Vision Loss Following High-Dose Proton-Based Radiotherapy For Skull-Base Chordoma And Chondrosarcoma

•Radiotherapy dose escalation for skull-based chordoma and chondrosarcoma can put critical adjacent structures at risk, specifically the anterior optic pathway, potentially causing toxicities such as vision loss.•We analyzed patients treated with high-dose conformal proton-based radiation therapy for chordoma and chondrosarcoma and observed a 5-year incidence of vision loss of 2.1%.•Despite the high radiotherapy dose delivered to patients with skull-base chordoma and chondrosarcoma, the rate of vision loss with high-dose proton therapy is low and no events occurred in those who received a maximum dose under 60GyRBE.