Advances in Functional and Metabolic Imaging for Early Tumor Treatment Response and Resistance Evaluation: A Review

Early assessment of tumor treatment response and elucidation of resistance mechanisms are critical for optimizing therapeutic strategies and improving patient outcomes. Functional and metabolic imaging technologies, particularly positron emission tomography (PET) combined with specific tracers, enable dynamic monitoring of tumor cell metabolism and microenvironmental changes during the initial phases of therapy. This capability facilitates early prediction of treatment efficacy and investigation into mechanisms underlying drug resistance. This review synthesizes recent advances in the application of functional and metabolic imaging for early tumor treatment response evaluation and resistance assessment. Emphasis is placed on integrating multimodal imaging techniques with molecular biology approaches to comprehensively analyze the relationships among imaging biomarkers, tumor heterogeneity, immune microenvironment, and molecular pathways. The article further explores the clinical translational potential of these imaging modalities while addressing current challenges and limitations. By providing an updated overview of this rapidly evolving field, this review aims to guide future research and clinical application toward more precise and personalized oncology care.