Clinical calculator summary
Herder Model (Pulmonary Nodule)
Clinical calculator summary
Herder Model (Pulmonary Nodule)
This calculator implements the Herder et al.
Evidence-based context for fast calculator use
- Purpose:
- Estimates PET-adjusted malignancy probability for an indeterminate solitary solid pulmonary nodule using the Herder 2005 model and the full-precision Mayo probability.
- Population:
- patients undergoing thoracic oncology risk, staging, or nodule assessment
- Factors:
- Age, Smoking history, Cancer history, Solitary nodule diameter, Nodule margin, Nodule location, FDG-PET status and uptake
- Reference:
- https://pubmed.ncbi.nlm.nih.gov/16236914/
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Herder Model (Pulmonary Nodule)
years
mm
Use for one indeterminate solid pulmonary nodule. Multiple, part-solid, ground-glass, known metastatic, or already malignant nodules are outside this model.
Clinical Context & Background
This calculator implements the Herder et al. CHEST 2005 PET-adjusted model. It first calls the verified Swensen 1997 Mayo engine, then applies the published Herder transform to the full-precision Mayo probability fraction.
The source cohort contained 106 radiologically indeterminate solitary pulmonary nodules no larger than 30 mm; ages were 32-85 years and cancer within five years was excluded. This historical PET-referral model does not estimate mortality and is not a treatment mandate.
The uptake definitions and 10%/70% categories shown are a later BTS operational overlay. Primary source: https://pubmed.ncbi.nlm.nih.gov/16236914/
Formula Logic
Herder et al. 2005 PET-adjusted pulmonary nodule model:
First calculate the full-precision Swensen/Mayo malignancy probability as a fraction from 0 to 1.
Herder logit = -4.739
+ (3.691 * full-precision Mayo probability fraction)
+ (2.322 * faint FDG uptake)
+ (4.617 * moderate FDG uptake)
+ (4.771 * intense FDG uptake)
Absent uptake is the reference category (coefficient 0). Exactly one PET category is used.
Probability (%) = 100 / (1 + exp(-Herder logit)).
Later BTS bands: <10% low, 10-70% intermediate, >70% high. Exact 10% and 70% are intermediate.Reference Data
| Raw Probability | Later BTS Band | Interpretation |
|---|---|---|
| <10% | Low | Use current nodule guidance and clinical context |
| 10-70% | Intermediate | Exact 10% and 70% are included |
| >70% | High | Not a standalone treatment directive |
Clinical Workflow
Use, Interpret, And Continue The Patient Pathway
Expand for workflow guidance, limitations, examples, and related next steps.
Clinical Workflow
Use, Interpret, And Continue The Patient Pathway
Expand for workflow guidance, limitations, examples, and related next steps.
When To Use
- Use Herder Model (Pulmonary Nodule) when estimates PET-adjusted malignancy probability for an indeterminate solitary solid pulmonary nodule using the Herder 2005 model and the full-precision Mayo probability.
- Confirm that the patient, diagnosis, disease phase, and available inputs match the cited model before calculation.
How To Interpret
- Interpret the displayed result using the calculator-specific formula and reference table, spanning <10% through >70%.
- A boundary result should prompt input verification and clinical review rather than false precision.
What To Do Next
- Confirm whether the clinical question is screening eligibility, nodule malignancy, staging, or treatment prognosis and move to the corresponding thoracic pathway.
- Document the inputs, result, timing, and clinical context so the assessment can be reproduced.
Limitations
- Lung screening, nodule probability, radiology classification, and cancer staging tools answer different questions.
- The result supports clinician judgment and does not independently determine treatment.
Validated Population
patients undergoing thoracic oncology risk, staging, or nodule assessment
How to apply this result
For a representative case, verify Age, Smoking history, Cancer history, calculate the result, and confirm that its classification matches the highlighted reference band before continuing the disease-specific pathway.
Calculation verification history
Verified
Calculation verification history
Verified: Production browser revalidation
- Three source-backed cases passed through visible production controls at the minimum and both rounded display boundaries.
- The former rounded 10% and 70% contradictions were absent; production displayed <10.0% and >70.0% with matching classifications.
- No unexpected N/A, literal undefined value, stale control, unsupported gauge, or browser-console error was observed.
Case-level evidence is retained in validation/browser-revalidation/herder-lung-nodule-prediction-model-2026-08-03.json.
: Boundary-safe display and neutral receipts corrected and browser-revalidated locally
- A raw probability below 10% that rounds to 10.0 now displays <10.0%, and a raw probability above 70% that rounds to 70.0 now displays >70.0%; exact 10.0% and 70.0% remain Intermediate.
- PET-not-performed and recent-cancer dispositions now show a Herder-specific probability-not-assigned receipt instead of generic missing-or-invalid-input wording.
- Ten visible-browser cases passed across 11 submissions, and the unchanged source equation, full-precision Mayo handoff, and raw bands continue to pass 591/591 independent assertions.
Case-level local remediation evidence is retained in validation/browser-production/herder-lung-nodule-prediction-model.local-remediation.json; the original production finding remains retained separately.
: Production browser validation
- Ten source-backed cases were exercised on the public production route through visible browser controls; 8/10 case records passed their expected-versus-observed assertions across 11 visible submissions.
- Overall browser status: failed-ui-and-console. high: A raw Herder probability just below 10% is correctly classified Low Risk (<10%) but rounded and displayed as 10.0%, which visibly contradicts the stated threshold. | high: A raw Herder probability just above 70% is correctly classified High Risk (>70%) but rounded and displayed as 70.0%, which visibly contradicts the stated threshold. | medium: Production emitted minified React error #418 during route loads/reloads used by this run.
- Case-level inputs, expected and observed results, reset/repeat behavior, failure reproductions, and console evidence are retained in the production-browser evidence record.
Case-level production evidence is retained in validation/browser-production/herder-lung-nodule-prediction-model.json.
: Input workflow simplified and revalidated
- Reduced the public form to result-, branch-, unit-, and applicability-changing inputs; removed or consolidated non-scoring, administrative, and duplicate questions.
- Preserved the verified calculation or report-interpretation logic, thresholds, model version, component logic, and supported result pathways behind strict deterministic adapters.
- Passed the calculator-specific regression audit, adapter-parity and malformed-input checks, the 144-calculator input-quality audit, and the 43-calculator entry-burden audit.
: Full validation test
- 591/591 source-transform, threshold, end-to-end, malformed-input, Mayo-handoff, and lung-panel Herder-component checks passed with zero numerical difference.
- Mayo and Brock regressions remained green; the panel maximum-risk synthesis was not validated and remains in review.
: Correction history
- Replaced the unsupported 0.04 + 0.78 x Mayo-logit calculation and incorrect PET terms with the published Herder 2005 equation.
- Connected Herder to the verified full-precision Mayo probability fraction and removed rounded-display parsing from the lung panel.
- Added explicit solitary-solid context, PET-not-performed versus absent uptake, strict 18-100-year and 4-30-mm limits, source-cohort warnings, and later BTS uptake definitions without liver thresholds.
Verification confirms the calculator implementation against the cited model; it is not independent clinical validation, regulatory approval, or medical advice.
Related Tools
Frequently Asked Questions
When should Herder Model (Pulmonary Nodule) be used?
Use it for patients undergoing thoracic oncology risk, staging, or nodule assessment when all required inputs and the intended clinical setting are confirmed.
Can Herder Model (Pulmonary Nodule) determine treatment by itself?
No. Interpret the result with the cited evidence, complete clinical assessment, current guidelines, and patient-specific goals.
Evidence-based oncology decision support. Verify with clinical guidelines.