Multicenter collaborative quality assurance program for the province of Ontario, Canada: first-year results

The objective of this work was to develop a collaborative quality assurance (CQA) program to assess the performance of intensity modulated radiation therapy (IMRT) planning and delivery across the province of Ontario, Canada.

The CQA program was designed to be a comprehensive end-to-end test that can be completed on multiple planning and delivery platforms. The first year of the program included a head-and-neck (H&N) planning exercise and on-site visit to acquire dosimetric measurements to assess planning and delivery performance. A single dosimeter was used at each institution, and the planned to measured dose agreement was evaluated for both the H&N plan and a standard plan (linear-accelerator specific) that was created to enable a direct comparison between centers with similar infrastructure.

CQA program feasibility was demonstrated through participation of all 13 radiation therapy centers in the province. Planning and delivery was completed on a variety of infrastructure (treatment planning systems and linear accelerators). The planning exercise was completed using both static gantry and rotational IMRT, and planned-to-delivered dose agreement (pass rates) for 3%/3-mm gamma evaluation were greater than 90% (92.6%-99.6%).

All centers had acceptable results, but variation in planned to delivered dose agreement for the same planning and delivery platform was noted. The upper end of the range will provide an achievable target for other centers through continued quality improvement, aided by feedback provided by the program through the use of standard plans and simple test fields.