Prostate cancer

External beam radiotherapy (EBRT) is commonly used as single modality in most radiotherapy departments. It uses a linear accelerator to deliver radiation from outside the body.

External beam radiotherapy as single modality might be the best option for patients with a prior transurethral resection of the prostate, more favourable cancers, larger prostates or increased urinary problems at presentation. External beam radiotherapy is applied as a so called volumetric modulated arc therapy (VMAT), delivering the dose during continuous rotation of linear accelerator gantry around the patient and continuous movement of the leafes that are forming the beam from the respective direction.

Image-guided radiotherapy

It is essential for precise targeting.

An optimal patient preparation before radiotherapy and precise organ localization before each treatment is essential for an effective treatment, exactly delivering the dose to the cancer with best posible protection of the neighbouring healthy tissue.

Spacer application for rectum protection

As the prostate is in immediate neighbourhood to the rectal wall, the rectal wall is always included in the high dose volume in external beam radiotherapy. The consequence is a higher risk of rectal complications, as rectal bleeding or ulcerations, and a significantly decreased bowel quality of life after radiotherapy.

At WEGE Klinik, a hydrogel spacer (SpaceOAR) is injected between the prostate and rectal wall transperineally under transrectal ultrasound imaging, ensuring a 1cm distance between the prostate and rectal wall. The hydrogel spacer remains stable for 3 months and consecutively resolves without any additional interventions.

Prof. Pinkawa was an investigator in the first clinical study with the hydrogel spacer and performed the first injection worldwide in clinical routine in 2010, thus having the longest worldwide experience for this procedure. In the last 15 years, many studies have been published, including a large randomized study, reporting a significant bowel quality of life advantage for radiotherapy after spacer placement in comparison to conventional radiotherapy without a spacer. Bowel quality of life remains the same as bowel quality of life before treatment in patients treated with a hydrogel spacer. More detailed analyses also report improved sexual quality of life in comparison to conventional radiotherapy, thus a higher probability of erections sufficient for sexual intercourse.

For an optimal visualization of the anatomy with the hydrogel spacer, a computed tomography amd magnetic resonance imaging are performed for treatment planning at WEGE. Fusion of both imaging methods in the planning improves the definition of the prostate and the spacer in comparison to conventional treatment planning that is based only on computed tomography.

Brachytherapy is based on placement of radioactive sources directly into the prostate, either permanently (LDR brachytherapy, low-dose-rate, applying Iodine-125-sources) or temporarily (HDR brachytherapy, high-dose-rate, applying an Iridium-192-source).

The consectutive advantage is a high biological dose in the tumour without penetration of the skin and other neighbouring organs, thus high dose conformality with a steep dose decline around the prostate.

Brachytherapy can be used as single modality for low risk or favourable intermediate risk patients, usually as LDR brachytherapy. This includes a single procedure of about 1 hour duration and an overnight stay in WEGE. In patients with specific risk factors, reduced dose/duration external beam radiotherapy is combines with brachytherapy as a boost, usually applied in two fractions as HDR brachytherapy.

Clinical studies show that this combined approach improves tumor control, reduces metastasis risk, and may improve survival compared to EBRT or surgery alone.

Prof. Pinkawa, who introduced this method into clinical practice in 2010, has the longest experience worldwide with the spacer. Clinical studies confirm that it significantly reduces bowel side effects and improves quality of life—both gastrointestinal and, in many cases, sexual. Planning with both CT and MRI ensures precise definition of the prostate and spacer, improving the safety and accuracy of treatment.

Image-guided radiotherapy

An optimal patient preparation before radiotherapy and precise organ localization before each treatment is essential for an effective treatment, exactly delivering the dose to the cancer with best posible protection of the neighbouring healthy tissue.

During the brachytherapy procedure, the applicator needles are placed during continuous visualization of the prostate with a transrectal unltrasound. For external beam radiotherapy, external imaging methods need to be used every day to localize the prostate.

Commonly, three gold fiducials are implanted transperineally with a transrectal ultrasound guidance into the prostate before treatment planning imaging for external beam radiotherapy. With the ExacTrac Dynamic system (Brainlab), these fiducials are localized at the treatment table with a dedicated x-ray system that identifies these fiducials and adapts the position of the treatment table in all six directions (including tilting in all directions). Even applying a cone beam computed tomography at the linear accelerator, these fiducials increase the positioning precision significantly.