A Need for Contouring Education in Latin America: Evaluating an E-contouring Experience with Novel Reporting of DICE Metrics

Abstract

As the technology for radiation oncology advances, therapy is able to be delivered in a more conformal fashion with a goal of both greater targeting of the tumor as well as avoidance of healthy structures. However, greater conformality requires the ability to correctly identify and contour both tumor volumes and organs at risk. One method of delivering content, particularly for practitioners abroad, is through e-contouring sessions. E-contouring allows for interactive didactic sessions allowing participants to see contouring of structures in real time. This represents the first international education intervention in Latin America utilizing e-contouring reporting DICE coefficients. An e-contouring workshop was undertaken in Lima, Peru at the 2018 eCancer conference. Registered students had access to an online platform beginning two weeks before the workshop along with case vignettes. Seven cases were presented with indications for radiation: locally advanced lung, lung SBRT, post-operative cervix, anaplastic astrocytoma, hippocampal sparing whole-brain, and two cases of linear accelerator based stereotactic radiosurgery for brain metastases. Each case listed various structures to contour for designated slices. Concordance of student responses with educator contours was measured using DICE coefficients. Post-educational intervention, students were given two weeks to redo homework assignments with intent to compare DICE coefficients with paired t-test. Fifty-five people registered for the contouring workshop and 13 (24%) completed homework pre-workshop. For the four non-palliative cases, the total mean DICE coefficient was 0.58. Average DICE scores pre-workshop for the entire case, which included organs at risk, and tumor volumes, are shown in the table. Of the 13 students who completed homework pre-workshop, only one student attempted the post-intervention homework with no significant change in DICE score. We present the first e-contouring experience with DICE coefficients in Latin America. Approximately a quarter of the registered students completed homework. The remaining pre-intervention scores serve as a diagnostic and highlight the importance of a need for contouring education with a majority of scores below 0.70. Unfortunately, participation in pre-assessment homework was low and post-assessment homework was minimal which does not allow for meaningful assessment of retained knowledge. Future e-contouring courses in Latin America would benefit by completing post-assessments at the time of workshop.Abstract TU_3_2919; Table 1CaseDICE scoreLocally Advanced Lung Cancer0.52GTVp0.85GTVn0.48SBRT Lung0.63ITV0.49Post-op Cervix0.52CTV0.45Anaplastic Astrocytoma0.66CTV0.74 Open table in a new tab