Predicting Survival with Brain Metastases in the Stereotactic Radiosurgery Era: are Existing Prognostic Scores Still Relevant? Or Can we do Better?

Survival after Stereotactic Radiosurgery in the Era of Targeted Therapy: Number of Metastases No Longer Matters

“…BM number groups were pre-planned to provide the best match with the existing literature (see Introduction), and analyses were pre-specified. For multivariable analysis, age, gender, Karnofsky performance status (KPS), histology, molecular subtype, and total intracranial disease volume were analysed—each having been incorporated into published BM prognostic tools [ 16 , 30 , 31 , 32 , 33 ]. Continuous variables such as age and total intracranial tumour volume were categorised according to groups used in prognostic scoring systems.…”

“…Many newer systemic therapies penetrate the brain with good intracranial activity [ 4 , 5 , 6 , 7 , 8 ], such that combining and sequencing multi-modal BM treatment is becoming a key area of interest [ 9 ], with at least 15 trials currently in progress combining SRS with immune checkpoint inhibitors [ 10 ]. In the 1970s, median survival after the development of BMs was 3–4 months with whole brain radiotherapy (WBRT) [ 11 ] (with a significant risk of neuro-cognitive decline and a reduction in quality of life) [ 12 , 13 ], rising to 6 months at the time of the first SRS randomised control trial in 2004 [ 14 ] and to over 10 months a decade later [ 13 , 15 ], with many patients now living for years after diagnosis of BMs [ 16 ].…”