Imaging studies—such as PET/CT and CT scans—have become the standards that provide a baseline against which treatment response can be more accurately assessed.1 Imaging is essential for determining disease stage.1,2
Chest/abdominal/pelvic (C/A/P) CT with contrast of diagnostic quality and/or whole-body PET/CT scan are required for diagnosis of FL. PET/CT scan is essential if radiation therapy is planned for stage I or II disease.2
PET-CT scan
Imaging studies are ordered at initial diagnosis, staging, and when evaluating treatment response, and they are critical to optimal management of patients with NHL.1 PET improves accuracy of staging and PET-CT provides a baseline against which response can be more accurately assessed.1
- Contrast-enhanced CT is preferred for radiation treatment planning and for distinguishing bowel from lymphadenopathy1
- PET/CT is the standard for routine staging of FDG*-avid, nodal lymphomas (lymphomas whose 'hot' nodes or tumors take up the FGD), whereas CT is indicated for nonavid histologies1
- Note: FL is FDG-avid in more than 95% of all cases3
The Deauville Criteria
The Deauville criteria is a five-point scale (5-PS) to score PET-CT images based on the location and intensity of FDG uptake. The 5-PS scale is validated for evaluation during treatment (interim) and for remission assessment at the end of treatment. The 5-PS scores the most intense uptake in a site of initial disease, if present, as follows4:
- No uptake
- Uptake in lesion ≤ mediastinum
- Uptake in lesion > mediastinum but ≤ liver
- Uptake in lesion moderately higher than liver
- Uptake in lesion markedly higher than liver and/or new lesions
- New areas of uptake unlikely to be related to lymphoma
*FDG (fluorodeoxyglucose) is a dye that is picked up by the PET scan.
CT, computerized tomography; FDG-PET, fluorodeoxyglucose (FDG)-positron emission tomography (PET); PET/CT, positron emission tomography-computed tomography.