Computer planning of stereotactic Iodine- 125 brachytherapy

A computer program is described for planning accurate positioning of catheters containing radioactive Iodine-125 seeds for the treatment of recurrent malignant brain tumours. A stereotactic reference frame is fitted to the patient’s head and cross-sectional images acquired using a CT scanner. Images are transferred onto a computer and a three dimensional model of the head, tumour and frame constructed. A 3D cursor is used to mark catheter trajectories. The radiation dose distribution is calculated and displayed in two and three dimensions for various combinations of seed activity and position. The interactive 3D graphics and fast computation enables efficient optimization of plans