Implementation of the Varian EDW into a commercial RTP system.

An enhanced dynamic wedge system (EDW) has been installed onto our Clinac 600C (6 MV) linear accelerator. This paper addresses and describes the measurements taken and subsequent analysis required to enable the planning of EDW using our commercial radiotherapy treatment planning (RTP) system. This implementation into a 'closed' commercial system is performed without the use of specialized measurement equipment or the necessity of introducing new calculation algorithms and is therefore independent of the RTP manufacturer. We consider that, for incorporation of techniques such as EDW into routine clinical use, a simple verifiable method of inclusion into the RTP system must be achieved. This paper also presents a methodology for quality control of dynamic fields chosen for clinical use which is quick and easy to use by virtue of its use of film dosimetry. We present the method of film calibration used in this work.