If you have a symptom or test result that suggests cancer, your doctor must find out whether it is due to cancer or to some other cause. Your doctor will ask about your personal and family medical history, and you’ll most likely have a physical exam as well as lab tests. Your visit may include a digital rectal exam, a urine test to check for blood or infection, and a blood test to measure the Prostate-Specific Antigen (PSA) level. It is important to remember, however, that PSA can be elevated in men for a variety of reasons, and a definitive diagnosis of prostate cancer can only be achieved by biopsy of the prostate.
- When a Biopsy is Needed
Prostate cancer is notoriously hard to detect. And since the 1980s, screening methods have not changed very much—until recently.
Depending on your age and risk factors, a yearly digital rectal exam is usually performed during your annual well visit. Your doctor will feel for a tumor. However, it only reaches part of the prostate. One downside is it only detects a tumor after it has become large enough to be at an advanced stage.
A PSA (prostate-specific antigen) blood test is also recommended. An elevated PSA level, which may indicate cancer, will prompt a biopsy. In this procedure, tissue samples are taken equally from all zones of the prostatic gland using a thin needle.
However, some men have other conditions that can cause varied PSA readings. In fact, about three-quarters of prostate biopsies come back negative.1This can be good news for many men, but sometimes it’s simply because conventional methods can easily miss the cancer. As PSA levels continue to rise, a number of biopsies may be needed before the cancer is found.
- Imaging the Prostate
For the past 30 years, the conventional method has been to use ultrasound to help guide where to insert biopsy probes. However, ultrasound images are not very clear for this use, and thus cannot detect the suspicious cancer sites. This is especially true for detecting early stages of prostate cancer.
So, this means it is basically a “blind” method where multiple probes are methodically inserted throughout the prostate. The hope is that if cancer is present, at least one of the needles will hit it. But in certain cases the cancer lesions can be easily missed leaving patients without needed treatment.
- Limits to Conventional Prostate Biopsy Methods
- Uses ultrasound alone, which does not image prostatic tissue very well.
- There are usually no clear lesions to target. At least 12 core samples are typically taken using a scattershot approach.
- If another procedure is required, it cannot accurately map with certainty where the earlier biopsy needle was inserted.
- False negatives, in which treatable (clinically significant) or “active surveillance” (low-risk) cancer is missed, can be as high as 35%.
- Up to half of detected lesions may not be clinically relevant. This can lead to pain and risk for unnecessary treatments.
- Is the only major cancer in which the blind biopsy of an organ is used for diagnosis.
- MRI Fusion Biopsy
Today, new medical imaging technology has greatly improved the accuracy of prostate cancer screening.
First, an mpMRI (a combination of multiple types and slices of MRI scans) of the prostate is taken and stored. Then, during an in- or outpatient procedure, an ultrasound probe is inserted into the rectum. The two images are fused into a 3D re-creation of the prostate, in real-time. This means that when the probe is moved, the image shifts along with it.
- Advantages of MRI Fusion Biopsy
- Combined 3D image has more contrast. This provides a much better image to guide the doctor to specific areas of concern.
- Two- to three-times more (92%) sensitivity for detecting prostate cancer than standard, non-targeted biopsy methods. This means less false-negative results for aggressive cancers.
- Much less guessing involved. Typically, only a few targeted cores are needed
- Each biopsy probe is accurately targeted, mapped and tracked. So, can return to the same biopsy sites with virtually pinpoint accuracy.
- Can actively track and monitor specific areas of the prostate (for active surveillance) to evaluate if and when treatment is necessary for non-life threatening tumors. Helps reduce over-diagnosis and unnecessary treatments.
Our goal is to provide you optimal care using the best tools available. Due to the many advantages of this screening method, we recommend it for many of our biopsy patients. If you have additional questions about MRI Fusion biopsy contact us today.
1 Barry MJ. Clinical practice. Prostate-specific-antigen testing for early diagnosis of prostate cancer. New England Journal of Medicine 2001;344(18):1373-1377.
Siddiqui MM, Rais-Bahrami S, Turkbey B, George AK, Rothwax J, Shakir N, Okoro C, Raskolnikov D, Parnes HL, Linehan WM, Merino MJ, Simon RM, Choyke PL, Wood BJ, Pinto PA. Comparison of MR/ultrasound fusion-guided biopsy with ultrasound-guided biopsy for the diagnosis of prostate cancer. JAMA. 2015 Jan 27;313(4):390-7. doi: 10.1001/jama.2014.17942. PMID: 25626035