The fact that ionizing radiation can be not only an immunosuppressive has been known for a long time. However, until the advent of immunotherapy with checkpoint inhibitors, there has been increased interest in the possibility of using immunotherapy and radiotherapy in combination.
Although this combination is accepted already as beneficial, there are still many issues that are yet to be solved, such asi the timing of both modalities, the definition of optimal doses and regimen. This review tries to summarize the essential information we have about this combination, which can also serve as a clue in planning the treatment strategy.