Radiotherapy planning is the appointment used to design your treatment before the first dose is given. It is sometimes called simulation because the team rehearses your treatment position.
This step is not the treatment itself. It helps your radiation oncologist, physicists, and radiotherapy radiographers decide exactly where the radiation should go and what should be protected.
Common Indications for Radiotherapy Planning
You may need planning before:
- External beam radiotherapy.
- Breast, prostate, cervical, lung, brain, or head and neck radiotherapy.
- SBRT, SRS, IMRT, or VMAT treatment.
- Radiotherapy after surgery.
- Radiotherapy given with chemotherapy.
- Treatment to relieve pain or bleeding.
What exactly does planning show?
Planning shows the treatment team your body position, the target area, and nearby organs that need protection. It may use CT, MRI, PET-CT, previous scans, or surgical information.
How should I prepare?
Follow the instructions given by your centre. Some plans need a full bladder, an empty rectum, fasting, or a special mask or mould. If the instruction is unclear, ask before travelling.
Do I need to stop taking medication?
Usually no. Keep taking your regular medicine unless your doctor gives a specific instruction.
What happens when I arrive?
The team confirms your details and explains the position. They may use cushions, arm supports, a breast board, a head mask, or leg supports to help you stay still.
How is simulation performed?
You lie in the treatment position while a planning scan is done. The team may place small marks on your skin or on a mask. These marks help them line you up the same way during treatment.
Are the skin marks permanent?
Some marks are temporary ink. Some centres use tiny permanent tattoo dots. Ask your team which one they use, so you are not surprised.
How long does planning take?
Planning may take 30 minutes to over an hour. More complex treatment areas can take longer.
Is there any discomfort?
The planning scan is usually painless. The hard part is keeping still, especially if a mask feels tight or you have pain. Tell the team if you need a pause.
Are there risks?
CT and PET-CT planning scans use ionising radiation; MRI does not. Your team chooses the imaging needed to plan treatment accurately. If contrast dye is needed, they will ask about allergies, kidney problems, and other relevant conditions first.
Can I have planning if I am pregnant?
Pregnancy Precaution
Tell your doctor or radiographer if you are pregnant or think you might be. Some planning scans and radiotherapy use ionising radiation, so the team must know before they proceed.
When does treatment start after planning?
Treatment does not always start the same day. The team needs time to create and check the plan. Your centre will tell you when to return.
Sources and further reading
- National Cancer Institute: External Beam Radiation Therapy and treatment planning
- National Cancer Institute: Radiation Therapy to Treat Cancer
Conclusion
Planning is the quiet but important step that makes radiotherapy safer and more accurate. Bring your previous scans or reports if you have them, and ask exactly how to prepare before your planning day.