Cognitive Impairment in Patients With Diffuse Large B-Cell Lymphoma

This is a prospective, non-randomized interventional diagnostic study conducted at the Institute of Oncology Ljubljana. The study does not assign or modify therapeutic regimens; chemotherapy is administered exclusively according to clinical indication. The research intervention consists of a structured neurocognitive assessment protocol and biomarker analyses performed at predefined time points during treatment and follow-up. Adult patients with newly diagnosed diffuse large B-cell lymphoma (DLBCL) will be enrolled into parallel groups based on clinically indicated treatment (systemic chemotherapy alone or systemic plus intrathecal chemotherapy). A comparison group of healthy relatives will also be included. Cognitive function will be assessed at baseline (prior to treatment initiation), after the first chemotherapy cycle, and 12 months after treatment initiation. In patients receiving intrathecal chemotherapy, an additional cognitive assessment will be performed before the last intrathecal cycle. Cerebrospinal fluid (CSF) biomarkers (phosphorylated tau, total tau, amyloid beta 40, amyloid beta 42, neurofilament light chain, GFAP) will be quantified in patients receiving intrathecal chemotherapy. CSF samples will be collected during clinically indicated lumbar punctures performed for therapeutic purposes. No additional lumbar punctures will be performed solely for research purposes. The primary objective is to evaluate longitudinal changes in cognitive performance and to identify clinical and biological predictors of treatment-associated cognitive impairment.