Two fractions staged Gammaknife radiosurgery for "large" cerebral metastases.

Background: Gammaknife radiosurgery (GKRS) is a valuable option to control cerebral metastases. However, the risk (adverse radiation effect (ARE))-benefit (local control (LC)) ratio switches when the target is too large.

Objective: In order to balance this ratio, two fractions staged GKRS protocol was conducted for "large" cerebral metastases.