Optimal Timing and Sequence of Immunotherapy When Combined with Stereotactic Radiosurgery in the Treatment of Brain Metastases.

Checkpoint immunotherapy (CIT) is an emerging and exciting treatment modality for the treatment of cancer. Much excitement has ensued in the potential of CIT to revolutionize the treatment and prognosis of brain metastases. The combination of stereotactic radiosurgery (SRS) and CIT has also been studied and showed promise compared with either treatment modality alone. However, several questions have arisen, in particular, the timing at which SRS and CIT should be administered relative to each other. We reviewed the reported data and attempted to offer a potential answer to this question.