The use of ultrasound to measure breast thickness to select electron energies for breast boost radiotherapy.

Ultrasound has been used in 30 patients to measure breast thickness as a means of selecting the most appropriate electron energy for the boost in breast conservation radiotherapy. When compared with electron energies selected on the basis of clinical examination, the target volume was underdosed in 21/30 patients. A major problem in the placement of an electron boost is the demarcation of the target volume.