Fusion biopsy of the prostate is a procedure that has developed over the last few years to more accurately diagnose localized lesions of the prostate.
This has become an important advance in the diagnosis of prostate cancer.
Over the years, studies have shown that many men who have random biopsies of the prostate — and also test for an elevated PSA blood level — are frequently deemed negative for cancer. But these random biopsies at times can miss a small cancer.
Conversely, MRI fusion biopsies radiologically image the prostate, and identify small lesions if they are present.
These MRI images are fused with the ultrasound image so that physicians can be more precise, and have much higher accuracy in their diagnosis, thereby decreasing false negative results.
Patients who undergo fusion biopsies usually have had one biopsy before their insurance company will allow for an MRI of the prostate. In these patients, if there is an increasing PSA or a palpable abnormality, an MRI is frequently ordered.
This MRI is done with contrast dye. Patients who have an allergy to the contrast, or who have defibrillators, pacemakers, or electrical stimulators are not candidates for an MRI of the prostate. But for the right candidates, the radiologist then uses these images to look for specific lesions based upon the contrast diffusing into the prostate gland and specifically into a lesion.
Lesions are graded from levels one to five. Grades four and five are much more likely to indicate the presence of cancer, whereas grades one and two are very unlikely to be cancerous. Grade 3 is indeterminate.
Once the MRI shows a lesion, that image can be fused with an ultrasound image, to more accurately biopsy that lesion.
In summary, a fusion biopsy can help lower the number of unnecessary biopsies, and is a technique that provides more accuracy than random 12 or 14 core biopsies, especially on patients who have had negative random biopsies in the past but are experiencing increasing PSA levels.
It is important to note, no single imaging or blood test should ever be relied upon on its own. If a patient has a normal MRI, but there is some suspicion based upon blood test results or physical examinations, a biopsy of the prostate is still recommended.