“New Radiation Technique – Extreme Hypofractionation for Prostate Cancer Treatment in Netherlands”

For the new radiation technique, called extreme hypofractionation, the ZRTI uses the TrueBeam radiation accelerator from Varian Medical Systems that is already present in the centers. In addition to the ZRTI, this method for irradiation of prostate cancer in the Netherlands is also used at the Verbeeten Institute, Maastro and Amsterdam UMC.

Recently, a number of lab technicians have been trained within the ZRTI to apply extreme hypofractionation. The new method has been in use since August 2022 deployed. The number of lab technicians for this will be further expanded in the coming period.

Radiation technique operation

Before the radiation can start, special gold markers are placed in the patient’s prostate. They help to locate the prostate during treatment. Triggered imaging is used for this. To do this, the imaging part of the accelerator takes a whole series of X-rays in a short time. Together with the placed gold markers, it can then be determined whether or not the prostate moves.

“The locations of the gold markers remain accurately visible during the entire irradiation. If an abnormality occurs, for example if an air bubble passes or a patient suddenly tenses, the accelerator uses the AutoBeam Hold function and the radiation is automatically paused. We can then reposition the patient where necessary and resume treatment. The special thing about this technique is that the radiation is administered extremely accurately, making it possible to deliver a daily dose per session that is two and a half times higher compared to regular radiation,” says Inge Jacobs, radiotherapist-oncologist at the ZRTI.

The innovative new radiation technique is now only available for patients with a low risk profile. For patients who have a higher risk of metastases, a different treatment is often chosen. This choice depends on the value of the Prostate Specific Antigen (PSA), the aggressiveness (Gleacon score) and the stage of the tumor.

Fewer treatments

The reduced burden on the patient is one of the great advantages of the new radiation technique. Regular radiation means that a patient must undergo between 20 and 38 treatments. With extreme hypofractionation, the new radiation technique, that number can be reduced to just five treatments.

In addition, the new radiation technique, which is much more accurate, also leads to a smaller chance of side effects. “After all, there is less risk that surrounding tissues or organs will be affected. Research indicates that extreme hypofractionation produces the same results as regular radiation. The chance of recovery therefore remains just as high,” says Tom Harthoorn, radiotherapy lab technician.

Also important is the fact that the new radiotherapy technique means that the accelerator is used for less time per patient. This not only means that the costs per treatment process are reduced, but also that more patients can be treated.

Further development and future

The development of this new radiation technique is of course not standing still. The ZRTI is currently installing the Ethos therapy from Varian Medical Systems. This allows the extreme hypofractionation treatment to be further optimized. Consider, for example, adjusting the treatment to the location and shape of the surrounding organs. This may mean that the treatment can also be used for other patients in the future.

“In theory, we can also irradiate other motile tumours, for example in the liver, breasts or lungs. It may even be possible to treat a patient with prostate cancer with even fewer fractions. That is still music in the future at the moment. We have only recently started this new treatment method. We will first delve deeper into this and gain experience with it,” says Inge Jacobs.