1. A method for producing a radiation treatment plan for a patient using a radiation treatment planning system, the steps of the method comprising: (a) providing at least one image of a patient to a radiation treatment planning system; (b) identifying with the radiation treatment planning system, a target volume in the patient based on the at least one image of the patient, the target volume comprising a volume bounded by an outer boundary; (c) identifying with the radiation treatment planning system, an organ at risk (OAR) volume based on the at least one image of the patient; (d) generating with the radiation treatment planning system, a plurality of avoidance volumes based on the identified OAR volume; (e) determining with the radiation treatment planning system, a target objective based on the identified treatment volume, the target objective indicating a desired dose distribution in the target volume; (f) determining with the radiation treatment planning system, a physical objective for each of the plurality of avoidance volumes, each physical objective being based a physical capability of a radiation treatment system and indicating a desired dose gradient across the plurality of avoidance volumes; and (g) generating with the radiation treatment planning system, a radiation treatment plan by providing the target objective and physical objectives to the radiation treatment planning system, wherein with the radiation treatment planning system is programmed to generate an optimized radiation treatment plan by optimizing an objective function based at least in part on the target objective and physical objectives.