Automating Radiotherapy Cancer Treatment: 
A Preliminary Study Using Multirate Observer-Based Control
Professor Daniel E. Davison


Department of Electrical and Computer Engineering

University of Waterloo

200-University Ave. W.

Waterloo, Ontario, Canada N2L 3G1


Abstract--For decades, doctors have been using external ionizing x-ray radiation to destroy cancerous tumours.  Traditionally, the area to be irradiated is intentionally made larger than the tumour size so that movement of the tumour and misalignment of the tumour with the x-ray beam can be accommodated.  A consequence of this practice is that some radiation is delivered to healthy organs located near the tumour, often resulting in undesirable side effects.  In this talk we present preliminary results showing how feedback control can be used so that the radiation beam tracks the tumour.  By using such a scheme, the radiation beam can be made more narrow and, hence, some healthy tissue can be spared from radiation damage, possibly reducing side effects.  The proposed control technique is based on a multirate observer system.

Friday, January 31, 2003

3:30 – 4:30 p.m.

1500 EECS