Skip to content
R
Visit FlowRad

Herder Model (Mayo + FDG-PET) for SPN Malignancy Risk

Herder 2005 (Chest) / BTS 2015

Estimates the probability that an indeterminate solid pulmonary nodule is malignant by combining the six Mayo Clinic predictors (age, smoking, remote cancer history, diameter, spiculation, upper-lobe location) with the qualitative FDG-PET uptake grade. This is the model the BTS 2015 guideline uses to re-assess risk after PET-CT.

Also searched as: solitary pulmonary nodule · BTS · lung nodule · pulmonary nodule

Patient age
years
Current or former smoker
Extrathoracic cancer >5 years ago

History of an extrathoracic malignancy diagnosed more than 5 years before nodule detection.

Nodule largest diameter

Model derived on nodules <30 mm; BTS applies it from 8 mm upward.

mm
Spiculated margin
Located in an upper lobe
FDG uptake grade (BTS ordinal scale)

Qualitative four-point scale recommended by BTS for PET-CT reporting.

Information
Incomplete input
  • Please provide: patient age (years), current or former smoking (yes/no), extrathoracic cancer >5 years ago (yes/no), nodule diameter (mm), spiculation (yes/no), upper-lobe location (yes/no), FDG-PET uptake grade (absent / faint / moderate / intense).

How this tool works

The Herder model (Herder 2005, Chest) was derived in 106 patients with indeterminate solitary pulmonary nodules referred for FDG-PET. It first computes the Mayo (Swensen) probability from three clinical and three radiographic predictors, then re-fits a logistic equation combining that probability with the four-level visual FDG uptake grade (absent, faint, moderate, intense); adding PET improved discrimination from AUC 0.79 to 0.92. The BTS 2015 guideline recommends PET-CT for nodules whose initial Brock risk exceeds 10%, reporting uptake on the ordinal scale (absent = background lung, faint = up to mediastinal blood pool, moderate = above blood pool, intense = markedly above blood pool), and re-assessing with this model: below 10% supports CT surveillance, 10–70% supports consideration of image-guided biopsy, and above 70% favours surgical resection. Coefficients are transcribed from the primary report and verified against the official BTS online calculator, whose outputs this implementation reproduces exactly.

References

Implemented from the cited published sources. Educational use only; confirm against current guidelines before clinical use.

Clinical questions that use this

Vetting guides that reach for this tool.

Related calculators

Same subspecialty, overlapping subject matter.

Brock (PanCan) Pulmonary Nodule Malignancy RiskNodule Volume Doubling Time (VDT)BTS 2015 Pulmonary Nodule Guideline Navigator