PROBLEM TO BE SOLVED: To provide a method for solving the problems of local recurrence and metastasis in the treatment of cancer. SOLUTION: a. Administering at least one dose of radiation therapy; b. Administering at least one PD-1 and/or PD-L1 antagonist, wherein the at least one PD-1 and/or PD-L1 antagonist is administered on the same day or up to 4 days after administration of radiation therapy. Method of administration. It is preferred that said at least one PD-1 and/or PD-L1 antagonist is at least one PD-1 and/or PD-L1 antibody or functional part thereof. [Selection diagram] Figure 1【課題】がんの治療において、局所性再発と転移の問題を解決する方法の提供。【解決手段】a.少なくとも1用量の放射線療法を投与するステップと;b.少なくとも1つのPD-1及び/又はPD-L1拮抗薬を投与するステップとを含み、少なくとも1つのPD-1及び/又はPD-L1拮抗薬が、放射線療法の投与と同日に又は4日後までに投与される方法。前記少なくとも1つのPD-1及び/又はPD-L1拮抗薬が、少なくとも1つのPD-1及び/もしくはPD-L1抗体又はその機能性部分であることが好ましい。【選択図】図1