[Evaluation of the Position Matching Accuracy for Radiological Technologists and Radiation Oncologists in...

The promotion of task-shifting and task-sharing to facilitate work style reform for physicians has enabled radiological technologists (RTs) to perform primary matching in image-guided radiotherapy. The purpose in this study is to evaluate the position matching accuracy of RTs and radiation oncologist (ROs).

Position matching was performed by four RTs and two ROs (RO-A and B). To evaluate the accuracy of the observer's position matching, five cases each were identified for the head, neck, chest, and pelvic regions in two-dimension planar images (2D/2D), and for the prostate in three-dimensional (3D) images (CBCT). Manual position matching was performed using the offline matching of the position matching analysis software at a position moved by 3-7 mm in the XYZ directions from the treatment position at the time of treatment. Inter-observer position matching accuracy was evaluated by calculating the difference between the treatment position and the matching position, and by calculating a 3D vector from the above difference.

The differences between the irradiation position and the reference position were within ±1.0 mm for 2D/2D and within ±1.5 mm for CBCT for the four RTs, while the maximum differences for RO-A were 3.0 mm and 3.5 mm, respectively. For 3D vectors, in 2D/2D, the values for four RTs and RO-B were 0.1-0.6 mm, compared to RO-A was 1.2-1.7 mm, and in CBCT, the values for four RTs were 0.3-0.7 mm, compared to the two ROs' were 1.3 mm and 1.4 mm.

The position matching accuracy of our RTs was not inferior to that of ROs, confirming that primary matching by RTs is clinically acceptable.