Total craniofacial photon shell technique for radiotherapy of extensive angiosarcomas of the head

Abstract

Effective radiotherapy for extensive angiosarcomas of the face and scalp is technically difficult due to the complex shape of the volume at risk, which can consist of the superficial tissues of the entire head. This work reports the details of a rotational X-ray technique used to deliver a large part of the tumour dose. The technique consists of four consecutive 90 degree arcs with changing centre blocks to protect critical midline structures. Multilevel CT based treatment planning is carried out to determine the centre block dimensions and beam weights. As a result the radiation dose is delivered with acceptable uniformity over the entire shell of superficial tissues of the head. The overall treatment combines the rotational fields with large lateral field irradiation and/or local boosts with photons or electrons. Two of three patients treated with this technique had local control of the disease until their deaths at 13 and 18 months. A third patient responded well, with only a small region of stable disease at 9 months.