IMRT verification using a radiochromic/optical-CT dosimetry system

摘要

The present work represents our first experiences relating to IMRT verification using a relatively new 3D dosimetry system consisting of a PRESAGE~(TM) dosimeter [3,4] (Heuris Inc, Pharma LLC) and an optical-CT scanning system (OCTOPUS~(TM) -^sMGS Inc). The work builds in a step-wise manner on prior work in our lab. The first step was a detailed investigating of the basic dosimetric properties of PRESAGE~(TM) on small volumes using an efficient in-house linear laser scanning system [4,5]. This was followed by application of a large volume PRESAGE dosimeter to verify a simple 3D dose-distribution [6], known to be well modelled by the planning system (ECLIPSE). Comparison of measured and planned distributions enabled evaluation of the PRESAGE~(TM)/OCTOPUS~(TM) dosimetry system. Confidence was further established by comparison with secondary independent measurement by EBT film. All these investigations confirmed the accurate performance of PRESAGE~(TM)/OCTOPUS~(TM) system, and provided a solid foundation to proceed to the present application: IMRT 3D dose verification.