Using virtual reality (VR) technology such as head-mounted displays, users can be immersed in a virtual world and perceive it as reality. In radiation therapy departments, pretreatment patients and students rarely observe treatment rooms and treatment devices, making it difficult to understand the overall flow of radiation therapy. In this study, to facilitate the understanding and teaching of radiation therapy, we suggest the implementation of VR technology and develop software compatible with VR to enable a pertinent comprehension of radiation therapy. With versatility and accessibility in mind, the software is developed as an application for Android and iOS devices.

Omnidirectional movies in treatment rooms were acquired from both the patient view and a third-person view using an omnidirectional camera. The Android/iOS devices used were AQUOS R (SHARP), iPhone 7 Plus (Apple), and iPad air (Apple). The software was developed using Unity 2018.4.7f (Unity Technologies). The main components of the software were as follows: (i) a home window featuring a user interface with which people can access arbitrarily rooms by tapping on floor maps or a list of treatment rooms, (ii) a snapshot mode providing 2D images of a treatment room as a slide show, and (iii) a movie mode displaying omnidirectional movies from the patient view or a third-person view. The virtual radiation therapy experience was executed by attaching the Android/iOS devices to 3D VR goggles (SAMONIC).

The main components of the application operated in good conjunction on the Android/iOS devices, and live viewing in the virtual world ran smoothly with the VR technology. However, there were resolution limitations due to the specs of the camera and the devices. It will therefore be necessary to adjust the resolution and the frame rate according to the performance of the relevant devices. The application is instructive for both patients and students because the virtual radiation therapy experience is immersive when using the VR technology. In addition, the developed software can transfer data in a single package and has the ability to substitute images and omnidirectional movies with those appropriate for diagnostic radiology and nuclear medicine departments. Therefore, the developed application is highly versatile.