Fig. 1.

Flow chart depicting the study inclusion algorithm. This figure gives an overview of our study patient selection. At our institution, 483 patients with BM from melanoma, breast cancer, GI or GU cancer were treated with GKRS for at least one BM between June 2012 (implementation of the new Gamma Knife® Perfexion™ at our institution) and December 2019. After excluding 136/483 (28%) patients without archived or sufficient laboratory parameters within 14 days before GKRS1, and 7/483 (1%) patients with lost to follow-up, a total of 340/483 (71%) patients could be enrolled in this study. BM brain metastases, GKRS Gamma Knife Radiosurgery, GKRS1 first Gamma Knife radiosurgical treatment, GI gastrointestinal, GU genitourinary