A computer implemented method of developing a radiation treatment plan comprising spot scanning of a treatment target comprising accessing information associated with a patient and information pertaining to a radiation delivery machine. The method further comprises determining an area associated with the treatment target, wherein the area comprises a plurality of spots and computing a weighting for each spot of the plurality of spots, wherein the weighting is associated with a number of protons delivered at a respective spot. Further, the method comprises computing timing related parameters based on information retrieved from the radiation delivery machine and determining a transition dose delivered by the radiation delivery machine during the transition from one spot to another spot when irradiating the treatment target.