Why is linear accelerator used in radiotherapy?

The machine creates radiation outside the body and sends it toward the area selected by the radiation oncologist. Imaging and treatment planning help define the target, while the machine can adjust the beam direction, shape, and intensity. This allows treatment to be fitted to the size and position of a tumour or surgical bed. The beam is delivered during short appointments, and the machine does not place radioactive material inside you.

The choice of machine depends on the treatment plan, the body area, the goal of treatment, and how close the target is to sensitive organs. A linear accelerator may be used for several radiotherapy techniques, but the treatment team still checks positioning before each session.

Before treatment, you may have imaging, a planning appointment, and positioning supports to help you lie in the same way each time. During delivery, you usually remain still while the machine moves around you; it does not touch your body. Tell the team about implanted devices, pregnancy or possible pregnancy, and difficulty holding a position. Follow the skin-care, activity, and medication instructions given for your specific treatment.

Contact your radiotherapy team if you develop worsening skin reaction, repeated vomiting, difficulty swallowing, new breathing trouble, severe pain, or symptoms that prevent eating, drinking, sleeping, or attending treatment. Seek urgent medical help for sudden weakness, confusion, heavy bleeding, or severe breathing difficulty. The warning signs depend on the body area being treated, so use the contact number provided by your centre.

Ask which area will be treated, how positioning will be checked, what technique the plan uses, which nearby organs are being protected, and which symptoms should be reported between appointments.