What should you know about linear accelerator equipment?

The machine is commonly called a linac. It produces high-energy radiation, directs it from a selected angle, and can move around you without touching your body. A treatment team uses imaging, planning software, and positioning supports to align the prescribed field with the target.

A linac has a treatment head that shapes and aims the radiation beam. The treatment couch supports your body, and imaging systems may check your position before or during delivery. The equipment does not make you radioactive, because the radiation is produced for the treatment and stops when the machine is switched off.

Before treatment begins, specialists create a plan using your scan and clinical information. They may use a mould, mask, or other support to help you keep the same position. The machine may make buzzing or clicking sounds, but the radiation itself cannot be seen or felt. You are normally alone in the room during delivery while staff watch and communicate with you from nearby.

Follow the instructions from your radiation team about eating, drinking, medicines, and skin care. Wear clothing that allows the treatment area to be reached comfortably, and tell staff if lying in one position is difficult. Mention implanted devices, mobility needs, pregnancy, or a possibility of pregnancy before planning or treatment.

During the appointment, ask for help before moving once you are positioned. Staying still helps the planned field remain aligned. Report new pain, anxiety, skin changes, trouble swallowing, or other symptoms so the team can decide whether you need supportive care or a plan adjustment.

Contact your oncology team promptly if you develop symptoms that are severe, rapidly worsening, or interfere with drinking, eating, breathing, movement, sleep, or daily activities. The right contact route may be a treatment-unit number, clinic team, or urgent-care service; confirm it before your first session.

Seek urgent medical help for severe breathing difficulty, new confusion, fainting, uncontrolled bleeding, or sudden weakness. These symptoms need assessment regardless of whether they occur on a treatment day. Do not wait for the next scheduled appointment when a symptom feels like an emergency.

Ask which part of the body the plan targets, how positioning will be checked, whether you will need a mask or mould, and what sensations or sounds to expect. You can also ask how long each visit may take, who to call about side effects, and whether another radiation technique is suitable for your situation.