Evaluating Current Prognostic Factors for Brain Metastases of Patients with Primary Lung and Breast Cancer Receiving Cranial Radiotherapy- A Single Center Study

OBJECTIVEBrain metastases (BM) are a serious cause of morbidity and mortality in patients with solid tumors. Due to improvements in local and systemic therapies, there is a need for novel prognostic factors. Herein, we aimed to evaluate the oncological results and current prognostic factors for BM in patients with breast and lung cancer, receiving cranial radiotherapy (RT).METHODSMedical records of 147 patients who were diagnosed with lung or breast cancer and underwent cranial RT at our clinic between 2011 and 2021 were evaluated retrospectively.RESULTSThe median follow-up was 15 months (3-90 months). Local control rates for irradiated BM were 80% and 76% in patients receiving stereotactic RT and whole brain RT, respectively. Leptomeningeal metastasis (LM) developed in 24 patients (16%) during follow-up and, 87.5% of them had an infratentorial lesion. The 1-and 2-year overall survival (OS) and, intracranial progression-free survival rates were 57% and 36%, 30%, and 17%, respectively. Low-and intermediate-risk BM-velocity (BMV) is associated with better OS. None of the patients experienced severe (& GE;grade 3) acute toxicity.CONCLUSIONPrimary tumor histology, number, and localization of BM, treatment modality, extracranial disease status, development of radionecrosis, LM during follow-up, and BMV are important prognostic factors on survival in BM of patients diagnosed with lung and breast cancer. In the age of precision medicine, it is more crucial than ever to define and validate novel prognostic factors. Our findings contribute to justifying the addition of radionecrosis and BMV to predictive models.