PurposeAchieving gender equity in radiation oncology is an important goal as a smaller proportion of women enter radiation oncology residency compared to those graduating medical school. As invited speaking opportunities at academic medical conferences are vital for promotion/tenure, we investigated the prevalence of all-men panels (“manels”) at ASTRO and CARO Annual Meetings. Methods and MaterialsUsing ASTRO and CARO online meeting programs, 2018-2021 faculty information was obtained, including gender, panel role (chair vs. non-chair), type of session, and topic. Primary outcomes included percentage of manels and proportion of women panelists over time. Representation of women among chairs was also evaluated. ResultsOver the 4-year study period across both conferences, there were a total of 765 panel sessions with 2,973 faculty members, of which 1,287 (43.3%) were women. Of these, 127/765 (16.6%) were manels. ASTRO meetings had 169/2742 (42.6%) women faculty members and 107/680 (15.7%) manels, while CARO meetings had 118/231 (51.1%) female faculty and 20/85 manels (23.5%). From 2018 to 2021, the proportion of manels decreased, at ASTRO and CARO from 25.6% to 8.2% (p<0.001) and from 29.6% to 15.0% (p=0.130), respectively. The role of chair was majority male in every year from 2018 to 2021 at ASTRO (58.6% overall), but more balanced at CARO (48.0% overall). Among session types, the highest proportion of manels was observed for scientific sessions (19.1%, p=0.011) at ASTRO and leadership sessions (29.4%, p=0.533) at CARO. The lowest proportion of women panelists were on genitourinary cancer topics at ASTRO (31.9%, p=0.018) and physics topics at CARO (40.4%, p=0.085). ConclusionDuring the study period, the proportion of women panelists increased with a corresponding decrease in manels. ASTRO and CARO should strive for further involvement of women and the elimination of manels whenever possible.