Evaluating Digital Verification Images by Radiation Therapists and Radiation Oncologists. Do We Still Agree?

Abstract

In radiation therapy, verification images are taken to ensure correct field and patient positioning. A previous study examining the concordance between radiation therapists (RTs) and radiation oncologists (ROs) when evaluating hard copy verification films found excellent agreement. There was very little in the published literature about how this information could be transferred to digital imaging field verification. This study was undertaken to address this gap and also to confirm that the process of digital imaging would maintain a high level of agreement for quality assurance.

In practice, at the Toronto Sunnybrook Regional Cancer Centre, images are stored in Multi-Access®, as well as the evaluation and any subjective comments regarding these images.

A database of 14,721 images was acquired from a wide variety of disease sites and analyzed. A total of 5,174 true image pairs were evaluated for concordance between the ROs and RTs and overall, there was a 90 percent agreement.

Rates of agreement are high; however, a true gold standard for image verification has yet to be established. With the evolution to image guided radiotherapy, transferring the responsibility of image approval to RTs would certainly be beneficial, however it will be up to individual centres to establish their own policies surrounding treatment field verification.