Lymphoma Staging & Response: Lugano / Deauville
The FDG-PET staging and 5-point response framework for lymphoma
Quick Answer
The Lugano classification is the FDG-PET/CT-based system for staging and response assessment of FDG-avid lymphoma. Anatomic extent is described in stages I–IV (an Ann-Arbor-derived scheme); metabolic response is scored with the Deauville 5-point scale (5-PS), comparing lesion uptake to mediastinal blood pool and liver. Scores 1–3 are generally a complete metabolic response (context-dependent), 4–5 residual disease. The same reference regions must be used across serial scans.
Why Standardize
Lymphoma management is increasingly response-adapted — interim PET can escalate or de-escalate therapy — so a reproducible, reference-anchored score is essential. Lugano/Deauville replaced ad-hoc "positive/negative" reads and older CT-only criteria, aligning staging and response on FDG-PET for avid histologies.
Lugano Staging
| Stage | Extent |
|---|---|
| I | One node/nodal region or one extranodal site (IE) |
| II | ≥ 2 nodal regions same side of the diaphragm (± limited contiguous extranodal, IIE) |
| III | Nodal regions both sides of the diaphragm, or nodal + splenic |
| IV | Diffuse/disseminated extranodal involvement (± nodal) |
Modifiers: A/B (absence/presence of B symptoms — mainly for Hodgkin), and descriptors for bulk. In FDG-avid lymphoma, PET assesses bone-marrow involvement (focal/diffuse vs liver), often obviating a staging marrow biopsy.
Deauville 5-Point Scale
| Score | Uptake relative to reference |
|---|---|
| 1 | No uptake above background |
| 2 | ≤ mediastinal blood pool |
| 3 | > mediastinum but ≤ liver |
| 4 | Moderately > liver |
| 5 | Markedly > liver and/or new lesions |
| X | New uptake unlikely related to lymphoma |
Reference regions are fixed: mediastinal blood pool and liver. Report the score, not just "positive/negative."
Interpreting the Score (Context Matters)
- End-of-treatment: 1–3 = complete metabolic response (CMR); 4–5 = residual disease (partial response, no response, or progression by trend).
- Interim (response-adapted trials): some protocols count only 1–2 (or 1–3) as "negative" for de-escalation — the exact cut is protocol-specific. Score 4–5 with declining uptake may still represent response at interim.
- Score 3 is deliberately "in-between": often adequate response at end-of-treatment, but treated cautiously in de-escalation settings.
Response Categories (Lugano)
- Complete metabolic response (CMR): Deauville 1–3 (residual mass allowed).
- Partial metabolic response (PMR): reduced uptake, Deauville 4–5 with decreased uptake vs baseline, no new lesions.
- No metabolic response (NMR): unchanged uptake.
- Progressive metabolic disease (PMD): increased uptake and/or new FDG-avid lesions.
Interim PET & Response-Adaptation
Interim PET (typically after ~2 cycles) is prognostic and underpins response-adapted therapy — de-escalating (e.g. omitting bleomycin in Hodgkin per RATHL) when negative and escalating when positive. The score guides, it does not dictate; thresholds and actions are protocol-specific.
Common Pitfalls
- Reporting a residual mass as "positive" without a Deauville score — a residual mass at ≤ liver (1–3) is a CMR.
- Using inconsistent reference regions across serial scans (blood pool/liver must stay fixed).
- Thymic rebound, G-CSF-stimulated marrow, brown fat, and inflammation causing false positives after therapy.
- Applying an end-of-treatment cut-off to an interim de-escalation decision (different thresholds).
- Assuming FDG-negativity excludes low-avidity histologies (some indolent lymphomas).
Board Pearls
Report lymphoma response with a Deauville score against mediastinal blood pool and liver: 1–3 generally complete metabolic response (context-dependent), 4–5 residual disease — and use the same reference regions on every serial scan.
Interim PET (~2 cycles) is prognostic and underpins response-adapted therapy (RATHL), but the negative threshold (1–2 vs 1–3) is protocol-specific — the score guides, it does not dictate.
A residual anatomic mass with uptake ≤ liver is a complete metabolic response, not "positive." Beware the post-therapy false positives — thymic rebound, G-CSF marrow, brown fat, inflammation — and remember low-avidity histologies (MALT, small lymphocytic, low-grade follicular) can be PET-negative despite disease.
Related Pages
- Disease: Lymphoma (histology-specific FDG avidity, transformation).
- Tool: Deauville score calculator.
- Tracer: FDG; pitfalls: Pearls, pitfalls & normal variants.
Figure / Diagram Suggestions
- A Deauville 1–5 visual scale (uptake vs blood pool vs liver).
- Lugano stages I–IV schematic (diaphragm-based nodal/extranodal extent).
- An interim response-adaptation flow (negative → de-escalate; positive → escalate).
Self-Check (Board-Style)
Q1. At end of treatment, a residual mediastinal mass shows uptake equal to liver. Deauville score and response category?
Answer: Deauville 3 (≤ liver) → generally a complete metabolic response at end-of-treatment, despite the residual anatomic mass.
Q2. Which two reference regions anchor the Deauville scale, and why keep them fixed?
Answer: Mediastinal blood pool and liver — keeping them fixed across serial scans makes the score reproducible and comparable over time.
Q3. Why might a Deauville threshold differ between an interim de-escalation decision and end-of-treatment assessment?
Answer: Interim de-escalation protocols may require a stricter "negative" (e.g. 1–2) to safely reduce therapy, whereas end-of-treatment CMR generally accepts 1–3 — thresholds are protocol-specific.
Q4. A new focus of diffuse marrow and anterior mediastinal uptake appears after chemotherapy with G-CSF. Progression?
Answer: Likely benign — G-CSF-stimulated marrow and thymic rebound are classic post-treatment false positives; correlate with timing before scoring as progression.
Evidence & sources
https://nuc.med/lymphoma-staging-lugano-deauville/ Report an issue