The Impact of Timing of Immunotherapy with Cranial Irradiation on Early Distant Brain Progression and Overall Survival in Patients with Melanoma Brain Metastases

Brain metastasis formation and irradiation by stereotactic radiation therapy combined with immunotherapy: A systematic review

INTRODUCTION

Brain metastasis (BM) is a complex process that implies immune cells and microglia. Stereotactic radiation therapy (SRT) and immunotherapy (IT) are established to increase the immune response; but their association has never been prospectively studied.

MATERIALS AND METHODS

Two reviewers performed a systematic review in original papers published up to September 2019. We analysed OS, local (mLRF) and regional (mBRF) median disease-free survival in patients with BMs after SRT with and without IT.

RESULTS

Upon 14 studies, eleven concerned melanoma, three concerned lung cancers. SRT-IT showed better OS, mLRF and mBRF than SRT. mBRF was better if SRT was performed with short delay from IT. No higher rates of radionecrosis and haemorrhage were found among groups.

CONCLUSION

This review suggests SRT combined to IT in melanoma is safe and could provide better BRF, suggesting a lymphocytic immune reaction in brain. No improvement trend was found in lung cancer BM.

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.