Immune checkpoint blockade (ICB) therapy has become a milestone breakthrough in oncology by activating the host immune system to recognize and eliminate tumor cells . Among these, programmed death protein 1 (PD-1) and its ligand (PD-L1) are currently the most widely used targets in clinical practice . However, clinical data indicate that only a subset of patients benefit from anti-PD-1/PD-L1 therapy. Due to the heterogeneity of the tumor microenvironment and the spatiotemporal dynamic changes in PD-L1 expression, traditional tissue biopsy-based detection methods often fail to comprehensively assess disease status, leading to limited treatment response rates . Therefore, there is an urgent need to develop precise strategies for non-invasive, real-time, and dynamic evaluation of PD-L1 expression and treatment response.
Nuclear medicine molecular imaging techniques, particularly positron emission tomography (PET), provide a critical means for non-invasive in vivo visualization of tumor biomarkers . Given the pivotal role of PD-L1 in tumor immune evasion, real-time monitoring of its expression levels is of significant importance for the precise guidance of immunotherapy. In recent years, radiotracer agents based on peptides and small molecules have garnered considerable attention due to their advantages in tissue penetration, rapid blood clearance, and high signal-to-noise ratio imaging. Various PD-L1 probes (e.g., \[¹⁸F\]BMS-986229, \[¹⁸F\]AlF-NOTA-IMB) have demonstrated promising application potential in preclinical or clinical studies . Meanwhile, although PD-1/PD-L1 monoclonal antibodies such as nivolumab and atezolizumab have significantly improved treatment outcomes for multiple tumors , they still exhibit inherent limitations in tissue penetration, in vivo clearance rate, imaging background, immunogenicity, and cost. Additionally, PD-L1-targeted therapies alone show limited efficacy in some patients, prompting researchers to further explore novel mechanisms such as protein degradation targeting (PROTAC) to achieve more comprehensive regulation of PD-L1.
Age over 18 years, gender not restricted;
patients with malignant tumors confirmed by biopsy or surgical pathology;
Imaging findings of suspicious lymph nodes or distant metastases;
informed consent signed in writing by the subject or his/her legal guardian.
patients who have received antitumor therapy prior to PET/CT or PET/MR scanning;
Patients with severe medical conditions who cannot tolerate PET/CT or PET/MR scans;
The alternative subjects have contraindications to PET/CT or PET/MR scans;
exposure to radiation of more than 50 mSv in the past year;