Robotic stereotactic radiosurgery with CyberKnife - brain metastases and fibrinolysis.

Objectives: Deviations in haemostasis are found in about 50 % of patients with cancer and up to 90% of those with metastatic disease. Many studies investigate the dynamics of the processes of coagulation and fibrinolysis and their role as a predictor of therapeutic response, early relapse, or metastasis risk.

Background: To investigate the serum levels of urokinase plasminogen activator (uPA) in patients with brain metastases treated with robotic stereotactic radiosurgery (SRS) with CyberKnife.

Material and methods: Serum levels of urokinase plasminogen activator (uPA) were measured in 66 patients with solid tumours, divided into two groups, with oligometastatic disease and brain metastases. In this prospective longitudinal study, the serum levels of uPA were measured before starting the therapy and at the first, third, and sixth months after patients were irradiated with the CyberKnife system.

Results: Analysis of serum uPA levels in the post-treatment period showed a statistically significant decrease between the baseline and the 6 months post-treatment time point in both patient groups. The baseline value of serum uPA in the group with lung cancer decreased by 62.7 %, and in the group with other types of cancer - by 60 %. Despite the significant reduction of serum uPA levels 6 months after the treatment, the levels remained significantly higher in both groups than in healthy controls.

Conclusion: Ongoing research on uPA and cancer will enrich our knowledge and expand the possibilities for clinical utilization of the marker in the oncology setting (Tab. 2, Ref. 18).