Deauville Score - 1, 2, 3, 4, 5 in Lymphoma PET

Deauville Score

1. What is Deauville Score?

2. Deauville Score 1

3. Deauville Score 2

4. Deauville Score 3

5. Deauville Score 4

6. Deauville Score 5

7. Deauville Score in Lymphoma PET

What is Deauville Score?

The Deauville Score is a five-point visual scoring system used by doctors to interpret FDG PET/CT scans in patients with lymphoma. In simple words, it helps compare how much glucose-like tracer activity is seen in lymphoma areas compared with normal reference areas of the body, mainly the mediastinum and liver. Because lymphoma cells often use more glucose than normal tissues, they can appear as “hot” or active areas on PET imaging. The Deauville system gives this activity a number from 1 to 5, making the PET result easier to understand for treatment response, follow-up, and clinical decision-making. It is commonly used in both Hodgkin lymphoma and many types of non-Hodgkin lymphoma.

The main purpose of the Deauville Score in lymphoma PET is not just to say whether a scan looks bright or dark. It helps doctors decide whether the disease is responding well, partially responding, unchanged, or possibly progressing. A lower score usually suggests a better metabolic response, while a higher score may suggest persistent active disease, although the final meaning depends on timing, treatment stage, lymphoma type, symptoms, and the full radiology report. Important points include:

• Scores 1–3 are often considered favorable in many treatment-response settings.
• Scores 4–5 may indicate residual or active lymphoma activity.
• The score should always be interpreted by an oncology team, not by the number alone.

Deauville Score 1

Deauville Score 1 means there is no abnormal FDG uptake in the area being assessed. This is generally the most reassuring result on the five-point scale. In lymphoma PET interpretation, Score 1 suggests that previously active lymphoma sites no longer show visible metabolic activity above background. For many patients, this may be described as an excellent metabolic response, especially when the scan is performed after treatment. However, doctors still review the full scan, CT findings, blood tests, symptoms, and previous imaging before making a final conclusion. A Score 1 does not mean the patient should stop follow-up, but it is usually a very positive imaging sign.

In blog-style language, Deauville Score 1 can be understood as the “cleanest” PET response category. It means the scan does not show suspicious active uptake at the lymphoma site. Sometimes a residual mass may still be visible on CT, but if it has no FDG activity, it may represent scar tissue or treated disease rather than active lymphoma. This distinction is one reason PET/CT is so useful in lymphoma care. Key features of Deauville Score 1 include:

• No visible abnormal uptake in the target lesion.
• Usually linked with complete metabolic response.
• Often a favorable sign after chemotherapy, immunotherapy, or radiation.

Deauville Score 2

Deauville Score 2 means the FDG uptake in the lymphoma area is equal to or less than the mediastinum, which is the central area of the chest between the lungs. This score is also generally considered a good response in many lymphoma PET reports. It means that even if slight uptake is present, it is very low and not stronger than the normal reference activity in the mediastinum. In many clinical settings, Deauville Score 2 is grouped with Score 1 as a negative or favorable PET result, especially at the end of treatment. Still, the final interpretation depends on the patient’s full clinical situation.

For patients reading their report, Deauville Score 2 may sound worrying because it still mentions “uptake.” However, not all uptake means cancer. PET scans can show mild activity from normal tissues, inflammation, healing, infection, or treatment effects. The Deauville system helps separate low-level activity from more concerning uptake by comparing it with standard reference areas. In lymphoma PET, Score 2 usually suggests that the uptake is low enough to be considered non-aggressive or compatible with good treatment response. Important points are:

• Score 2 is usually a favorable PET category.
• Uptake is not greater than mediastinal blood pool activity.
• It is commonly interpreted as complete metabolic response in many protocols.

Deauville Score 3

Deauville Score 3 means the FDG uptake is greater than the mediastinum but less than or equal to the liver. This is an important middle category in the Deauville five-point scale. In many lymphoma treatment-response settings, Score 3 can still be considered a good response, especially when assessed at the end of therapy. However, its meaning may vary depending on the type of lymphoma, the treatment stage, and whether the scan is interim or end-of-treatment. Some oncologists treat Score 3 as negative in certain cases, while in other high-risk settings they may interpret it more cautiously.

Deauville Score 3 is often the score that patients find most confusing because it is not as clearly “no uptake” as Score 1, but it is also not as concerning as Scores 4 or 5. The key comparison is the liver. If the uptake remains no higher than the liver, it is often considered controlled or acceptable in many clinical contexts. Doctors may also compare the current PET scan with older scans to see whether the uptake has decreased significantly. Useful points include:

• Score 3 means uptake is above mediastinum but not above liver.
• It may still represent complete metabolic response in many lymphoma protocols.
• Clinical context is very important for final interpretation.

Deauville Score 4

Deauville Score 4 means the FDG uptake is moderately higher than the liver. This score is more concerning than Scores 1, 2, and 3 because uptake above liver activity may suggest residual active lymphoma. However, Score 4 does not automatically mean treatment failure. It may represent partial response if the uptake has clearly reduced compared with the previous scan. It may also be affected by inflammation, infection, recent therapy, or healing tissues. Because of this, doctors do not usually make decisions from the number alone. They review the pattern of uptake, lesion size, symptoms, blood markers, biopsy results if needed, and treatment timeline.

In lymphoma PET reporting, Deauville Score 4 often leads to closer evaluation. If a patient had very high uptake before treatment and now has only moderately increased uptake, the report may describe partial metabolic response. If the uptake is unchanged or increasing, the concern may be higher. This is why comparison with baseline PET is extremely important. Common next steps may include observation, repeat imaging, biopsy, treatment adjustment, or multidisciplinary discussion. Key points about Score 4 include:

• Score 4 shows uptake moderately above the liver.
• It can suggest residual active disease, but false positives are possible.
• Trend over time matters as much as the score itself.

Deauville Score 5

Deauville Score 5 means FDG uptake is markedly higher than the liver and/or there are new lesions suspicious for lymphoma. This is generally the most concerning category on the Deauville scale. In many cases, Score 5 may indicate active lymphoma, poor metabolic response, progression, or relapse, depending on when the scan was done. For example, a Score 5 after treatment may raise concern that lymphoma is still active. A Score 5 with new lesions may suggest progressive disease. However, even this score must be interpreted carefully because PET uptake can sometimes occur from infections, inflammatory conditions, recent procedures, or other non-cancer causes.

Patients often search for Deauville Score 5 meaning because it appears alarming in reports. The practical meaning is that the PET scan shows strong metabolic activity that needs medical attention and explanation. It does not always mean that there is no treatment option. Many lymphoma patients with high PET scores may still receive further therapy, biopsy confirmation, targeted treatment, immunotherapy, radiation, stem cell transplant evaluation, or clinical-trial options depending on the disease type. Important points are:

• Score 5 means markedly increased uptake compared with liver and/or new lesions.
• It is usually considered PET-positive in lymphoma response assessment.
• A biopsy may sometimes be needed before changing treatment.

Deauville Score in Lymphoma PET

The Deauville Score in lymphoma PET is mainly used to assess metabolic response to treatment. PET/CT uses FDG, a glucose-like tracer, because many lymphoma cells are metabolically active and absorb more FDG than normal tissue. The Deauville system then compares this uptake visually with the mediastinum and liver. This makes the report more standardized and easier for oncologists, radiologists, and nuclear medicine physicians to discuss. It is especially useful because lymphoma masses can remain visible on CT even after cancer activity has disappeared. PET helps determine whether a remaining mass is metabolically active or likely inactive scar tissue.

In practical lymphoma care, the Deauville score may be used after a few cycles of treatment, at the end of treatment, or during follow-up if relapse is suspected. The same number can have different meaning depending on timing. For example, a Score 4 during interim treatment may show improvement if it was previously Score 5 with much higher uptake. But a new Score 5 after complete response may be more concerning. Patients should ask their doctor how the score fits into their exact lymphoma subtype and treatment plan. Important questions include:

• Was this PET scan done before, during, or after treatment?
• Has the uptake decreased compared with the previous scan?
• Are there new lesions or only residual mild uptake?
• Does the oncology team recommend repeat PET, biopsy, or treatment change?