FDG PET/CT in lymphoma

A report skeleton for FDG PET/CT at staging, interim and end of treatment in FDG-avid lymphoma. It uses the Deauville five-point scale and the Lugano metabolic response categories, with technique fields from the EANM tumour imaging guideline v2.0.

Based on: Lugano classification (Cheson 2014); ICML Imaging Working Group consensus (Barrington 2014); EANM FDG PET/CT tumour imaging guideline v2.0 (Boellaard 2015)

FDG PET/CT: LYMPHOMA

CLINICAL INDICATION:
  Histology: [classical Hodgkin lymphoma / DLBCL / follicular lymphoma / other]
  Time point: [staging / interim after [ ] cycles of [regimen] / end of treatment / suspected relapse]
  Last chemotherapy [date]; radiotherapy [site, date]; G-CSF [date]; steroids [ ]

TECHNIQUE:
  Fasting [ ] h (at least 4 h); blood glucose [ ] mmol/L before injection
  18F-FDG [ ] MBq IV at [time], [site]; uptake time [ ] min (recommended 60 min, range 55–75 min)
  Coverage: [skull base / vertex] to [mid-thigh / feet]; CT: [low-dose / diagnostic contrast-enhanced]
  Height [ ] cm; weight [ ] kg; PET/CT system [ ]

COMPARISON:
  [Baseline PET/CT dated [ ] (uptake time [ ] min) / prior interim scan / none]

FINDINGS:
  Reference regions: mediastinal blood pool SUVmax [ ]; liver SUVmax [ ]
  Nodal disease above the diaphragm: [sites, size (longest and short-axis diameter), SUVmax]
  Nodal disease below the diaphragm: [ ]
  Bulk: [none / largest mass [ ] cm (longest diameter on CT)]
  Spleen: vertical length [ ] cm; [diffuse / focal uptake / normal]
  Extranodal disease: [ ]
  Bone marrow: [no FDG-avid marrow disease / focal FDG-avid marrow lesions at [ ] / diffuse uptake]
  Target lesions (up to six largest, measurable in two diameters, from different regions):
    1. [site]: [LDi x SDi] mm, SUVmax [ ], Deauville [ ]
  New lesions: [none / [ ]]
  Other findings: [ ]

DEAUVILLE FIVE-POINT SCALE (most intense residual site):
  1 = no uptake above background
  2 = uptake ≤ mediastinum
  3 = uptake > mediastinum but ≤ liver
  4 = uptake moderately > liver
  5 = uptake markedly higher than liver and/or new lesions
  X = new areas of uptake unlikely to be related to lymphoma

LUGANO METABOLIC RESPONSE (interim / end of treatment):
  CMR: score 1, 2 or 3 with or without a residual mass; no FDG-avid marrow disease; no new lesions
  PMR: score 4 or 5 with reduced uptake compared with baseline and residual mass(es) of any size; marrow uptake higher than normal marrow but reduced compared with baseline (diffuse uptake compatible with reactive change from chemotherapy allowed); no new lesions
  NMR: score 4 or 5 with no significant change in FDG uptake from baseline; marrow no change from baseline; no new lesions
  PMD: score 4 or 5 with an increase in intensity of uptake from baseline and/or new FDG-avid foci consistent with lymphoma rather than another aetiology; new or recurrent FDG-avid foci in marrow

IMPRESSION:
  1. [Staging: distribution of FDG-avid disease; stage per Lugano [I / II / II bulky / III / IV]]
  2. Deauville score [ ] at [site]; Lugano response: [CMR / PMR / NMR / PMD]
  3. [Comparison with baseline and recommendation, e.g. biopsy of a new discordant lesion]

Before you sign

• Score the most intense residual site against both reference regions, and record both SUVmax values. The imaging consensus suggests score 4 for uptake above the liver SUVmax and score 5 for uptake 2–3 times the liver SUVmax.
• A score of 3 usually means a good prognosis with standard treatment, particularly at interim. In de-escalation trials it may count as an inadequate response, so check the protocol.
• In Hodgkin lymphoma staged with PET/CT, bone marrow biopsy is no longer needed. In DLBCL, PET evidence of marrow involvement is usually enough; biopsy is indicated after a negative scan only if discordant histology matters for a trial or for management.
• Bulk in Hodgkin lymphoma is a single nodal mass of 10 cm or more, or more than a third of the transthoracic diameter at any thoracic vertebral level on CT. For NHL, 6 cm (follicular) and 6–10 cm (DLBCL) have been suggested but not validated, so record the longest diameter.
• Splenomegaly is a vertical length over 13 cm.
• Where physiological uptake is high (Waldeyer ring, extranodal sites), CMR may be inferred if uptake at initial sites is no higher than surrounding normal tissue.
• In response assessment, Lugano allows diffuse marrow uptake compatible with reactive change from chemotherapy. If focal marrow changes persist despite a nodal response, consider MRI, biopsy or an interval scan. Record G-CSF and radiotherapy dates.

Sources

1. Cheson BD, Fisher RI, Barrington SF, et al. Recommendations for initial evaluation, staging, and response assessment of Hodgkin and non-Hodgkin lymphoma: the Lugano classification. J Clin Oncol. 2014;32:3059–68.
2. Barrington SF, Mikhaeel NG, Kostakoglu L, et al. Role of imaging in the staging and response assessment of lymphoma: consensus of the International Conference on Malignant Lymphomas Imaging Working Group. J Clin Oncol. 2014;32:3048–58.
3. Boellaard R, Delgado-Bolton R, Oyen WJG, et al. FDG PET/CT: EANM procedure guidelines for tumour imaging: version 2.0. Eur J Nucl Med Mol Imaging. 2015;42:328–54.