DoseRAD2026 Challenge dataset: AI accelerated photon and proton dose calculation for radiotherapy. - Fan Xiao; Nikolaos Delopoulos; Niklas Wahl; Lennart Volz; Lina Bucher; Matteo Maspero; Miguel Palacios; Muheng Li; Samir Schulz; Viktor Rogowski; Ye Zhang; Zoltán Perkó; et al. (CoRR, 2026)