KLK3 and prostate carcinoma: Clinical and Treatment Characteristics of Prostate Cancer Patients with Brain Metastases BrM: brain metastasis; CSPC: castrate-sensitive prostate cancer; CRPC: castrate-resistant prostate cancer; ECOG: Eastern Cooperative Oncology Group; GPA: Graded Prognostic Assessment; PC: prostate cancer; PSA: prostate-specific antigen; SRS: stereotactic radiosurgery; VMAT: volumetric modulated arc therapy; WBRT: whole brain radiotherapy