Study in prostate cancer
After anamnesis and clinical examination followed by digital examination, PSA testing and ultrasound. They only allow a suspicion of prostate cancer, so that the diagnosis must be secured by biopsy. Thereafter, the tumor spread is determined.Base: history and clinical examination
At the beginning with a survey of the medical history (anamnesis of the patient), including questions about urination and sexuality. Subject of the clinical investigation is to evaluate the abdomen and genital organs (including DRE, see next paragraph). Furthermore there is a routine urine examination (eg with test strips, common to see under urine tests ).Position of the suspected diagnosis: Using DRE, PSA and TRUS
When suspicion of prostate cancer, a digital rectal examination (DRE) should be performed.The physician scans the prostate through the rectum (rectum) from from the finger (Latin digitus). Because the DRU is simple, quick and painless, it is one of the main methods to detect prostate cancer. It also makes it also detect tumors that do not form PSA (see below). A disadvantage is its low sensitivity (detection rate) and specificity ("probative value"): tumors are using DRU only become evident from a position-dependent minimum size (the back and sides from about 7mm in diameter), and the palpation alone (eg suspicious nodes) is still no evidence of tumor (For details on the DRU s digital rectal examination ).Prostate specific antigen (PSA) is formed by prostate cells and usually also increased by malignant. Therefore, with his blood levels increase the likelihood of prostate cancer. Rarely, the value is reduced for other reasons despite a tumor, and rarely forms a tumor little or no PSA. However, PSA shows no tumor, especially in the low range (with "normal values"), and even an increase (usually from 4ng/ml) may have other causes. However, the PSA level has a higher significance than DRU (see above) and TRUS (see below). This can be enhanced with special provisions (eg, density, slew rate and doubling time of PSA, percentage of free PSA) on. You should change the PSA level that is measured in any case, regardless of whether there are symptoms or not, the decisive factor is often the follow-up (see further hints aboutPSA testing ).
The transrectal ultrasound (TRUS) can be used as a complementary imaging modality for the diagnosis of prostate cancer. The prostate and its surroundings is presented with a high-resolution probe from the rectum. This change can be good track (good sensitivity), but their nature is hardly recognizable (low specificity): About two-thirds of prostate cancers arise in the picture is dark (hypoechoic), while the rest brighter (hyperechoic) or to not see is because the same internal structure and brightness as normal tissue (isoechoic). In addition, hides behind only about every third hypoechoic prostate cancer. New method can increase the validity of something (eg in Doppler visible increased tumor perfusion by contrast medium better tumor delineation and for more information see the TRUS transrectal ultrasound ).
Each of these three methods can have a positive (abnormal) findings revealed the tumor must be regarded as suspect and further clarified. However, none alone can detect even the smallest tumor safely. Supply all but three positive results, the probability of prostate cancer rises sharply.
Confirm the diagnosis: Using biopsy
Only with a biopsy (removal of tissue samples) can confirm the diagnosis. It is generally indicated when at least one of the following three is true: PSA value 4ng/ml, suspicious findings on DRE, striking increase in PSA. This 10-12 samples from different locations of the prostate from the from the rectum under TRUS control painless "punched" (transrectal prostate biopsy), possibly also from palpable lumps or TRUS visible herds (for details, also to educate, to validity of findings and for repeat biopsy s prostate biopsy ).The biopsy material is then processed and subjected to microscopic examination by a pathologist. If he finds therein cancer tissue (positive biopsy), it determines the type of the tumor (Typing) and their malignancy (grading, eg Gleason) a (For details, see classification of prostate cancer ). After negative (inconspicuous) biopsy can MRI ("MRI") is used as an additional imaging technique (special technology with the coil in the rectum, if necessary, special procedures such as MRI-spectroscopy).
Determination of tumor spread (staging): Especially with imaging techniques
Evidence of the spread of prostate cancer already give the PSA level and biopsy findings (eg number of samples involved, Gleason score). To estimate also nomograms (special tables, eg by Partin, Steuber or Briganti) can be used. Measures the spread with the TNM system (seethe growth and spread of prostate cancer ). The classification occurs with respect to the three categories of T, N and M are initially based on the findings of studies (ie, clinical = c as a sign in front of a category):Category T (tumor): To determine the local tumor spread (cT-category) the findings of DRE, TRUS biopsy and should be used. Other imaging techniques (eg CT , MRI ) are not necessary, but their results should be considered, if applicable.
Category N (of English node = node.): The regionären (surrounding) lymph nodes of the prostate are located in the pelvis. Your involvement can lead to an increase and with imaging techniques (eg, ultrasound, CT, MRI) is not recognized immediately (until about 1cm diameter).An investigation should be done only if the findings can influence the choice of treatment (eg if a = curative curative therapy is possible as a radical prostatectomy). Patients with a tumor the size cT3-4 or a Gleason score of 8 should get an MRI of the pelvic organs before a treatment decision. The most accurate diagnosis provides the surgical removal of lymph nodes (so-called open or laparoscopic diagnostic lymphadenectomy) followed by microscopic examination. You can come into question in a particular case, one can do it at a low risk for lymph node metastasis (cT1c and PSA below 10ng/ml and Gleason score to 6).
Category M (metastases): The first distant metastases are usually found in the skeleton, most likely in the lumbar spine and pelvic bones. To investigate which serves bone scintigraphy : purpose, a radioactively labeled substance is injected which accumulates especially in remodeling zones of the bone and its distribution can be measured. However, an enrichment proves no metastasis, and there are metastases that do not lead to enrichment. Therefore, if further clarification is needed. Special techniques such as SPECT and fluoride PET-CT (see also PET ) may increase the accuracy. Patients with a PSA level of more than 10ng/ml or a tumor the size cT3-4 or a Gleason score of 8 or bone pain (or an elevated or rise in alkaline phosphatase ) should receive a bone scan. In an unclear diagnosis or suspicion of bone metastasis instability from other radiological and, where appropriate neurological assessment should be responsible (eg, X-ray, MRI, CT). For the diagnosis of distant metastases at other sites serve the physical examination and various imaging techniques (eg, ultrasound, x-ray, CT, MRI).
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