This research aimed to synthesize lutetium-177- and actinium-225-labeled PD-L1 inhibitory peptides (177Lu-DOTA-PD-L1-i and 225Ac-HEHA-PD-L1-i) and to preclinically evaluate their potential as radiopharmaceuticals for targeted radiotherapy of various cancers at the tumor microenvironment level. Here, CD274 is linked to neoplasm.