Halcyon linear accelerator

Before treatment, the team uses planning scans to map the target and nearby organs. You are positioned in the same way for each visit, often with supportive equipment that helps you remain still. The machine rotates around the couch and delivers radiation from planned angles; it does not touch you and the beam cannot be felt. Imaging may be used to check position before delivery. The technology is one part of a treatment plan, alongside the prescribed dose, schedule and safety checks.

Follow the instructions about clothing, skin products, bladder or bowel preparation, and whether to eat or drink beforehand. Wear comfortable clothing and tell the team if lying flat is difficult or if you feel anxious in the treatment room. During treatment, remain still and use the communication system if you need help. Your team can explain [Radiotherapy](/treatments/radiation-oncology/radiotherapy/) and whether a more focused approach such as [Stereotactic Body Radiotherapy](/treatments/radiation-oncology/stereotactic-body-radiotherapy/) suits your plan.

Report new or worsening pain, skin breakdown, persistent vomiting, severe tiredness, or symptoms affecting the treated body area. Seek urgent help for sudden weakness, confusion, chest pain, severe breathlessness or a seizure. Do not wait for the next appointment if symptoms are severe or rapidly worsening.

Ask why this machine is recommended, how positioning will be checked, how long each visit may take, what side effects match the treated area, and whom to call outside clinic hours. Ask whether your plan includes image guidance or motion management.