Quality Assurance of IMRT delivery systems – Varian

Introduction Intensity modulated radiation therapy (IMRT) provides the means for improved treatment for a wide variety of cancers. Piggybacked onto 3DCRT and MLC technologies, IMRT has developed quickly, but will undoubtedly see improvements in core hardware and software as well as in peripheral applications such as record and verify, gating, etc. At the core, individual treatment centers should expect a learning curve for understanding novel treatment planning and quality assurance (QA) issues. The urge to implement IMRT at individual therapy centers should be tempered while these issues come into focus and are addressed at each center. This presentation will discuss issues affecting dose calculation and delivery, i.e., the commissioning as well as routine QA of the Varian MLC, to provide SegmentedMLC (step and shoot) and DynamicMLC (sliding window) treatments. The QA program at MSKCC has evolved over seven years of clinical IMRT experience using DMLC.