Electron field within an electron field treatment of the scalp or other curved surfaces

The treatment of a curved surface is a challenge for radiation therapy. This patient had previous treatment with electrons to the "skull cap" area for malignant melanoma. The current task was to design a treatment schema to include the rest of the scalp while avoiding the skull cap. Opposing lateral 6-MeV electron fields were used, as well as two anterior 6-MeV electron fields, one field within the other, to produce an acceptable radiation dose to the tumor volume.