Pre-Treatment 18F-FDG PET/CT reveals altered brain metabolic network connectivity in patients with diffuse large B-cell lymphoma: Implications for cancer-related cognitive impairment.

Background: Cancer-related cognitive impairment (CRCI) is prevalent among patients with diffuse large B-cell lymphoma (DLBCL), often manifesting prior to treatment and frequently remaining unrecognized.

Purpose: This study aims to assess CRCI in DLBCL patients before treatment by utilizing 18F-FDG PET/CT metabolic networks to facilitate early detection and intervention.

Methods: We conducted a cross-sectional study involving 77 participants from our hospital's PET-CT center, which included 15 healthy controls and 62 DLBCL patients (29 in stages I + II and 33 in stages III + IV). Using the automated anatomical atlas 3 (AAL3) template, we segmented the 18F-FDG PET brain images into 90 regions, extracted the standard uptake value (SUV) for each region, and calculated its ratio (SUVr) using the cerebellum as a reference. We analyzed connectivity within the brain's metabolic network across the three groups.

Results: DLBCL patients exhibited significantly lower mean degree, closeness centrality, degree of participation in connected components (DPCC), average clustering coefficient (ACC), and clustering coefficient compared to controls (P < 0.001). Patients in stages III + IV demonstrated even lower values. The average shortest path length (ASPL) was significantly higher in DLBCL patients, with stage III + IV patients showing an ASPL nearly three times that of controls and twice that of stage I + II patients. Significant differences in mean degree, closeness centrality, and clustering coefficient were observed among the groups (P < 0.001).

Conclusions: CRCI is apparent in DLBCL patients at early stages and deteriorates with disease progression. It is crucial to integrate early detection and cognitive assessments into clinical practice for DLBCL patients.