Novel prognostic classification predicts overall survival of patients receiving salvage whole-brain radiotherapy for recurrent brain metastasis from breast cancer: A recursive partitioning analysis (KROG 16-12) - Jae Sik Kim; Kyubo Kim; Wonguen Jung; Kyung Hwan Shin; Seock-Ah Im; Yong Bae Kim; Jee Suk Chang; Doo Ho Choi; Haeyoung Kim; Yeon Hee Park; Dae Yong Kim; Tae Hyun Kim; et al. (Breast, 2021)