Unlike for many other cancers, there are no standardized imaging protocols, apart from the use of transrectal ultrasound (TRUS), for the early detection and diagnosis of prostate cancer. This is a critical need. Prostate cancer is a disease for which it is crucial to detect and diagnose cancers early and accurately, both because early prostate cancer is usually without symptoms and because treatment side effects can be severe. Fortunately, new technologies are currently being developed, and even being used in some medical facilities, with promising results. By providing more specific and accurate detection and diagnosis results, these more sophisticated forms of prostate imaging and analysis will help in detecting early cancers, and in making the decision of whether to treat for prostate cancer when abnormalities are detected.

Currently, the following imaging technologies are used for early detection and diagnosis of prostate cancer. (For more information on imaging technology, see Cancer Staging).

• Transrectal ultrasound (TRUS), also called gray-scale ultrasound, is the most commonly used prostate imaging technology. It can accurately show the size of the gland, but it is not accurate in showing cancer lesions within the prostate, or for revealing extracapsular extension or spread to the seminal vesicles. The main uses of TRUS for prostate cancer are to guide biopsies and the placement of brachytherapy seeds.
• Standard T2-weighted magnetic resonance imaging (MRI) provides excellent anatomical images of the prostate and better structural tissue detail than any other imaging technology. T2-MRI can also show extracapsular extension, cancer spread to the seminal vesicles, and other information. Cancerous tissue may appear as areas of the prostate that look strikingly different from normal tissue on the T2-MRI image. However, standard MRI alone lacks specificity: that is, it isn't very good at telling cancerous from noncancerous abnormalities in prostate tissue.
• Advanced MRI techniques include diffusion-weighted MRI (DW-MRI), dynamic contrast-enhanced MRI (DCE-MRI), and MR spectroscopy imaging (MRSI). These techniques are considered functional types of MRI because they provide information about the body's metabolic functions, not simply its anatomy. Advanced MRI techniques improve the accuracy of MRI in differentiating cancerous tumors from noncancerous lesions in the prostate.
• Computed tomography (CT) has a limited role in prostate cancer detection and diagnosis because it is not good for detecting lesions within the gland itself. The main role of CT is to detect the spread of the cancer to lymph nodes and metastases to the bones, although MRI and bone scans are more sensitive for detecting the latter.
• Bone scans show whether prostate cancer has spread to the bones. Diseased areas of the skeleton show up as "hot spots" on the picture. However, hot spots can also show up in arthritic areas or where the bone has previously been injured, so further tests may be needed to confirm cancer.

More on this topic

Diagnosing Prostate Cancer (VIDEO)
Treating Prostate Cancer (VIDEO)
Prostate Cancer
Prostate Anatomy
Prostate Function
What Is Prostate Cancer?
Screening and Detection
Cancer Biopsy
Growth and Spread of Cancer
Imaging Diagnostics
Treatment Planning
Treatment

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