Predictive Value of Tumor Microenvironment PET/CT for Response and Prognosis in Aggressive Lymphoma

This multicenter study aims to evaluate the predictive value of tumor microenvironment PET/CT imaging for treatment response and prognosis in patients with aggressive lymphoma. Eligible patients with histologically confirmed aggressive lymphoma will undergo FAPI PET/CT imaging, and selected patients who are candidates for immunotherapy will undergo Grazytracer PET/CT imaging. These imaging methods are intended to assess fibroblast activation protein expression and granzyme B activity in lymphoma lesions, reflecting cancer-associated fibroblasts and cytotoxic T-cell activity in the tumor microenvironment. The study will explore optimal imaging assessment criteria and develop clinical-pathological-imaging models to predict treatment response, prognosis, and the relationship between tumor heterogeneity and refractory or relapsed disease.

Inclusion Criteria: * Histologically confirmed aggressive lymphoma. * Baseline PET/CT showing moderate to high FDG uptake in lymphoma lesions. * No previous history of malignant tumors. * No significant cardiac, hepatic, or renal dysfunction. * Expected survival of at least 6 months and ability to complete follow-up. Exclusion Criteria: * Low FDG uptake on baseline PET/CT. * Lymphoma lesions have been surgically removed, with no positive lesions available for evaluation. * Active or uncontrolled chronic inflammation or infection. * Uncontrolled diabetes mellitus. * Incomplete clinical data or loss to follow-up. * Refusal to sign the informed consent form. * Inability to lie supine for 30 minutes.