A LINAC is the machine used for external beam radiotherapy. It delivers controlled radiation to a defined area of disease, while treatment planning aims to reduce exposure to nearby normal structures.

Before starting, imaging and measurements are used to mark the treatment region. The patient lies still on the treatment couch while the unit moves around the body and releases radiation for a short duration. The session itself is painless, and patients can return to routine activity afterwards unless advised otherwise.

Treatment is usually given over multiple visits rather than a single sitting, so surrounding tissues have time to recover. The schedule depends on the cancer type and clinical stage.

Radiation oncologists review progress during the course of therapy and modify the plan if required.