Preoperative Stereotactic Radiosurgery for Brain Metastases: A Single-Institution Experience.

Aim: To report a single center experience in preoperative stereotactic radiosurgery (SRS) in patients with metastatic brain tumors.

Material and methods: We identified 18 patients who underwent preoperative stereotactic radiosurgery (SRS) in our clinic between 2015 and 2021. Two patients were lost to follow-up and therefore were excluded from clinical outcome analyses. SRS was administered using the CyberKnife system.

Results: The median volume of index lesion was 14,19 mL (range 3,13-40,84). SRS was performed in median 1 fraction (range 1-2) to a median prescription dose of 15 Gy (range 12-17). Gross total resection was achieved in 14 (77.8%) patients. The median follow-up was 15 months (range 1-87). Median cancer specific survival (CSS) was 31 months. 6-, 12- and 24- months local control (LC) rates were 91%, 79% and 68%, respectively. Better gross tumor volume coverage was associated with better LC (p=0.01). 6-, 12- and 24- months distant brain control (DBC) rates were 82%, 58% and 47%, respectively. The infratentorial location of index lesion was associated with worse DBC (p=0.026). None of the failures were in the pattern of leptomeningeal dissemination (LMD). Grade IV symptomatic radionecrosis (RN) was reported in a single case. Three patients experienced fatal (grade V) post-operative complications.

Conclusion: Preoperative SRS approach, which provides the advantage of low rates of RN and LMD, is a meritorious alternative strategy in the treatment of brain metastasis. Care must be given to better assessment of surgical mortality and the selection of appropriate patients for this treatment approach.