A photon therapy delivery system can deliver radiation therapy to a patient via a photon beam. The system can utilize a controller configured to facilitate delivery of radiation therapy via a photon beam and also a particle beam. This can include receiving radiation therapy beam information for radiation therapy treatment of a patient utilizing the particle beam and photon beam. Also, patient magnetic resonance imaging (MRI) data can be received during the radiation therapy treatment. Utilizing the patient MRI data, real-time calculations of a location of dose deposition for the particle beam and for the photon beam can be determined taking into account interaction properties of soft tissues through which the particle beam passes.