- Recent studies suggest that an MRI can reduce the need for biopsy in certain patients suspected to have prostate cancer.
- MRIs slice images while biopsies slice tissue.
- MRI ultrasound-guided fusion biopsies improve outcomes and lower the number of repeat biopsies.
After skin cancer, prostate cancer is the most common male cancer, and it is also the most age-related. Men older than 65 have a one-in-six chance of developing prostate cancer with more than 248,000 diagnoses estimated for 2021.
Black men can have a high risk of prostate cancer, as they’re 2.5 times more likely to develop the disease and more likely to die from it.
On a positive note, the mortality rate associated with this disease continues to decrease, according to the World Journal of Oncology. This is likely due to increased awareness of screening and advances in diagnostic testing, which lead to earlier intervention.
When deciding between a prostate MRI vs. biopsy, there are a few things to understand, such as differences in testing procedures, side effects, and accuracy.
The Prostate Gland
An integral part of the male reproductive system, the prostate gland is located deep inside the pelvis just below your bladder. It is a fleshy donut-shaped organ that encircles the tubes carrying urine and semen. As the term “gland” suggests, the prostate secretes a liquid that merges with semen in the ejaculatory duct. Within the liquid is an enzyme called PSA or prostate-specific antigen.
PSA also offers important clues to your overall prostate health. If you are over the age of 50 or are experiencing symptoms related to prostate dysfunction, your doctor may order a blood test to measure the amount of PSA circulating in your bloodstream. While healthy levels vary based on age and ethnicity, significantly elevated levels may raise concerns.
What Are the Symptoms of Prostate Dysfunction?
Not all prostate cancer patients experience prostate symptoms. However, according to the National Institute on Aging, the most common symptoms of prostate problems include:
- Increased frequency of urination
- Increased nighttime urination
- Blood in urine
- Blood in semen
- Painful urination
- Painful ejaculation
- Urinary incontinence including dribbling
- Decreased urine flow
- Sexual dysfunction
- Painful back, hips, pelvis, or rectum
If you are experiencing these symptoms, please seek medical care as soon as possible. They may indicate inflammatory conditions like BPH (benign prostatic hyperplasia — age-related prostate enlargement), prostatitis (prostate gland swelling and inflammation), an infection of the prostate, bladder, or other organs, or other diseases like STDs and cancer.
What Is Prostate Cancer Screening?
The diagnosis of prostate cancer usually follows a biopsy prompted by a significantly elevated initial PSA level, an increase in PSA levels over time, or an abnormal digital rectal examination.
According to JAMA, patients with a prostate cancer history benefit from extended PSA monitoring. Elevated PSA levels may help determine when to go in for a prostate MRI and hopefully avoid unnecessary or repeat prostate biopsies.
The American Journal of Men’s Health reports that prostate cancer diagnosis occurs most often in men older than 50.
Other factors influencing the rate of prostate cancer are ethnicity and family history. Screening is vital because localized prostate cancer sometimes causes no symptoms or warning signs.
The Digital Rectal Exam (DRE)
The prostate gland comprises three zones. Most cancers originate in the peripheral zone. Proctologists, urologists, and oncologists are trained to feel this area while performing a digital rectal exam (DRE).
Here, “digital” doesn’t refer to technology. Instead, it refers to the fingers (digits). In a DRE, your doctor inserts a well-lubricated gloved finger gently into the rectum to reach the prostate. Prostate enlargement and suspicious lesions may be felt during a DRE.
What Is Prostate-Specific Antigen Testing?
PSA testing has been around since the 1990s and has decreased cancer metastases and the death rate from prostate cancer. However, this test has significant limitations.
PSA testing has a false-positive rate as high as 70%. This means many men with elevated PSA levels will be referred for unnecessary biopsies. You’re probably thinking, “there has to be a better way.”
Recommended reading: What Can Skew a PSA Test? 6 Factors To Consider
What’s worse than a false-positive PSA? A false-negative biopsy.
Research shows that 35% of biopsy results are false negatives. This means despite the invasive sampling of tissues, cancer can go undetected and continue to grow while symptoms persist.
That’s why having a prostate MRI before a biopsy is preferable. It shows the location of potential cancer, which helps direct the biopsy sampling.
Before you decide to get a prostate MRI vs. biopsy, here are a few things to know.
What Is an MRI?
What makes an MRI different from other medical imaging techniques like X-rays and CT scans?
X-rays take projection images of hard tissues like bones, while CT scans take images of both hard bony tissues and soft tissue. Both systems use ionizing radiation, which passes through the body to create images that are transferred to photographic film or to a video monitor.
An MRI works differently. Magnetic resonance imaging uses a magnetic field to create sound waves that are received, digitized, and displayed in real-time. When tissue is abnormal, its composition changes, so the images reflect damaged areas.
What Is a Prostate Biopsy?
There are two main types of prostate biopsies — transrectal ultrasound (TRUS) guided biopsies — and transperineal biopsies. As the former tends to be more common, we’ll focus on this method.
(TRUS) biopsies use ultrasound guidance with a biopsy tool to snip core samples from the prostate gland. An ultrasound probe and biopsy tool are introduced into the rectum where a biopsy needle penetrates the rectal wall and enters the prostate. The procedure is repeated up to 12 times.
Transrectal prostate biopsies are outpatient or in-office procedures that require only numbing medicine. Passing a needle through the rectum and into the prostate places you at risk of infection. To minimize the risk of infection, urologists commonly prescribe antibiotics beforehand.
Other complications from prostate biopsies include:
- Blood in urine, semen, and stool
- False results
- Need for repeat biopsy
What Is Multiparametric-Magnetic Resonance Imaging?
An MpMRI or multi-parametric magnetic resonance imaging uses innovative technology to create a more detailed 3D image of your prostate than a standard 2D MRI scan. AI software combines different kinds of images to help with detecting prostate cancer.
- T2-weighted images reveal prostate zones and suspected tumors and can be used to rule out insignificant cancers.
- Diffusion-weighted images (DWI) show areas where there is a build-up of fluid because of restricted flow.
- Dynamic contrast-enhanced (DCE) MRI scans reveal a jumble of new blood vessels that feed cancer growth.
Traditionally, insurance companies require a biopsy before an MRI, even though a biopsy has more risks. However, at ezra, you can schedule an MRI of the prostate and 12 other organs any time.
When a Targeted Biopsy Is Necessary
Despite advances in MRI technology, there will be times when a prostate biopsy is a needed follow-up. Fortunately, there is something safer, less painful, and more accurate than prostate biopsy procedures (like TRUS).
What Is an MRI Fusion Biopsy?
In a fusion scan, an MRI and transrectal ultrasound team up with a systematic biopsy to allow doctors to pinpoint suspicious lesions in the prostate. This low-risk technology leads to greater accuracy in high-grade cancerous lesions.
There are situations where an MRI carries some risk, such as if you have an implanted medical device, tattoos, dental implants, or metal body modification. In this case, ultrasound fusion targeted biopsy can help.
How a Prostate MRI vs. Biopsy Can Improve Detection
The good news is that early prostate cancer detection means clinically significant prostate cancer can be highly curable. However, such prostate cancers, if left untreated, have a slow, steady, and predictable behavior with the potential for local tumor progression and spread. Fortunately, detection rate improves with radiology technologies like an MRI, including the multiparametric MRI.
Unfortunately, men usually have to first get a prostate biopsy before their health insurance will cover a prostate MRI with IV contrast. This is backwards because a prostate biopsy has notable risks (infection, bleeding and sometimes, erectile dysfunction). Conversely, a prostate MRI is non-invasive and therefore less risky.