Is a Deauville Score of 5 Bad? What It Means

A Deauville score of 5 is the highest and most concerning result on the five-point scale used to interpret PET/CT scans in lymphoma. It means the scan shows metabolic activity in a suspicious area that is substantially higher than what the liver normally shows, which strongly suggests active disease. But “bad” depends heavily on context: when the scan was taken, what type of lymphoma you have, and whether a biopsy confirms that the hot spot is actually cancer and not something else like inflammation.

What the Five Points Actually Mean

The Deauville scale was developed so that doctors around the world could look at a PET/CT scan after lymphoma treatment and agree on whether the treatment is working. The scan measures how much sugar (FDG) a suspicious area absorbs compared to two internal reference points in your own body: the mediastinum (the central area of the chest) and the liver. Scores 1 through 3 generally mean things look favorable. A score of 1 means no detectable uptake above background. A score of 2 means uptake at or below the mediastinum. A score of 3 means uptake above the mediastinum but at or below the liver. These three scores are typically considered “negative,” meaning no convincing evidence of active lymphoma.

Scores 4 and 5 are where concern begins. A score of 4 means uptake moderately above the liver, and a score of 5 means uptake markedly above the liver, or new lesions have appeared. Scores of 4 and 5 are considered “positive,” suggesting the lymphoma may still be active. But as you’ll see, a score of 4 and a score of 5 carry very different weight in practice.

The Gap Between a Score of 4 and a Score of 5

One of the most important things to understand is that a Deauville 4 and a Deauville 5 are not interchangeable. Research consistently shows that outcomes for patients with a score of 5 are dramatically worse than for those with a score of 4, while patients with a 4 sometimes do nearly as well as those with lower scores.

In diffuse large B-cell lymphoma (DLBCL), one study found that using a cutoff of 5 alone to define a “positive” scan was more clinically useful than lumping 4 and 5 together. Patients who scored a 5 at interim had far worse progression-free survival compared to everyone else, while patients who scored a 4 looked more like those who scored 1 through 3.¹ A separate study of end-of-treatment scans in DLBCL confirmed this pattern: patients with a score of 4 had significantly longer progression-free and overall survival compared to those with a score of 5.²

This distinction matters because a score of 4 sits in a gray zone. Some of those patients have residual disease, but many do not. The scan may be picking up post-treatment inflammation, slow tissue healing, or other benign causes of elevated sugar uptake. A score of 5, by contrast, is a much stronger signal that active lymphoma remains.

When the Scan Happens Changes What the Score Means

Doctors use PET/CT at two key points during lymphoma treatment: partway through (interim, usually after two cycles of chemotherapy) and at the end. The same Deauville score carries different implications depending on which scan you’re talking about.

An interim scan is a progress check. A positive result at this stage doesn’t mean treatment has failed; it means the current regimen might need to be intensified. A negative interim scan is reassuring. In Hodgkin lymphoma, one study found that patients with negative interim scans had a three-year progression-free survival of about 95%, while those with positive scans dropped to around 28%.³ That’s a stark difference, and it explains why clinicians take interim results seriously.

The threshold for calling a scan “positive” can shift depending on what your doctor plans to do with the information. When dose escalation is being considered, scores of 1 through 3 count as negative and 4 through 5 as positive. But when dose de-escalation is the question, the bar tightens: only scores of 1 and 2 are considered negative, and anything from 3 upward is positive. These shifting cutoffs exist specifically to avoid over-treating or under-treating patients.⁴

An end-of-treatment scan is more definitive. If you finish your full course of chemotherapy and the PET still shows a score of 5, that’s a stronger indicator of treatment failure than the same score at the interim checkpoint. At that point, the conversation typically turns to second-line therapy or alternative treatment strategies.

What Happens After a Positive Score

Getting a Deauville 4 or 5 doesn’t automatically mean you’re switched to a completely new treatment. The response depends on your lymphoma subtype, how far along you are in treatment, and other clinical factors.

In classical Hodgkin lymphoma, for example, patients with a positive interim scan may be transitioned to a more intensive chemotherapy regimen. If a subsequent scan after the intensified therapy shows a complete response (scores 1 through 3), radiation can sometimes be omitted.⁵ Real-world data from Hodgkin lymphoma patients with interim scores of 4 or 5 shows that escalation doesn’t always improve outcomes across the board. In one cohort, advanced-stage patients who escalated treatment after a positive interim scan had better twelve-month progression-free survival than those who didn’t, but in limited-stage disease, the patients who weren’t escalated actually fared better.⁶

For primary mediastinal lymphoma patients with a score of 4 after chemotherapy, radiation therapy to the residual site has shown encouraging results. In one institutional study, the five-year overall survival was 100% and progression-free survival exceeded 90% when radiation was added after chemotherapy.⁷ That’s a reminder that a score of 4 is often very manageable with the right follow-up strategy.

A Score of 5 Doesn’t Always Mean Lymphoma

PET scans detect metabolic activity, not cancer specifically. Anything that causes cells to burn through sugar at a high rate can light up on a scan. Infection, post-treatment inflammation, granulomas, and even unrelated cancers can produce a Deauville 5. This is why biopsy confirmation often follows a high score.

A pathology study that biopsied lesions graded by Deauville score found lymphoma in all DS-5a lesions and about 74% of DS-5b lesions. But among DS-4 lesions, only 70% turned out to be lymphoma. The rest were granulomas, non-specific inflammation, unrelated malignancies, or showed no residual disease at all.⁸ A separate prospective trial in advanced Hodgkin lymphoma found that among patients with a score of 5 after six cycles of ABVD chemotherapy, 100% had confirmed Hodgkin lymphoma on biopsy. But among those with a score of 4, only about 12.5% had confirmed malignancy.⁹

The takeaway: a score of 5 has a very high rate of true disease, but even it is not infallible. And a score of 4, while technically “positive,” is wrong about active lymphoma far more often than it’s right, at least in some contexts. This is exactly why many oncologists push for biopsy before making major treatment changes based on a score alone.

Doctors Don’t Always Agree on the Score

The Deauville scale was designed to standardize how scans are read, but the process still relies on human visual judgment. In practice, readers don’t always assign the same score. A study that had multiple experts independently score the same interim PET scans in Hodgkin lymphoma found full agreement in only 56% of cases. About a third of scans had a one-level discrepancy, and 11% had a discrepancy of more than one level. The main reasons for major disagreements were differing interpretations of whether a hot lymph node was malignant or inflammatory, lesions missed by one reader entirely, and confusion caused by activated brown fat tissue, which can mimic disease.¹⁰

This imperfect agreement matters most at the borderline between 3 and 4, or between 4 and 5, where the clinical decision might change depending on which score is assigned. A study of pediatric Hodgkin lymphoma specifically found that the distinction between scores 1 through 3 versus 4 through 5 was the most reliable cutoff for clinical decision-making.¹¹ Adding quantitative measurements helped resolve about half of the minor disagreements in one study, suggesting that combining the visual score with numerical data can improve consistency.

How Scores Translate to Survival Numbers

The reason a Deauville score gets so much attention is that it predicts how likely someone is to stay in remission. The numbers vary by lymphoma subtype, but the general pattern is consistent: higher scores at the end of treatment mean worse outcomes.

In peripheral T-cell lymphoma, a study found that patients with a post-treatment Deauville score of 4 or 5 had dramatically worse five-year progression-free survival (around 5%) compared to those who scored 1 or 2 (about 70%). Those with a score of 3 fell in between. The hazard ratio for progression in the 4/5 group was roughly eight times that of the 1/2 group.¹² In extranodal NK/T-cell lymphoma, a score of 5 combined with positive Epstein-Barr virus DNA was classified as “treatment failure,” with hazard ratios for progression exceeding 18 compared to the low-risk group.¹³

These numbers are sobering, but they describe populations, not individuals. Survival statistics tell you what happened to a group of people with a similar score; they cannot predict what will happen to you specifically. Many patients with a score of 4 or even 5 go on to achieve durable remissions after additional treatment.

The Score in Newer Treatments Like CAR-T Therapy

As lymphoma treatment evolves, the Deauville score is being used to guide decisions about newer therapies too. In patients receiving CAR-T cell therapy for relapsed or refractory large B-cell lymphoma, the distinction between a score of 4 and a score of 5 on follow-up scans one month after infusion turned out to be enormous. Patients with a score of 4 at that one-month mark had a one-year progression-free survival of about 79%, comparable to those who scored 1 through 3. Patients who scored a 5, however, had a one-year progression-free survival below 9%.¹⁴ Only about a quarter of patients with a post-CAR-T score of 4 went on to progress. That finding reinforces the idea that a 4 and a 5 should not be treated as equivalent results, even in the most advanced treatment settings.

When Quantitative Measurements Add Value

The Deauville scale is a visual, qualitative tool. A radiologist compares the brightness of a suspicious area to the liver and assigns a number. Some researchers have explored whether measuring the actual SUV numbers (the quantitative metabolic uptake values) would do a better job, especially in the gray zone of scores 3 and 4 where the clinical call is hardest.

The results have been mixed. One study specifically tested whether a quantitative metric called ΔSUVmax, which measures the percentage change in metabolic activity from baseline, could outperform the Deauville scale for patients who scored 3 or 4 at the end of treatment. It could not.¹⁵ However, a separate study found that ΔSUVmax showed higher overall accuracy and predictive value for interim scans in DLBCL, with sensitivity exceeding 81% compared to the visual Deauville approach.¹⁶ In practice, many centers use the Deauville score as the primary tool and supplement with quantitative measurements when the visual read is ambiguous.

Follicular Lymphoma and Other Slower-Growing Subtypes

Most of the landmark research on the Deauville scale comes from aggressive lymphomas like Hodgkin lymphoma and DLBCL, where metabolic activity is high and PET scans are particularly useful. In slower-growing (indolent) subtypes like follicular lymphoma, the picture is somewhat different but the score still carries weight.

Research in follicular lymphoma found that patients with interim Deauville scores of 1 through 3 had lower rates of early disease progression and better progression-free survival compared to those who scored 4 or 5, regardless of whether they received traditional chemo-immunotherapy or newer chemo-free immunotherapy combinations.¹⁷ Interestingly, patients who scored 4 or 5 at the interim mark but improved to 1 through 3 by the end of induction therapy still fared worse than those who were negative at both time points. That suggests the interim scan captures something about the biology of the disease that persists even when the end-of-treatment scan looks clean.

The Anxiety Side of Scan Results

Regardless of the clinical nuance, receiving any PET/CT result triggers real anxiety. A study of cancer patients undergoing PET/CT found that average self-reported anxiety before the procedure was about 6.4 on a ten-point scale, dropping only slightly to 5.7 afterward.¹⁸ The waiting period between a scan and its interpretation is notoriously stressful, and hearing numbers like “Deauville 5” without context can be frightening.

If you’ve received a score of 4 or 5, the single most useful thing you can do is ask your oncologist where the score falls in the context of your specific treatment plan. Was this an interim scan or an end-of-treatment scan? Is biopsy warranted? Does your specific lymphoma subtype respond well to the next available line of therapy? The score is one data point in a much larger clinical picture, and doctors use it alongside pathology, lab work, and your overall health status to decide what comes next. A Deauville 5 is a serious finding, but it opens a conversation about next steps rather than closing one about options.