Improving a Scissor-Action Couch for Delivering Micro MLC-based Conformal Arc Radiotherapy and Radiosurgery

Abstract

We develop a method to improve the setup accuracy of a Varian Clinac 6/100 couch for delivering dynamic arc therapy using a tertiary microMLC system. Several immobilization devices are designed and constructed to improve mechanical stability and isocenter alignment of the couch. These include turn-knob harnesses, double-track alignment plates, and a drop-in rod that latched the couch to the concrete floor. These add-on components minimized the inter-component motion of the scissor elevator of the couch to allow consistent treatment setups. The isocenter alignment of the couch was improved to be within 1 mm with the devices. The couch has been used for over 50 dynamic modulated arc beam treatments at our institution.