Successful implementation of ChicaEducation system for Oncology Residency Standardized Training

Background The ability to access knowledge and skills of radiation oncology is fundamental for oncology residency standardized training. Methods This study evaluates whether or not the ChicaEducation system for oncology residency standardized training contributes to training radiation oncology medical students. As a virtual reality system for radiotherapy training, ChicaEducation system was successfully implemented. We compared the ChicaEducation system training module with a traditional training module. Whether the integration of ChicaEducation into medical teaching was intended to enhance students’ autonomic learning and comprehensive analysis was also evaluated. Results The integration of ChicaEducation system into oncology residency standardized training was valuable compared to traditional training methods and could improve radiation oncology medical students’ perceptions and understanding. ChicaEducation system training module was positive and could enhance radiation oncology medical students’ level of condence in radiation oncology. Conclusions The role of ChicaEducation system training module in delivering an ecient quantity of oncology medical education was ascertained because of its ability to visualize conceptual information within a simulated clinical environment. The ChicaEducation system may alleviate economic burdens in some hospitals and be used for training for doctors in rural areas.

held pendant which enables users to interact actively 6 . And the system loads simulated patients' computed tomography (CT) data and radiation treatment plans 7 . Medical students can see the simulated dose distributions in CT slices. Moreover, medical students can develop new radiation treatment plans personally and adjust plan parameters repeatedly and immediately. Before radiation treatment, a simulated patient could be operated and moved to the right site in the VR system according to the radiation treatment plan. When the plan is implementing, the simulated sound of the radiation beam can be heard. The ChicaEducation system was implemented for RT students in China in 2016. Radiation oncology medical students had a better handle on fundamental RT concepts, better knowledge of anatomy, simple RT delivery techniques, and building of con dence 8 . These advantages were attributed to students' hands-on ability and experience with virtual radiotherapy equipment. And students could discover, analyze, and solve problems without adversely affecting patients or equipment 9 .
However, the ChicaEducation system's use in radiation oncology medical students is less well reported. ChicaEducation system. We provide a description of the ChicaEducation system that was incorporated into radiation oncology for oncology residency standardized training. And the e ciency of ChicaEducation system training module in oncology medical education was evaluated.

Study design
This study consisted of the ChicaEducation system training module group and traditional training methods group, using survey instruments for data collection. Each group had 30 radiation oncology medical students. Students in the traditional training methods group did not receive ChicaEducation system training. And students in the ChicaEducation system training module group received ChicaEducation system training for two months.

Master of Radiation Oncology at the University of Electronic Science and Technology of China
The radiation oncology is offered as a 3-year postgraduate program, which prepares medical students for subsequent entry into clinical training (Residency Standardized Training). Traditionally, radiation oncology has been undertaken using a combination of didactic lectures tutorials conducted at university, as well as tutorials, practices, and demonstrations conducted in RT departments under the supervision of clinical radiation oncology medical students.

Participants
All 60 radiation oncology medical students at Sichuan Cancer Hospital & Institute, Sichuan Cancer Center, School of Medicine, University of Electronic Science and Technology of China were invited to participate in this study in 2019. All students were the rst year of the Standardized Training of Residents. The age of all the students ranged from 23 to 25. Informed consent was obtained from all individual participants included in the study. All data of the questionnaires collected was anonymous.

ChicaEducation system
This system was used to offer networked teaching and training opportunities for medical student education. The integration of the ChicaEducation system could supplement classroom teaching and introduce oncology medical students to virtual radiation therapy environments. Three ChicaEducation system practical sessions were developed: (1) Virtual CT system, (2) Target delineation and radiation treatment planning system, and (3) Linear accelerator simulation system. The learning objectives for each of the sessions are listed in Table 1. In the "Virtual CT systems" practical session radiation oncology students can learn organs at risk in radiation therapy and how to delineate organs at risk accurately according to anatomies. Simulated CT datasets from different anatomical sites of bodies were imported into the ChicaEducation system. The CT data contained four anatomical structures: head and neck, thorax, abdomen, pelvis regions. In the "Target delineation and radiation treatment planning system" practical session radiation oncology students can obtain target delineation and radiation treatment plans of cancers at different sites. Primary and nodal gross tumor volumes (GTVs), and primary and nodal clinical target volumes (CTVs) can be delineated based on the simulated CT images. Many radiation treatment plan systems, including the Eclipse treatment planning system (Varian, California, USA) and the Pinnacle 3 treatment planning system (Philips, Best, Holland) were employed in the ChicaEducation system. The students can see many simulated radiation treatment plans in terms of different dose prescriptions. And the students can perform a radiation treatment plan independently. Through the ChicaEducation system, students' plans can be evaluated. A better plan can be chosen by comparing different plans. The "Linear accelerator simulation system" practical session can provide an introduction to various quality control (QA) measurements. ChicaEducation system can offer linear accelerators in a life-sized virtual radiotherapy treatment room with immobilization equipment on the treatment couch. It is essential to introduce QA methods to radiation oncology medical students. QA work ows on teaching tools were offered in the ChicaEducation system. Furthermore, the students can perform QA measurements independently in the ChicaEducation system.

Student evaluation of ChicaEducation systems
Evaluations of two group students were conducted using three questionnaires ("Virtual CT system" session, "Target delineation and radiation treatment planning system" session and "Linear accelerator simulation system" session). Sixty students participated in the evaluation, and 60 completed the three questionnaires were received. In the "Virtual CT system" session in table 3, all students were asked to rate their current knowledge on the relationship of anatomy to target delineation and radiation therapy. A score of each item was on a scale of 1-5, with a score of 1 indicating poor and a score of ve indicating excellent. In the "Target delineation and radiation treatment planning system" session, some questions were shown in table 4. Students reported that the "Target delineation and radiation treatment planning system" session helped them link the theoretical knowledge to target delineation and radiation treatment planning system. Some simple questions were listed in table 5 in the "Linear accelerator simulation system" session. These questions were asked about the role of the physics of radiology course and validation of radiation treatment.

Statistical Analysis
Continuous variables were expressed as median and range. Statistical data were performed using SPSS 18.0 statistical software. Wilcoxon rank-sum tests were used for continuous variables that were not normally distributed. All tests of signi cance were two-sided, and the statistical difference was considered signi cant if P-values were <0.05.

Results
ChicaEducation system Figure 1a showed screenshots from the "Virtual CT systems" practical session in the ChicaEducation system. The visualization tools in the ChicaEducation system were used to systematically describe the region of the head and neck, concerning the patient's external view (Fig 1b) and the internal anatomy shown as CT images (Fig 1c) and 3D volumes (Fig 1d). Figure 2 showed screenshots from the "Target delineation and radiation treatment planning system" practical session in the ChicaEducation system. ChicaEducation system has included visualization of RT plans for a range of tumor sites, such as head and neck cancer, lung cancer, and prostate cancer. Examples from a patient irradiated for head and neck cancer were presented in Figure 2. Spatial modulation was achieved utilizing dynamic multileaf collimator (MLC) trajectories, which were synchronized to the gantry angle and dose rate. (Fig 2a) The dose volume histogram (DVH) of the volumetric modulated arc radiotherapy (VMAT) plan was shown in Fig 2b. The VMAT plan was based on the applied CT volume, a simulated dose volume with the same resolution and extent as the CT volume. Dose values in RT were typically visualized with a rainbow color map mapping low dose to the blue scale of the rainbow and high dose to red Fig 2c . Fig 2d presented an electronic portal imaging devices (EPIDs) image frame was used as a function of gantry angle during clinical VMAT deliveries (Fig 2d). Figure 3 showed examples of screenshots from the "Linear accelerator simulation system" practical session in the ChicaEducation system. The virtual water tank in ChicaEducation linear accelerator simulation system was displayed (Figure 3a), and it was used to create percentage depth dose (PDD) plots. Multileaf collimators (MLCs) for the selected beam in ChicaEducation linear accelerator simulation system was shown in Figure 3b. ChicaEducation linear accelerator simulation system could monitor and calibrate the placement of radiotherapy. A sample of head and neck placement was displayed in Figure  3c, and Figure 3d at different angles.

Student evaluations
The distribution of select participant characteristics was shown in table 2 in additional supporting information. There was no statistically signi cant difference in gender and age distribution between the ChicaEducation system training module group and the traditional training methods group (P > 0.05). In the "Virtual CT system" session, there was a statistically signi cant difference between the two groups in table 3. Students reported higher evaluation scores in the questionnaire in the ChicaEducation system training module group than the traditional training methods group. ChicaEducation system training group students could better connect anatomy to radiation oncology theory. In the "Target delineation and radiation" session, there was also a statistically signi cant difference between the two groups except for the evaluation of "How would you rate your understanding of 3DCRT?" in table 4. Score statistics for each of the three statements were shown in table 5 in the "Linear accelerator simulation system" session. And there was a signi cant difference in evaluation scores in this session between the two groups. The evaluation scores were higher in learning in the ChicaEducation system training module group than in the traditional training methods group.

Discussion
VR is a new technology that has been widely used in medical education in recent years. VR is an interesting form of simulation and maybe better suit for the acquisition of both knowledge and skills 10 .
Several studies have indicated the e cacy of VR in medical education for improving the clinical and procedural competence of learners compared with traditional teaching methods 9,11-12 . VR has become available for radiotherapy training, enabling medical students to learn the whole process of simulated radiation therapy without interfering with the clinical work ow. And students can repeatedly operate without the risk of making errors 1 . Furthermore, instructors can make better assessments of their students' skills through VR tools 13 .
ChicaEducation system is a VR tool that can provide training without involving patients and enable repetitive training. This paper describes our initial experience with the ChicaEducation system and introduction to ChicaEducation based practical sessions. The use of the ChicaEducation system in an educational setting has several possible bene ts to radiation oncology medical students. ChicaEducation systems training quali ed medical students better than conventional training. It may improve the knowledge and clinical skills of radiation oncology medical students. It is suggested that ChicaEducation system training remains to be used as a supplementary teaching method at the University of Electronic Science and Technology of China. Our results demonstrated that the ChicaEducation system was a useful learning and training tool. As can be seen from the questionnaire, students have a higher interest in learning in the ChicaEducation system training module group than that to traditional training methods group. The radiation oncology medical students received ChicaEducation system training had more enthusiasm for radiation oncology education. Their interests were also increased through the ChicaEducation system. After ChicaEducation system training, the radiation oncology medical students quickly understood the complex process of radiation therapy. The ChicaEducation system also provided a detailed description of the process of simulated radiation therapy. Besides, the ChicaEducation system provided a more exible way of teaching. As the ChicaEducation system was delivered into a classroombased setting, students could operate repeatedly and gradually master the process of simulated radiation therapy and do not think about making mistakes. As a complementary training along with main training, ChicaEducation system training can never replace the traditional training in the real environment. However, there were some limitations to this study. The rst one was a small sample size, which reduces the ability to generalize results to a greater population. Secondly, it was a one-time educational experience. In addition, the results of the evaluation questionnaires are subjective. It was di cult to assess students' knowledge. Due to the difference in students' knowledge and skills, the bias may occur in the results that the students chose.

Conclusion
Our experience with the ChicaEducation system in the radiation oncology medical education at the University of Electronic Science and Technology of China was e cient and demonstrates the viability of the ChicaEducation system for radiation oncology medical student education. The integration of the ChicaEducation system into the medical curriculum can be valuable in addition to the traditional methods.

Availability of data and materials
The datasets used and/or analyzed during the current study are available from the corresponding author on reasonable request.
Authors' contributions Q Yao: acquisition of data and analysis, manuscript writing and nal approval, H Wu: acquisition of data and analysis, manuscript writing and nal approval, L Zou: data analysis and nal approval, HT Lan: data analysis and nal approval, SC Luo: data analysis and nal approval, S Lu: data analysis and nal approval, XF Li: statistical analysis and nal approval, JY Lang: Study concept, design, acquisition of data and analysis, manuscript writing and nal approval, C Xu: Study concept, design, acquisition of data and analysis, manuscript writing and nal approval. Table 1 Learning objectives for "Virtual CT system", "RT treatment planning system" and "Linear accelerator simulation system" practical sessions At the completion of the practical session, students should be able to: Virtual CT systems 1. Identify the major organs in the head and neck, thorax, abdomen, pelvis 2. Describe the major organs in the head and neck, thorax, abdomen, pelvis, with relation to    Screenshots from the "Target delineation and radiation treatment planning system" ChicaEducation system practical session, showing MLC trajectories of head and neck cancer VMAT plan(a), DVH of VMAT plan (b), Dose values (c) and EPIDs image frame (d).