One of the major challenges of teaching medical physics to Radiation Oncology residents is making didactic material practical. In a recent American Board of Radiology (ABR) post-exam survey, residents requested more clinical applicability of medical physics examination material. In this study, we hypothesized that near miss events from our department’s Incidental Learning System (ILS) could be developed into physics teaching cases. Our departmental ILS logs over 1,000 near-miss event reports per year submitted by Radiation Oncology staff. For this study 5,152 institutional ILS reports from 2/1/2012 to 12/31/2017 were evaluated. ILS categorizations relating to physics education were identified, including in-vivo dosimetry, Intensity Modulating Radiation Therapy (IMRT), Stereotactic Body Radiation Therapy (SBRT), and Image Guided Radiation Therapy (IGRT). ILS reports under each category were reviewed and selected if it involved a physicist and/or a physician. They were categorized according to the ABR Medical Physics study guide. Overall, 87 reports were identified which presented unique physics concepts. An example is the incorrect placement of bolus around the neck for head-and-neck IMRT. This report (and associated images) could be used as the basis for a teaching case on the dosimetric impact of bolus placement and potential clinical implication. The most common ILS categories for the selected cases were: planning error (n=24, 27.6%), patient setup (20, 23%), and simulation (18, 20.7%). Some reports were tagged under multiple categories and were identified multiple times. This study demonstrates the rich contextual information that is available from an ILS for physics education. Future directions include creating a bank of teaching cases. This method may also be useful in other institutions that use ILS.Abstract TU_18_3075; TableILS cases for physics education under ABR Medical Physics categorizationCategorizationN (%)SubcategorizationN (%)XIV. Assessment of patient setup and verification30 (34.5%)1. Positioning and immobilization methods and device 2. Treatment verification 3. Imaging for treatment delivery/IGRT 4. Respiratory motion management12 (40%) 11 (36.7%) 12 (40%) 13 (43.3%)XII. Treatment planning, ICRU, and beam-related biology30 (34.5%)1. 3D planning, non-coplanar beams 4. Treatment planning systems 5. Plan evaluation 6. SBRT 7. TBI1 (3.3%) 5 (16.7%) 2 (6.7%) 10 (33.3%) 16 (53.3%)IX. Dosimetry of photon beams in a patient24 (27.6%)1. Corrections for patient contour 2. Corrections for tissue inhomogeneities 3. Dose within and around an inhomogeneity 4. Matching of adjacent fields 5. Wedges 6. Parallel-opposed beams 7. Entrance dose and exit dose, including beam-modifying devices 8. Isodose distributions for multiple beams, including mixed modality and arc therapy 9. Compensators for photon beams 10. Off-axis factors8 (33.3%) 6 (25.0%) 4 (16.7%) 2 (8.3%) 1 (4.2%) 2 (8.3%) 6 (25.0%) 1 (4.2%) 5 (20.8%) 3 (12.5%) Open table in a new tab