Inaugural lecture: 'Off the beaten track for better individual radiotherapy'

2 September 2021• PRESSRELEASE

About fifty different types of sarcoma are known, and all of them are treated with the same dose of radiotherapy. According to Rick Haas, Professor of Radiotherapy, in particular of bone and soft tissue tumors, this should be improved. In his inaugural lecture, 'Dosed deviations and deviating doses', which he will deliver on 3 September, Haas will emphasise the importance of research into adapting the standard dose of radiation for sarcoma patients.  

Radiotherapist Rick Haas has spent his entire scientific career exploring ways to optimise radiotherapy of tumors. This means that the radiation kills tumor cells and at the same time causes as little damage to the body as possible. "During my training, I was already astonished by the fact that a patient with a soft tissue tumor, also known as sarcoma, is treated with 25 sessions of radiation, regardless of the characteristics of the patient and the tumor. I just couldn't imagine that this was right."

Less radiation, more effect

This astonishment was the basis for a study into a lower radiation dose for patients with a certain subtype of sarcoma, so-called myxoid liposarcoma. In this study, in which LUMC also took part, patients received 18 instead of 25 radiations. "We managed to keep the sarcoma completely under control, and the short- and long-term side effects were reduced by half." This gave Haas even more reasons to investigate different doses for other sarcoma types. 

Impact on quality of life 

Reducing or preventing side effects is an important outcome measure of Haas' research. According to him, these can be very harmful. "In the long term, radiotherapy can lead to scarring and stiffening of joints. Because sarcoma frequently occur in the arms and legs, this can have a huge impact on patients' quality of life. We also see that the surgical incision after removal of the tumor heals more slowly if 25 sessions of radiation have been given. But the good news is that if we reduce the number of radiations from 25 to 18, this effect is already eliminated." 

Promising results

In addition to the effect of lower doses, Haas also wants to look at the combination of radiation and chemotherapy in the coming years. "This requires a multidisciplinary approach," says Haas, who works as a radiotherapist at both the Antoni van Leeuwenhoek and the LUMC. "I actually fulfil a bridge function between the two hospitals so that we can initiate studies of this kind together." The rare nature of sarcomas underlines the importance of this kind of collaboration. "Sarcomas are diagnosed about 800 times a year," says Haas. "In order to recruit enough patients for research, we have to work together." 

Daring to deviate

Many different medical specialists are involved in the treatment of sarcomas. " Collaboration between surgeons, radiotherapists, internists, pathologists and radiologists is essential in the treatment of sarcomas. The expertise of the last two in particular is indispensable for our research. I value this collaboration and their input enormously."

Despite the fact that the results of Haas' research are promising, the 25 sessions of radiation are still the standard for treating all sarcomas. "I am confident that we will obtain enough scientific evidence to tweak not only the total dose, but also the radiation dose per day. With this, we hope to change the future guidelines, and thereby sarcoma care, for good."

The inaugural lecture of Rick Haas on September 3 at 16:15 can be followed via a livestream.

Stay informed on the latest news of the Leiden University Medical Center, and sign up for our biweekly newsletter or subscribe to our LUMC Magazine.