A rotatable targeting magnet apparatus and method of use thereof is described where the rotatable targeting magnet rotates independently of a beamline arc at the end of the beamline arc, where the arc is after an accelerator and before the patient in a cancer therapy system. The rotatable targeting magnet directs the charged particle beam, such as vertically, using applied current to the targeting magnet while rotation of the magnet allows scanning across the tumor. Rotation of the patient relative to the charged particle allows distribution of trailing Bragg peak energy within and/or circumferentially about the tumor.