. Published in the Green Journal, this study by the Heidelberg group reported treatment outcomes of 82 patients with inoperable or incompletely resected sacral chordomas (87% primary and 13% recurrent) treated with proton (n=41) and carbon ion (n=41) to a total dose of 64 Gy (RBE) in 16 fractions, 5-6 fractions per week. The median follow-up of the surviving patients was 44.7 months, and the 2-year and 4-year OS rates were 96% and 81%; the LPFS after 2-year and 4-year was 84 % and 70 %, respectively. There was no significant difference between the treatment groups. There were five grade 4 wound healing disorders (6%) including three in the proton arm and two in the carbon ion arm. The authors concluded that this hypofractionation with 16 fractions of 4 GyRBE per fraction can yield promising response rates, however, local control was not sustained.