Brain tumors account for a significant disease burden, and surgical removal remains the primary treatment. However, postoperative complications are common and can affect recovery and survival. While tumor-related factors are traditionally used to predict outcomes, patient-related factors such as frailty — a condition reflecting reduced physiological reserve — may also play an important role. Frailty has been associated with increased postoperative complications, prolonged hospital stay, mortality, and poorer functional recovery in various surgical populations.

In neurosurgical oncology, most available evidence is retrospective, and prospective data are limited.

This prospective single-centre cohort study aims to evaluate the association between preoperative frailty (assessed using the Clinical Frailty Scale [CFS] and 5-item Modified Frailty Index [mFI-5]) and short-term outcomes in adults undergoing elective brain tumor surgery. The primary objective is to determine the relationship between frailty and 30-day postoperative neurological and medical complications. Secondary objectives include assessing hospital stay duration, functional recovery (Karnofsky Performance Status), 90-day mortality, and discharge disposition, as well as evaluating the predictive accuracy of frailty tools.

A total of 415 adult patients undergoing elective craniotomy for primary or metastatic brain tumors will be enrolled. Frailty will be assessed preoperatively using standardized tools. Postoperative outcomes will be recorded by blinded investigators. Multivariable analysis will be performed to adjust for confounding factors.

This study aims to validate frailty assessment as a practical tool for perioperative risk stratification and to support individualized care in brain tumor surgery.