  Contouring is an indispensable step in Radiotherapy (RT) treatment planning.
However, today's contouring software is constrained to only work with a 2D
display, which is less intuitive and requires high task loads. Virtual Reality
(VR) has shown great potential in various specialties of healthcare and health
sciences education due to the unique advantages of intuitive and natural
interactions in immersive spaces. VR-based radiation oncology integration has
also been advocated as a target healthcare application, allowing providers to
directly interact with 3D medical structures. We present VRContour and
investigate how to effectively bring contouring for radiation oncology into VR.
Through an autobiographical iterative design, we defined three design spaces
focused on contouring in VR with the support of a tracked tablet and VR stylus,
and investigating dimensionality for information consumption and input (either
2D or 2D + 3D). Through a within-subject study (n = 8), we found that
visualizations of 3D medical structures significantly increase precision, and
reduce mental load, frustration, as well as overall contouring effort.
Participants also agreed with the benefits of using such metaphors for learning
purposes.
