Further local therapy of prostate cancer

Further local therapy of prostate cancer

Even with the still experimental procedures, such as cryotherapy, HIFU (Ultrasound) and hyperthermia can prostate cancer be handled locally. They are considered minimally invasive, but are still subject of research.

For years new, minimally invasive (little intrusive) methods for local (local) treatment of prostate cancer are being developed, such as cryotherapy, HIFU therapy and hyperthermia (see below).Ideally, they should be equally good results less risks and side effects than the previous standard methods, the radical prostatectomy and radiation therapy . Whether this is actually true, but needs still to come, so that their application is currently recommended only in the context of studies. While there are already numerous studies, most of cryotherapy, but their significance is limited, partly because long-term results and the direct comparison with the above-mentioned conventional methods are still pending.

Cryotherapy

Under cryotherapy (better: cryosurgery) is defined as an intervention to the destruction of tissue using extreme cold (from the Greek kryos = Frost): ice crystals puncture cell membranes, dehydration clumped proteins, chemical changes lead to programmed cell death (apoptosis), and degradation of blood vessels interrupts the supply to the tissues with oxygen and nutrients.

The modern cryoablation of the prostate (ablation = ablation, English: cryosurgical ablation of the prostate = CSAP) is usually carried out during a short hospital stay in "spinal anesthesia" or general anesthesia: Under TRUS control ( TRUS = transrectal ultrasound) are transperineal (by the dam ) introduced several needles into the prostate and their environment: "cold needles" for freezing and thawing, and "heat needles" for the protection of the rectum (rectal); probes measure the temperature and a heating catheter protects the urethra. The prostate is then thawed twice frozen (at -40 ° C in the center and at the neurovascular bundle) and back.

After the procedure, swells the damaged tissue. That is why for a few days, a bladder catheter needed later can also be a surgical ablation of prostate tissue ( TURP ) are required. The neurovascular bundle, which bear the prostate rear-side and for the erection (stiffening member) contain important nerves can be preserved only in exceptional cases. So it happens in most patients to erectile dysfunction (ED, disturbance of the stiffening member). Other side effects are rare.
After the German guideline cryotherapy is not an appropriate alternative to the standard procedure for initial treatment of localized prostate cancer, because there are no trial data to justify it. The method should also not be used in the treatment of locally advanced prostate cancer. Because there is evidence both for their effectiveness as well as their inferiority, the data for a treatment recommendation is not sufficient.

After the (weaker) European guideline cryoablation (CSAP) can be considered in patients with localized or only slightly above the capsule spread prostate cancer without metastases, especially if they can not be operated on and have a life expectancy of less than 10 years.Possible candidates are patients with low or moderate risk of progression of the tumor (c T1-2 N0 M0, Gleason score to 7, PSA level to 20ng/ml). Prostate volume should be up to 40ml (possibly after reduction by pretreatment using hormone therapy). Patients should be informed that long-term results are lacking and the results after 5 years are worse in patients with low risk than after radical prostatectomy. Another field of application is the relapse (recurrence) of the tumor after radiotherapy for patients who can not have surgery (see also the section "radiotherapy" among relapsed ). This is called (in English: salvage = rescue) from a salvage cryotherapy.

HIFU therapy

The abbreviation stands for high intensity (high-energy) focused (collimated) ultrasound (English: high intensity focused ultrasound). When treated with HIFU ultrasonic waves are generated as bundled with a magnifying glass in the target area. The tissue absorbs the energy there and perish, especially by heating to about 65 ° C. Which is located between the sound source and the target and the surrounding tissue are however hardly loaded.

For HIFU treatment of prostate cancer, a short hospital stay and a "spinal anesthesia" or general anesthesia are usually necessary: ​​the ultrasonic source is inserted rectally (into the rectum) and to cover the entire target area with numerous individual effects automatically moved, which, depending on prostate size usually lasts 2-4 hours.

Compared to cryotherapy the damaged tissue for a long time after the procedure swells, so that the urinary catheter must be left longer. A subsequent ablation of prostate tissue ( TURP ) is more often necessary and, therefore, usually earlier or performed at the same time. In addition, it is more common for urinary incontinence , but slightly less often for erectile dysfunction (ED, disturbance of the stiffening member). Other side effects are also rare, a nerve sparing is more feasible.

After the German guideline, the HIFU therapy in localized prostate cancer is an experimental procedure and should only be used in studies. It is not intended to be used in the treatment of locally advanced prostate cancer. In both cases, the data for a treatment recommendation is not enough. This method, however, can be used in a means of prostate biopsy secured relapse (recurrence) of the tumor by percutaneous radiotherapy (external radiation) without metastases (as so-called salvage therapy HIFU). The patient should be previously informed about the experimental nature of this treatment and the other treatment options (see also the section "radiotherapy" among relapsed ). The European guideline assesses the HIFU therapy basically the same.

Hyperthermia

As hyperthermia (overheating) is called an increase in body temperature of intact thermoregulation in the brain (as opposed to fever). It can be for treatment purposes and artificially bring from the outside (eg by mats with warm water). , The prostate is heated to more than 42 ° C, it enhances the effect of a previous or subsequent exposure. Such hyperthermia has only been used in some studies for locally advanced prostate cancer, so there is correspondingly little information on results and side effects.
After the German guideline hyperthermia is an experimental procedure, because their value due to lack of studies, particularly comparative studies can not yet be reliably assessed. They are therefore to be applied either alone or as an initial treatment of localized prostate cancer for treatment of locally advanced prostate cancer.

Focal therapy

Currently, many other methods for the treatment of localized prostate cancer are currently being tested, for example, the RFA and the PST (see below) and the use of electricity (electrosurgery) and microwaves (such as transurethral microwave thermotherapy = TUMT ).All are still considered experimental, and have a focal therapy to the target, ie, the targeted disruption of a single hearth cancer while sparing the rest of the prostate (and the erection nerves). The latter is possible with cryotherapy and the HIFU treatment. Greatest difficulty is with reasonable certainty to determine location and extent of the hearth and to exclude the presence of another hearth.

In the RFA (radiofrequency ablation) of the tumor (English: radiofrequency interstitial tumor ablation = RITA), the ablation (ablation) by heating the tissue using radio frequency waves (radio waves) via needle electrodes are inserted into the prostate. This method is also used for transurethral needle ablation ( TUNA used) for the treatment of benign prostatic hyperplasia.

PDT (photodynamic therapy) will also been successfully used in other diseases. Here, we injected a substance into a vein or directly into the prostate. This accumulates in the tumor and damage to these as soon as it is activated with light of a suitable wavelength over an inserted into the prostate laser fiber. Such a substance is called photosensitizer, because it makes the cells sensitive to light.