Linear Accelerator in Cancer Treatment

A linear accelerator delivers carefully shaped high-energy radiation to a treatment area while helping limit exposure to nearby healthy tissue.

Before treatment, imaging and planning define the target and the position you should use. At each visit, therapists align you with marks or image guidance, then leave the room while the LINAC operates. You can speak with the team through an intercom. The beam is on only during planned delivery, while the setup may take longer than the radiation itself.

A LINAC treats a defined area rather than the whole body at once. Movement from breathing, difficulty holding still, or changes in anatomy can affect planning and positioning. Radiation effects depend on the body area and the treatment plan, so fatigue, skin changes, or other effects may occur during or after a course. The machine is one part of care; it does not decide the dose or target by itself.

The same type of machine can support different planning approaches. External beam radiotherapy describes treatment delivered from outside the body. Intensity-modulated radiotherapy varies beam intensity to shape dose. Stereotactic body radiotherapy uses highly focused treatment for selected targets. Your radiation oncologist chooses an approach based on the tumour, nearby organs, and overall plan.

You may have imaging before planning and short appointments for each treatment session. A LINAC treatment does not make you radioactive. Wear comfortable clothing, follow positioning instructions, and tell the team about pain or difficulty staying in position. Ask which skin or activity changes are expected for your treatment area and when to report them.

The team checks your identity, treatment area, positioning, and plan before delivery. You are alone in the room during beam delivery because staff monitor you from nearby, but they can see and hear you. Tell the team if you might be pregnant, have an implanted device, or cannot lie comfortably.