The indication of palliative whole-brain radiotherapy for patients with brain metastases: a simple prognostic scoring system in the era of stereotactic radiosurgery

Background Stereotactic irradiation has become the mainstay treatment for brain metastases (BM), and whole-brain radiotherapy (WBRT) is often used for symptom palliation. However, the survival time of patients with BM undergoing palliative WBRT (pWBRT) is limited, making it difficult to select patients who should receive treatment. Methods We collected patient data from 2016 to 2022 at the Shizuoka Cancer Center and retrospectively analyzed the factors related to survival time. Overall survival (OS) was defined as the survival time after WBRT. Results A total of 301 patients (median age, 66 years) who underwent pWBRT were included. The primary cancers were lung, breast, gastrointestinal tract, and other cancers in 203 (67%), 38 (13%), 33 (11%), and 27 (9%) patients, respectively. Median OS of all patients was 4.1 months. In the multivariate analysis, male sex (hazard ratio [HR]:1.4), Karnofsky Performance Status (KPS) <= 60 (HR:1.7), presence of extracranial metastasis (ECM) (HR:1.6), neutrophil-lymphocyte ratio (NLR) >= 5 (HR:1.6), and lactate dehydrogenase (LDH) >= upper limit of normal (ULN) (HR:1.3) were significantly associated with shorter OS (all P < 0.05). To predict the OS, we created a prognostic scoring system (PSS). We gave one point to each independent prognostic factor. Median OS for patients with scores of 0-2, 3, and 4-5 were 9.0, 3.5 and 1.7 months, respectively (P < 0.001). Conclusions Male sex, KPS <= 60, presence of ECM, NLR >= 5, and LDH >= ULN were poor prognostic factors for patients with BM undergoing pWBRT. By PSS combining these factors, it may be possible to select patients who should undergo pWBRT.