Techniques for radioablation of sympathetic nerves include positioning a subject on a support in view of a volume imaging system and an ionizing radiation source; and collecting volume image data. Location of a treatment portion of a sympathetic nerve in the subject is determined based on the volume image data. Movement of the source is determined to apply a therapeutic radiation dose to the treatment portion based on the location of the treatment portion and relative location of the source to the volume imaging system. The source is operated to deliver the therapeutic radiation dose. An apparatus includes a mounting structure, an X-ray source and a shield. The source produces an X-ray beam with photon energy above one million electron volts (MeV) and not above six MeV. The shield is mounted in opposition to the source to block the X-ray beam with photon energies not greater than about six MeV.