Accurate prostate diagnostics thanks to multimodal imaging
Prostate MRI is the currently best imaging method for depicting the prostate in order to rule out or detect a tumour. MRI enables greater diagnostic accuracy thanks to multimodal imaging: perfusion, diffusion imaging and MR spectroscopy, if necessary, provide exact information about the location and spread of a possible tumour in a non-invasive procedure.
With 50,000 new cases annually, prostate cancer is the most frequent malignant tumour in men. The cause of its development is, as for many other cancer diseases, largely unknown. However, genetic factors, a high-fat diet, environmental factors as well as hormone influences are probably the cause. Thus the risk of disease is approximately 4 to 5 times higher if one’s father or brothers have prostate cancer.
Recent studies, for example published in the renown "The New England Journal of Medicine" (external link to the article), show that the diagnostic accuracy of the MRI of the prostate is superior compared with the traditional diagnostic path of the evaluation of PSA level, digital examination and random biopsy.
Palpation of the prostate recommended from the age of 50 is unfortunately not very reliable. Particularly small tumours are hard to detect with this method. Transrectal sonography is also conclusive only to a limited extent. Therefore, urologists determine the so-called PSA value (prostate-specific antigen) in addition. If it exceeds 4.0 ng/ml, there is suspicion of a tumour, and a tissue sample (biopsy) of the prostate should be taken. The reason: About 30% of 50-year-old men and up to 70% of over 80-year-olds have asymptomatic prostate cancer – often hidden amongst benign tumours.
However, the PSA value is high in over half of the cases with benign and harmless prostate diseases. Usually random biopsy (up to 18 samples) achieves a hit rate of only 30 to 40%. Thus this procedure is far from ideal.
If no tumour cells are found in a biopsy, that still does not rule out a tumour by any means. Then the biopsy has to be repeated if necessary. If a tumour is detected, it often remains unclear how extensive or aggressive it is.
For diagnosis of prostate cancer, magnetic resonance imaging is clearly superior to other imaging procedures. Thanks to the possibility of functional MRI diagnostics, it is currently the best imaging method for depicting the prostate and provides important information about the exact location and spread of a tumour as well as its aggressiveness in a non-invasive procedure. MRI can help to prevent possibly unnecessary diagnostic and therapeutic interventions for less aggressive tumours or benign changes.
Suspicious areas can be identified by MRI before a planned biopsy (tissue removal) significantly increasing the probability of finding the tumour. If a biopsy is necessary, the image data obtained during the MRI examination can be transferred directly to the urologist’s ultrasound images and thus mark the (sonographically usually invisible) tumour for the biopsy (so-called MRI fusion biopsy).
Suspicious areas in the prostate have to be biopsied to enable accurate classification and to confirm the diagnosis. MRI fusion biopsy is a novel procedure which enables the detection of particularly small and inconveniently situated tumour lesions with considerably higher accuracy (up to 85%) by combining the MRI scan with sonography during the biopsy.
If a tumour is detected (incl. in the biopsy), MRI can provide valuable information for planning treatment, for example, whether surgery or radiation is more appropriate or whether it is possible to wait and see (a technique known as ‘active surveillance’). For not every tumour grows aggressively.
Safety and certainty for patients can be significantly improved with prostate MRI since aggressive tumour growth can already be detected at an early stage.
Since magnetic resonance imaging does not require any X-rays, it is also perfectly suited to further monitoring in the case of unclear findings.
MRI is also instrumental in finding a so-called local recurrence (renewed PSA increase after therapy).
Conversely, aggressive tumour growth is relatively improbable if prostate MRI does not reveal any tumours.
1. High-resolution imaging
High-resolution MRI pictures of the prostate and its surroundings show the exact anatomy as well as suspicious areas (arrow: small prostate carcinoma).
2. Diffusion-weighted imaging (DWI)
Another innovation of prostate imaging that we offer at our surgery is so-called diffusion imaging, in which the diffusion (motion) of water molecules is examined and displayed graphically. Particularly aggressive prostate cancer can be detected more easily this way since water diffusion is limited by the increased cell density in the tumour.
3. Perfusion imaging (dynamic MRI)
During a perfusion examination, the contrast uptake in the prostate is examined over time as an indicator of blood circulation. Since tumours need nutrients for growth, they are usually supplied increasingly with blood, which distinguishes them from normal prostate tissue.
4. MR spectroscopy (MRS)
Additional accuracy thanks to high field MRI spectroscopy (MRS) of the prostate
With this special procedure, a tumour can be directly detected by suspicious metabolic products. In prostate cancer, citrate levels typical of normal prostate tissue are low and choline levels are high. During the examination, the prostate is systematically scanned for such suspicious areas.
The magnetic resonance scanner creates high-resolution images of the prostate and also precisely depicts surrounding structures such as the seminal vesicles and the pelvic floor. In conventional MRI systems with a field strength of maximally 1.5T, it is usually necessary to insert an endorectal coil for this purpose. An unpleasant procedure which we spare our patients by using a state-of-the-art 3T high field MRI scanner with multi-transmit technology.
The entire examination is performed without a coil while you are lying down comfortably and takes approx. 25 minutes.
To visualise the blood circulation of the prostate as well as lymph nodes and to enable better differentiation of other structures, a well tolerated contrast agent (gadolinium) is administered intravenously in an arm. Please inform us, if you have a relevant allergy or any kidney dysfunction. During the examination, the urinary bladder should be as empty as possible.
Since prostate MRI reacts very sensitively to motions, well tolerated medication which suppresses bowel movement is administered before the examination (Buscopan). However, you should drink as little as possible and avoid tea and coffee before the examination. Gassy foods (e.g. beans) must be avoided on the day before the examination.
Important: an MRI examination of the prostate should not be performed during the first 6 weeks after a prostate biopsy.
Private health insurance providers in Germany usually reimburse the full screening examination costs. Patients insured under state/government insurance plans in Germany can have prostate MRI performed as a self-payer service. Unfortunately, cost coverage is currently not provided for this elaborate examination by compulsory health insurance funds.
Benefit from our experience: we also offer a second diagnosis or second opinion on request.
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