Pretherapy 18F-fluorodeoxyglucose-positron emission tomography (FDG-PET) produces conflicting prognostic results for patients with follicular lymphoma (FL). New research published in Blood Advances sheds light on how chemoimmunotherapies can affect FDG-PET parameters and influence interpretation of results.

 Total metabolic tumor volume (TMTV) reflects the malignant B-cell burden, while maximum standardized uptake value (SUVmax) is influenced by intratumoral T-cell uptake.

Prior studies have found differences in the prognostic effect of TMTV and SUVmax. The study authors evaluated the relationship between TMTV and SUVmax and intratumoral T cells.


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The study quantified intratumoral T-cell infiltration for 45 patients with FL and compared the infiltration with TMTV. Patients with more FL B cells within the tumor specimens had higher TMTV.

To assess SUVmax, the authors obtain SUVlesional from a subset of patients who had FDG-PET imaging before their diagnostic biopsy. Analysis found that intratumoral T cells affect the SUVmax of FL lesions. Intratumoral T-cell spatial heterogeneity may be a factor in the difference in SUV between lesions, creating inconsistency in the prognostic efficacy of SUVmax.

Chemoimmunotherapy regimens vary in how much T-cell depletion they induce. The extent of T-cell depletion can affect intratumoral T-cell update, leading to variability in the prognostic value of pretherapy FDG-PET in patients with FL.

Disclosure: Some study authors declared affiliations with biotech, pharmaceutical, and/or device companies. Please see the original reference for a full list of authors’ disclosures.

Reference

Nath K, Law SC, Sabdia MB, et al. Intratumoral T cells have a differential impact on FDG-PET parameters in follicular lymphoma. Blood Adv. 2021;5(12):2644-2649. doi:10.1182/bloodadvances.2020004051