Focal Therapy in Prostate Cancer

​The natural course of prostate cancer is very variable. Aggressive prostate cancers usually require radical treatment (total removal of the prostate OR radiation of the entire prostate), which has been shown to be associated with a clear overall survival benefit. However, despite radical treatments being very effective, they can be associated with side effects. These are mainly incontinence and impotence.

On the other hand PSA screening for prostate cancer often leads to the detection of less aggressive cancers, which are unlikely to cause them any harm. These less aggressive cancers can be put under an active surveillance protocol, without the need for immediate radical treatment. In an active surveillance protocol patients are monitored closely with serial PSA checks and repeat prostate biopsy. The stringent monitoring informs the clinician if the cancer has changed its nature to a more aggressive form, at which point a radical treatment can be advocated. As a result unnecessary side effects are avoided in these patients. Some patients may however perceive this as the clinician "doing nothing" despite the diagnosis of cancer, which may cause them significant psychological distress. Furthermore there is no accurate way to assess the "true" aggressiveness of the cancer by means of physical investigation and biopsy only. As a result a significant proportion of patients opt for immediate radical treatment.

Focal therapy is a relatively novel treatment option, which closes the gap between active surveillance and overtreatment with radical therapy in early stage prostate cancer.

​In focal therapy, treatment is concentrated only on the tumor bearing regions of the prostate as opposed to the entire prostate in radical treatment. With this approach the adverse side effect profile is expected to be low. The therapeutic philosophy in focal therapy is similar to organ-preserving treatment options in breast and kidney cancers. In these cancers, tumor resection without removal of the entire organ is possible in a significant proportion of the cases. A growing number of scientific publications have demonstrated, that organ-preservation is also possible in selected patients with early stage prostate cancer. With mid-term follow-up, side effects have been shown to be extremely low.

For successful focal treatment not only modern imaging technology (MRI of the prostate) but also innovative treatment technology is required. Such an innovative tool is Focal One^®.

​High-intensity focussed ultrasound (HIFU) is a minimally invasive technology, that allows targeted local treatment of prostate tissue with a short hospital stay. With previous devices around 30,000 treatments (mostly of the entire prostate) have been performed worldwide. Focal One is a high tech device and the most modern development of High-intensity focussed ultrasound (HIFU).

A special feature of Focal One is the option to fuse MRI images of the prostate with the ultrasound of the prostate during treatment. This is why MRI is performed prior to treatment. If tumor is visible and confirmed by biopsy, tumor areas on MRI can be rendered and uploaded to Focal One. These pictures can be integrated with the real-time ultrasound image of the prostate (elastic fusion). This fusion of images enables accurate planning of the treatment zones. The treatment probe of Focal One generates high- intensified ultrasound waves (HIFU). Up to eight focus points generate lesions with a height of only 5mm. In comparison with previous devices this enables more precise treatment planning.

​The treatment can either be performed under spinal or general anaesthesia. Depending on the size of the treatment area, procedure time ranges between 30 minutes and 2 hours. The patient will have a bladder catheter inserted. During treatment the patient will be positioned on his right side with the legs flexed. The treatment probe will be inserted into the rectums and the treatment area planned as described. The targeted ultrasound waves have two effects: heat and mechanical damage of prostate cells.

Both effects lead to immediate tissue damage within sharply defined areas. At the end of the procedure immediate treatment control is performed by means of contrast-enhanced ultrasound. If necessary, local re-treatment can be performed immediately.

The bladder catheter will be removed after 2 days. The expected hospital stay is 3 days.

Focal therapy is relatively new technique. It is not considered treatment standard by international urologic guidelines. Therefore focal therapy should be performed within well-designed trials.

Successful focal treatment requires an extended diagnostic workup. In most of the cases prostate cancer occurs in many spots within the prostate (multifocal tumor). It is evident from from numerous studies that a standard 10 of 12-fold random biopsy of the prostate is not sufficient to locate the tumor safely within the prostate. Multiparametric magnetic resonance tomography (mpMRI) of the prostate is probably the best way to localise aggressive cancer. By means of MRI guided biopsy or MRI/ultrasound fused biopsy it is possible to biopsy MRI suspicious lesions under local anaesthesia. We have close cooperation with the department of radiology at our university hospital. With the results of all reports we will decide with our patients if focal therapy is reasonable.

​There is no consensus from guidelines which patients are suitable for focal therapy. Mostly it is recommended for patients with a life expectancy of >10 years, with organ-confined prostate cancer (Stage cT1c and cT2) without any evidence of metastasis. Depending on the study protocol PSA should not exceed 10 to 15ng / ml. Cancer should only be found in a limited number of biopsy cores (not more than 3), with a Gleason-Score not exceeding 3+4=7. During evaluation several other patient parameters are evaluated.

​Regular follow-up visits are important in order to assess the result of focal therapy: beside regular PSA-controls and physical examination a control MRI (after 6 to 12 months) as well as a control biopsy of the prostate after 12 months are necessary. Quality of life as well as potential side effects will be assessed by validated questionnaires.

​Toni Franz, MD

University of Leipzig Medical Center
Liebigstraße 20
D-04103 Leipzig
Germany

Phone: +49 (0)341 97 17608
Fax:    +49 (0)341 97 17609
Mail: Toni.Franz@medizin.uni-leipzig.de