# Impact of frailty on outcomes of inpatient stereotactic radiosurgery for brain metastasis: a national readmission database analysis 2016–2020

## TL;DR

This study shows that frailty in older patients undergoing brain cancer treatment leads to worse outcomes like higher death rates and longer hospital stays.

## Contribution

This is the first population-based analysis linking frailty to outcomes in stereotactic radiosurgery for brain metastasis.

## Key findings

- Frail patients had 2.39 times higher in-hospital mortality after SRS.
- Frailty was associated with longer hospital stays and higher costs.
- Frail patients had a 47% higher 30-day readmission rate.

## Abstract

It is not clear how frailty may affect the outcomes of stereotactic radiosurgery (SRS) for brain metastasis. This study aimed to evaluate the impact of frailty on clinical outcomes in patients ≥ 60 years old who underwent SRS for brain metastasis from a population-based perspective.

Data were extracted from the National Readmission Database (NRD), 2016 to 2020. Inclusion criteria were ≥ 60 years old with brain metastasis who underwent SRS. Frailty was assessed using the modified Frailty Index (mFI), derived from 11 clinical conditions. The primary outcomes were in-hospital mortality, length of hospital stay (LOS), total hospital costs, and 30-day and 90-day readmission rates. Logistic and linear regression models were used to assess the association between frailty and outcomes.

A total of 904 patients (mean age: 71 years, 53% male) were included, of which 17.5% were defined as frail. After adjusting for demographic, clinical, and hospital-related factors, frailty was significantly associated with increased in-hospital mortality (adjusted odds ratio [aOR] = 2.39, 95% confidence interval [CI]: 1.16–4.92), longer LOS (adjusted Beta [aBeta] = 2.61 days, 95% CI: 1.95–3.28), higher total costs (aBeta = $36.04 thousand USD, 95% CI: 28.84–43.23), and higher 30-day readmission rate (aOR = 1.47, 95% CI: 1.02–2.11).

Frailty independently predicts poorer outcomes in older adults undergoing SRS for brain metastasis, including higher mortality, longer hospital stays, increased hospital costs, and increased 30-day readmission rate. These findings highlight the importance of incorporating frailty-informed risk stratification and perioperative care planning to optimize patient outcomes.

Not applicable.

The online version contains supplementary material available at 10.1186/s13014-025-02750-4.