This study reported early outcomes of 21 adult pelvic Ewing sarcoma treated with PT (n=18 primary disease) to a total dose of 45-60 GyRBE and with carbon ion (n=3 recurrent disease). At the end of particle therapy, grade 1-2 skin reactions (n = 16/21) and fatigue (n = 9/21) were the main reported symptoms. After a median follow-up of 21 months, the 2-year LC, DC and OS were 76%, 56% and 86%, respectively. The authors stated that this first clinical outcomes were promising; however, further long-term follow-up is needed.