What should you know about a linear accelerator machine?

The machine, often called a LINAC, creates radiation used to damage cancer cells in a selected part of the body. A treatment team uses scans and planning software to shape the beam and set its direction. The machine may rotate around you, but it does not touch your body. Immobilisation supports or a mould may help you keep the same position each time.

Radiation treatment is planned around the tumour's location and nearby healthy organs. You remain awake, and staff can see and hear you during the session. The machine is checked and calibrated by specialist staff before it is used for patients.

Before treatment, attend the planning appointment and tell the team about medicines, implanted devices, pregnancy possibility, and difficulty lying flat. Wear comfortable clothing and follow any instructions about eating, drinking, or skin products. During treatment, keep the requested position and report discomfort rather than moving to adjust yourself.

A session includes positioning, imaging or verification, and delivery of the planned beam. The radiation delivery itself may be brief, while the full visit takes longer because accurate setup matters. You are not radioactive after external-beam treatment, so normal contact with family is generally possible unless your team gives different advice.

Contact your radiotherapy team promptly about new or worsening pain, marked skin reaction, repeated vomiting, inability to drink, fever, unusual bleeding, or symptoms that interfere with eating, breathing, sleep, or daily activity. Seek urgent medical help for severe breathing difficulty, confusion, fainting, or uncontrolled bleeding.

Ask which body area will be treated, how positioning will be checked, what side effects fit the treated area, and who to call outside appointment hours. You can also ask whether an implanted device changes the plan and how missed sessions are handled.