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Planning radiotherapy

Find out what happens at your planning appointment for external radiotherapy.

Planning your treatment

The radiotherapy team plans your external beam radiotherapy before you start treatment. This means working out how much radiation you need to treat the cancer and exactly where you need it. Your planning appointment takes from 15 minutes to 2 hours.

You have a planning CT scan in the radiotherapy department. The scan shows the cancer and the area around it. You might also have other types of scans or x-rays so that your treatment team can plan your radiotherapy.

Photo of a CT scanner

Ink and tattoo marks

The radiographers might make pin point sized tattoo marks in the treatment area. These make sure they treat exactly the same area every day. They may also draw marks around the tattoos with a permanent ink pen. This highlights the tattoos and makes them look like small crosses.

Radiotherapy tattoo marks
Radiotherapy treatment area marks.

The radiotherapy unit staff tell you how to look after the markings. The pen marks might start to rub off in time. If that happens, tell your radiographer. Don't try to redraw them yourself. 

After your planning session

It can take a few days or up to 3 weeks before you start treatment.

During this time your radiographers and doctors create your radiotherapy plan. They make sure that the area of the cancer will receive a high dose and surrounding areas receive a low dose. This reduces the side effects you might get during and after treatment. 

Last reviewed: 
06 Apr 2016
  • Penile carcinoma: ESMO clinical practice guidelines

    H. Van Poppel, N. A. Watkin, S. Osanto, L. Moonen, A. Horwich, V. Kataja

    Annals of Oncology 2013; 24 (Suppl 6): vi115-vi124

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