signed by the patient’s wallet) for audit trail. This satisfies PDPA, APPI, and HIPAA right-of-accounting requirements without further audit infrastructure.

6. Lifetimes & re-issuance

Claim	Default lifetime	Re-issued when
C-01 germline_radiosensitivity_class	Lifetime	Lab reinterpretation
C-02 hereditary_cancer_syndrome	Lifetime	Lab reinterpretation
C-03 germline_actionable_variant	Lifetime	Lab reinterpretation
C-04 tumor_hpv_status	Per-tumor	New primary
C-05 tumor_mgmt_methylation	Per-tumor	New primary
C-06 tumor_actionable_alteration	Per-tumor	New primary, on relapse re-biopsy
C-07 tumor_msi_status	Per-tumor	New primary
C-08 tumor_mutational_burden	Per-tumor	New primary
C-09 radiosensitivity_index	Per-tumor	New primary
C-10 gard_recommendation	Per-tumor	New primary, model upgrade
C-11 pgx_phenotype	Lifetime	Panel expansion
C-12 cpic_drug_recommendation	2 years	CPIC guideline update
C-13 secondary_malignancy_risk_class	Lifetime	New cumulative-dose context
C-14 tissue_late_effect_risk	Lifetime	New cumulative-dose context
C-15 genome_provenance	With underlying	With underlying
C-16 bio_identity_binding	1 year	Annually + on biometric anchor change

A new credential supersedes an older one issued by the same issuer when their claim_type and (where applicable) tumor_site / specimen_id match. The wallet SHOULD prefer the most recent valid non-revoked credential.

7. Revocation

Each credential references a revocation list (RevocationList2020 or successor). Verifiers MUST check revocation status. Recommended cache TTL: 1 hour for clinical decision contexts, 24 hours for survivorship review.

A revoked credential’s claims MUST NOT be relied upon, but historical references in plans (where the claim was relied upon at decision time) remain valid as historical record. Implementations distinguish “this claim is currently valid” from “this claim was valid when this decision was made.”

8. Conformance levels

Level	Required claims	Use case
BIA-RT Basic	C-15, C-16, plus any clinical claim	Minimum viable issuance
BIA-RT Standard	Basic + C-01, C-04, C-11	Routine RT workflow support
BIA-RT Full	All 16 claims	Comprehensive radiogenomics platform

A did:bio issuer claiming BIA-RT Standard MUST support issuance of all required claims; it MAY return not_tested values where data is unavailable but MUST issue the credential structure correctly.

9. FHIR mapping

Each claim type maps into the medOS EverOncologyRTCarePlan profile (BIA-RT-2) via the oncology-rt-genomic-attestation extension. The extension carries the credential reference (URI to wallet-resolved VC) plus a denormalized snapshot of the claim value at decision time, for clinical-record permanence.

BIA-RT claim	FHIR target in CarePlan
C-01, C-02, C-03	`extension[genomic-attestation].germlineRisk`
C-04…C-08	`extension[genomic-attestation].tumorMarkers`
C-09, C-10	`extension[genomic-attestation].radiosensitivityModel`
C-11, C-12	`extension[genomic-attestation].pharmacogenomics`
C-13, C-14	`extension[genomic-attestation].lateEffectRisk`
C-15	`extension[genomic-attestation].provenance`
C-16	`extension[genomic-attestation].identityBinding` (REQUIRED)

See BIA-RT-2 for full extension definitions and slicing.

10. Open questions for v0.2

RSI / GARD productionization. When does research_grade flag come off? Probably tied to local validation in a Thai cohort (unique opportunity given Vajira’s volume).
Family cascade testing. Should there be a claim type for “family member should be tested for X” — derived from C-02/C-03 — or is this an inference left to the consuming system?
Liquid biopsy / ctDNA monitoring. Real-time tumor burden via ctDNA may warrant a time-series claim type (tumor_burden_trajectory) in v0.2.
Polygenic risk scores. PRS for second-malignancy risk modifies C-13 — should PRS be exposed as its own claim or absorbed into the risk class?
Federated re-issuance. When a Japanese partner lab re-runs an interpretation on data originally generated in Thailand, how is the chain of custody represented? Probably a chained issuance pattern: new credential references the prior one as derivedFrom.

11. Appendix: minimum viable issuer profile

A laboratory operating as a BIA-RT issuer at Standard conformance MUST:

Hold a did:bio:lab:* DID with verifiable accreditation credential.
Maintain a signing key controlled by accredited lab director.
Operate a revocation list endpoint with 99.5% availability.
Issue credentials with valid BBS+ proofs.
Support credential re-issuance on patient request without requiring re-sequencing.
Honor patient revocation requests within 7 days.
Provide a human-readable explanation alongside each claim, accessible via a humanReadable extension field, in the patient’s language. The patient should be able to read what their own genome is being claimed to mean, in their own language, and dispute it.

End of BIA-RT-1 v0.1

1. Purpose & scope

2. Design principles

3. Credential envelope

4. Claim catalog (v0.1)

4.1 — Hereditary risk (germline)

C-01 · germline_radiosensitivity_class

C-02 · hereditary_cancer_syndrome

C-03 · germline_actionable_variant

4.2 — Tumor predictive markers (somatic)

C-04 · tumor_hpv_status

C-05 · tumor_mgmt_methylation

C-06 · tumor_actionable_alteration

C-07 · tumor_msi_status

C-08 · tumor_mutational_burden