These teachings provide for administering a radiation treatment plan to a patient in a single radiation treatment session using a multi-leaf collimator that is comprised of pairs of selectively movable collimating leaves. By one approach this comprises administering a sequential plurality of modulated radiation doses to the patient, where the sequential plurality of modulated radiation doses comprises at least a substantial majority of a planned total radiation dose for the radiation treatment session and where each modulated radiation dose is administered while modulating a radiation beam with the multi-leaf collimator using a curtain pattern (or, perhaps more typically, a plurality of curtain patterns).
