Evaluation of 68Ga-labeled TPP-1: A Targeted PD-L1 Probe for PET Imaging of Colorectal Cancer

Colorectal cancer is a common clinical malignancy of the digestive system. In recent years, with the improvement of living standards and changes in dietary habits, the incidence and death rate of colorectal cancer has been on the rise [1]. At present, effective treatments for colorectal cancer include surgery, chemotherapy and radiotherapy, but most lesions have already metastasized at the time point of being detected, resulting in a high death rate. The development of immunotherapeutic agents targeting PD-1/PD-L1 has affected the treatment strategy for many digestive system tumors due to their high efficacy and low toxicity compared to conventional treatments [2,3]. Unfortunately, although immuno-blocking therapy (IBT) targeting the PD-1/PD-L1 pathway has shown impressive clinical results, only a small number of patients have been benefited [4].