Gyro Knife (also referred to as a Gyro radiosurgery system) is a full-body stereotactic radiotherapy device that uses multiple converging beams from flexibly rotating angles to concentrate a high radiation dose on the tumour while protecting surrounding healthy tissue. Unlike Gamma Knife (which has a fixed irradiation geometry), Gyro Knife has a robotic arm that rotates 360 degrees, enabling treatment of tumours in a wider range of locations and complex shapes. Primary indications include small brain tumours, brain metastases, acoustic neuromas, arteriovenous malformations (AVM) and selected spinal tumours. Treatment typically requires only 1–5 sessions depending on tumour size, with no open surgery required. Educational content only — does not replace medical advice.