The Deauville score is a standardized method used in medicine to interpret the results of positron emission tomography, or PET, scans. It is most frequently applied for patients with specific cancers, such as Hodgkin lymphoma and some types of non-Hodgkin lymphoma. The system provides a simple, five-point scale that helps standardize the reading of these complex images across different hospitals and clinical trials.
The Deauville Five-Point Scale
The Deauville score works by comparing the metabolic activity of a tumor, seen as a bright spot on a PET scan, to two reference areas in the body: the mediastinum and the liver. The mediastinum is the space in the chest between the lungs that contains the heart and major blood vessels, and it provides a baseline of blood-pool activity. The liver also shows a relatively consistent level of metabolic activity, making it a reliable second benchmark.
A score of 1 on the scale means there is no FDG uptake, which is the radioactive tracer used in PET scans, indicating no sign of metabolic activity in the area of the tumor. A score of 2 signifies that there is some uptake, but it is less than or equal to the activity seen in the mediastinum.
A score of 3 is assigned when the tumor’s uptake of the FDG tracer is greater than that of the mediastinum but does not exceed the activity in the liver. For a score of 4, the uptake is moderately higher than the liver’s activity. A score of 5 represents the highest level of activity, which is defined as markedly increased uptake compared to the liver or the appearance of new sites of disease that were not previously present.
Interpreting the Results
The numerical scores from the Deauville scale are grouped to determine the overall outcome of a treatment cycle. This interpretation translates the visual data from the PET scan into a clinical assessment of the cancer’s response.
Generally, a Deauville score of 1, 2, or 3 is interpreted as a “complete metabolic response.” This outcome suggests that the treatment has been successful in either eliminating the cancer cells or reducing their metabolic activity to a level that is considered inactive. Even if a residual mass is visible on a corresponding CT scan, scores of 1, 2, or 3 on the PET scan indicate that the mass is no longer metabolically active.
On the other hand, scores of 4 and 5 point toward an incomplete response or what may be termed progressive disease. A score of 4 or 5 suggests that the cancer remains metabolically active despite treatment. This finding implies that the therapeutic regimen has not been entirely effective in controlling the lymphoma. The distinction between these two groups of scores is a main factor in subsequent medical consultations and planning.
Application in Treatment Decisions
The interpretation of the Deauville score directly influences the next steps in a patient’s cancer care. For individuals who achieve a complete metabolic response—indicated by a score of 1, 2, or 3—the oncology team may decide to continue with the planned course of therapy or transition to a period of observation.
For a patient whose scan results in a score of 4 or 5, the treatment plan often requires reevaluation. An incomplete metabolic response signals that the cancer is still active, prompting the oncologist to consider several alternative actions. These may include recommending a biopsy of the active tumor area to gather more information about the remaining cancer cells.
Based on the findings, the medical team might decide to alter the treatment protocol. This could involve switching to a different combination of chemotherapy drugs or introducing another form of treatment, such as radiation therapy, to target the remaining active sites. The score itself does not dictate a single path, but rather provides the necessary information for the oncologist to make an informed decision tailored to the patient’s specific situation.