A control circuit operably couples to a memory having historical information stored therein. This historical information comprises information regarding delivered radiation doses to non-targeted patient volumes for a plurality of different volume presentations. The control circuit iteratively optimizes a radiation-treatment plan for a specific plan using that historical information. The aforementioned historical information can comprise delivered-dose metrics as correspond to different relative distances within given patients. The control circuit can employ such information to determine, for example, an estimated dosage (including, if desired, a corresponding range of estimated dosages) for at least one volume within the specific patient at a specific distance from a specific point of reference. The control circuit can compare such historical information against radiation-treatment plan optimization results to qualitatively assess the radiation-treatment plan optimization results.