Clinical trials

PROSEVEN: MR-guided prostate stereotactic body radiotherapy in seven days

Research goals

The use of stereotactic body radiotherapy (SBRT) is an established treatment for low and intermediate risk prostate cancer. SBRT allows the delivery of high doses per fraction to the prostate gland by using the combination of highly conformal radiotherapy and daily image-guided radiotherapy.  These techniques are possible using MR-guided radiotherapy.

A dose of 40Gy is 5 fractions to the prostate and 36.25Gy to the planning target volume (PTV) is increasingly regarded as the standard dose fractionation in prostate SBRT. Most of the trials using the 5 fraction schedule employed a weekly or every other day schedule. The impact of overall treatment time on disease outcomes, toxicity and effect on quality of life still needs to be elucidated. Recent data furthermore point to a possible benefit of a focal boost to the dominant intraprostatic lesion.

The Proseven-study is a prospective registration study enrolling patients with low-risk to limited high-risk localized and locally advanced prostate cancer. Large prostate volume, severe urinary symptoms as reflected by the International Prostate Sympton Score, contra-indications to MR-guided radiotherapy and hip protheses are important parameters used as exclusion criteria.

Patients will receive MR-guided stereotactic body radiotherapy in 5 daily fractions over 7 days.

A simultaneous integrated boost will be delivered to the dominant intraprostatic lesion.

The primary endpoint is physician reported acute gastrointestinal and genitourinary toxicity.

Secondary endpoints include physician reported late toxicity, patient reported outcomes and quality of life assessment and treatment efficacy parameters (freedom from biochemical failure, disease-free survival, overall survival). Patients will undergo routine oncological follow-up, the only additional investigation will be completing structured questionnaires (International Prostate Symptom Score, EORTC Quality of Life Questionnaire C30, Quality of Life Questionnaire PR252 and Expanded Prostate Index Composite-26) at defined intervals.

In total 120 patients will be enrolled to examine the feasability of MR-guided stereotactic radiotherapy to the prostate using an overall treatment time of 7 days.



Researchers: Dr. Jacques Bezuidenhout, Prof. Benedikt Engels, Prof. Mark De Ridder, Prof. Guy Soete, Dr. Bernard Rappe, Dr Christine Collen

Data manager: Ka Lun Law

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Response prediction of rectal cancer to chemoradiotherapy: a retrospective observational study using a random subspace decision forest analysis.

Research goals

Preoperative (chemo)radiotherapy is the standard of care in locally advanced rectal cancer and results in an excellent local tumor control. However, the respons to preoperative chemoradiotherapy is heterogeneous and remains unpredictable. Patients with a complete clinical remission (CCR) may profit from a watchful-waiting approach.

The MRIdian is a novel radiation platform that integrates a 0,35 Tesla MRI-scan for daily imaging on the treatment couch and adaptive radiotherapy. Its high precision will allow dose escalation on rectal tumors to increase the CCR rate.

The aim of the study is to build a statistical model based on retrospective data of rectal cancer patients treated at UZ Brussel. This model will be used to predict the response of rectal cancer to pre-operative radiotherapy and chemo-radiotherapy. The results of this study can be used as a basis for patient-specific dose prescription on the MRIdian in the near future.


Coordinator: Prof. Mark De Ridder

Researchers: Prof. Mark De Ridder, Prof. Kurt Barbé, Prof. Johan de Mey, Dr. Sandra Sermeus, Camille Raets, Chaimae El Aisati

Data manager: Ka Lun Law

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EORTC-1414-ROG-GUC trial

Research goals

Phase III trial examining the use of two different types of androgen deprivation therapy in patients with prostate cancer necessitating a combined treatment with radiotherapy and long term androgen deprivation therapy.  Patients from different categories are eligible for inclusion: high-risk localised prostate cancer,  locally advanced prostate cancer,  salvage radiotherapy after prostatectomy and oligometastatic prostate cancer with radiation of the prostate.

The growth of prostate cancer is largely driven by androgens, including testosterone.  Androgen deprivation therapy blocks the production of testosterone, hereby inhibiting prostate cancer growth. It has been shown that the efficay of radiotherapy for prostate cancer is enhanced with the addition of androgen deprivation therapy. 

In this trial two types of androgen deprivation therapy will be used: LHRH-agonists (Luteinizing Hormone Releasing Hormone) (leuproreline, gosereline, triptoreline) and LHRH-antagonists (degarelix).

LHRH-agonists have been used for more than 30 years and is regarded as the standard of care. In first instance they cause a surge in testosterone which necessitates the addition of antiandrogens during the first weeks of treatment. LHRH-agonists are injected subcutaneously or intramuscularly every 3 or 6 months.

LHRH-agonists don’t lead to an initial surge in testosterone. Preliminary data suggest that LHRH-antagonists might have a longer duration of action and might have fewer side effects. These products are injected subcutaneously monthly.

The androgen deprivation therapy will be given before, during and after the radiotherapy, except in the case of salvage radiotherapy after prostatectomy where both treatment will start on the same day. The total duration of androgen deprivation therapy will be 6 months (in the case of salvage radiotherapy), 18, 24 or 36 months depending on the decision of the treating physician.

Follow-up will be performed at specified intervals during the treatment and after the completion of the treatment. The follow-up will include questionnaires regarding quality of life. Performance status, weight and blood pressire will be assessed. Laboratory tests will include PSA (prostate specific antigen) and testosterone. An electocardiogram will be performed 3 months after start of the treatment.

The study also includes a translational component with the option of salivary collection for genetic testing (examining genetic changes caused by the use of androgen deprivation therapy and possible linkages to side-effects of the treatment).

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