First radiation

Your first radiotherapy session usually follows two to three weeks after the CT-simulation. This time span is needed to set up and thoroughly check your treatment plan.


  • You will be collected in the waiting room after reporting to the secretariat.
  • Before the radiotherapy starts, the nurses will carefully install you on the table.
  • Once you have been installed correctly, the nurses go to the adjacent operating room, from where they can observe you on a television screen and hear you through an intercom system.
  • The table may make a small movement before the real radiation starts. This way, the position of the CT-simulation is reproduced perfectly.
  • It is very important not to move during the radiation until the session is complete. Depending on your treatment plan, the proton therapy device and/or the table will change positions several times. You will not feel the radiation itself. The device, however, may make a sharp humming noise during irradiation. When the irradiation session is over, the nurses will ask you to come down from the table. The duration of irradiation is calculated individually for each patient.

For safety reasons, family and friends cannot legally enter the radiation area.

Further radiation sessions

The radiotherapist-oncologist decides how your treatment will proceed. Even for the same condition, treatment may differ from patient to patient.

The total number of radiation sessions, the total dose and the time needed between radiation sessions are determined by the type of tumour, the location of the tumour in the body and the results of medical examinations.

The total number of sessions may vary from 20 to 37. During weekends and holidays, you will usually not be radiated, unless the radiation device was in maintenance for several days during the previous week.

Part of your treatment may also be administered with photon radiation: if the treatment protocol prescribes so or in case of maintenance/defect of the proton therapy device, so that no time is lost in the fight against the tumour. Your doctor will discuss this with you.



  • For all your practical or medical questions regarding your proton therapy treatment, you can always contact your treating radiotherapist-oncologist or one of the nurses of the proton therapy team.

    For practical or administrative matters you can also contact the secretariat of the radiotherapy department. (The staff at the reception desk in the shared proton therapy and radiology waiting room are not familiar with it). Secretariat staff can be reached by phone on 016 34 76 00 or by e-mail at

Last edit: 16 February 2023