Exceptionally low metabolic activity in aggressive peripheral T-cell lymphoma

Area of Science:

• Oncology
• Nuclear Medicine
• Hematology

Background:

• Non-Hodgkin's lymphoma (NHL) encompasses diverse subtypes with varying aggressiveness.
• Follicular lymphoma (FL) grades (1-3) represent a spectrum from indolent to aggressive B-cell lymphomas.
• Peripheral T-cell lymphoma (PTC) is an aggressive non-Hodgkin's lymphoma subtype.

Purpose of the Study:

• To compare the metabolic activity of peripheral T-cell lymphoma (PTC) with other aggressive T-cell lymphomas (OTC) and follicular lymphoma (FL) grades.
• To assess the utility of 2-deoxy-2-[¹⁸F]fluoro-d-glucose positron emission tomography-computed tomography (FDG-PET/CT) in differentiating aggressive T-cell lymphomas based on metabolic behavior.

Main Methods:

• Analysis of pretreatment FDG-PET/CT scans from 33 patients diagnosed with aggressive T-cell NHL and FL.
• Measurement of maximal standardized uptake value (SUV) in the biopsy region (BxSUV) and the highest tumor activity in the body (BmSUV).
• Comparison of metabolic parameters across five groups: FL grades 1, 2, and 3; PTC; and OTC.

Main Results:

• Significant differences in BxSUV and BmSUV were observed among the five groups (P = 0.036 and P = 0.026, respectively).
• PTC demonstrated significantly lower metabolic activity compared to OTC and high-grade FL (FC3).
• PTC's BmSUV was comparable to low-grade FL (FC1, FC2) but lower than FC3 and OTC.

Conclusions:

• Peripheral T-cell lymphoma (PTC) exhibits exceptionally low metabolic activity on FDG-PET/CT.
• The metabolic profile of PTC is similar to indolent B-cell lymphomas (FL grades 1 and 2), not aggressive lymphomas.
• FDG-PET/CT findings suggest that PTC's biological behavior may differ from other aggressive T-cell lymphomas.