FDG PET/CT in oncology

A report skeleton for FDG PET/CT staging, restaging and response assessment in solid tumours. It records the acquisition and quantification items the EANM tumour guideline v2.0 asks for, and gives the PERCIST 1.0 and EORTC response fields in full.

Based on: EANM FDG PET/CT tumour imaging guideline v2.0 (Boellaard 2015); PERCIST 1.0 (Wahl 2009); EORTC PET response criteria (Young 1999)

FDG PET/CT

CLINICAL INDICATION:
  Tumour: [site, histology]; question: [staging / restaging / response assessment / suspected recurrence / unknown primary]
  Treatment: [chemotherapy (last cycle [date]) / immunotherapy / radiotherapy (site, date) / surgery (date) / G-CSF (date)]

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)
  Height [ ] cm; weight [ ] kg; sex [ ]
  PET/CT system [ ]; EARL-compliant reconstruction for quantification: [yes / no]
  Coverage: [skull base / vertex] to [mid-thigh / feet]; CT: [low-dose / diagnostic, IV contrast yes / no]
  SUV normalisation: [body weight (SUV) / lean body mass (SUL)]; glucose-corrected: [no / yes]
  Special processing: [respiratory gating / motion correction / none]

COMPARISON:
  [Prior PET/CT dated [ ], uptake time [ ] min, same system: yes / no / none]

FINDINGS:
  Reference: liver SUL mean [ ] (SD [ ]) in a 3 cm spherical region in the right lobe
  Primary tumour: [site, size], SUVmax [ ], SULpeak [ ]
  Regional nodes: [ ]
  Distant disease: [ ]
  Target lesion(s) for response: [hottest lesion site]: SULpeak baseline [ ], now [ ], change [ ]%
  Incidental findings: [ ]
  Physiological uptake and pitfalls considered: [brown fat / muscle / inflammation / post-treatment change]

PERCIST 1.0 (if applicable):
  Measurable disease: SULpeak ≥ 1.5 × liver SUL mean + 2 SD
  CMR: complete resolution of FDG uptake in the measurable target lesion, below mean liver activity and indistinguishable from surrounding blood pool; all other lesions at blood-pool level; no new FDG-avid lesions
  PMR: reduction of at least 30% in target lesion SULpeak, with an absolute drop of at least 0.8 SUL units; no new lesions
  SMD: not CMR, PMR or PMD
  PMD: > 30% increase in SULpeak with > 0.8 SUL unit increase; OR visible increase in extent of FDG uptake (75% in TLG volume with no decline in SUL); OR new FDG-avid lesions typical of cancer
  Category: [CMR / PMR / SMD / PMD]

EORTC 1999 (if applicable):
  CMR: complete resolution of FDG uptake within the tumour volume, indistinguishable from surrounding normal tissue
  PMR: reduction of 15–25% in tumour SUV after one cycle and > 25% after more than one cycle
  SMD: increase in SUV < 25% or decrease < 15%, with no visible increase in extent (20% in longest dimension)
  PMD: increase in SUV > 25% within the tumour region defined on the baseline scan; visible increase in extent (20% in longest dimension); or new FDG uptake in metastatic lesions
  Category: [CMR / PMR / SMD / PMD]

IMPRESSION:
  1. [Stage-relevant findings / answer to the question]
  2. [Response category and criteria used, with comparison scan date]
  3. [Recommendation]

Before you sign

• Report glucose, injected activity, uptake time, height, weight and the PET/CT system. Without these, SUVs cannot be compared between studies. EANM proceeds with a clinical scan if glucose is below 11 mmol/L; above that, it should be rescheduled or the patient excluded.
• Keep follow-up scans on the same system with the same uptake interval, within 10 min of the baseline. PERCIST asks for within 15 min, always 50 min or later, and for liver SUL within 20% (and under 0.3 units) of baseline.
• Insulin should not be given to lower glucose unless more than 4 h separate the insulin from the FDG injection.
• By default PERCIST 1.0 assesses the SULpeak of the single hottest lesion. Measuring up to five lesions (two per organ) is an optional approach.
• State which criteria you applied, PERCIST or EORTC. Their thresholds differ, and EORTC uses SUV in a baseline-defined region, not SULpeak.
• SULpeak is measured in a 1.2 cm diameter (about 1 mL) sphere. The measurable-disease threshold is 1.5 × liver SUL mean + 2 SD. The alternative reference is blood pool: 2.0 × SUL mean in a 1 cm region of the descending thoracic aorta.
• Name the reconstruction only if it is non-standard, for example motion correction. Quantitative comparison needs EARL-compliant or otherwise harmonised settings.

Sources

1. 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.
2. Wahl RL, Jacene H, Kasamon Y, Lodge MA. From RECIST to PERCIST: evolving considerations for PET response criteria in solid tumors. J Nucl Med. 2009;50 Suppl 1:122S–50S.
3. Young H, Baum R, Cremerius U, et al. Measurement of clinical and subclinical tumour response using [¹⁸F]-fluorodeoxyglucose and positron emission tomography: review and 1999 EORTC recommendations. Eur J Cancer. 1999;35:1773–82.