MRI Prostate

Magnetic Resonance Imaging (MRI) of the prostate has revolutionised the way that prostate cancer is diagnosed.

Furthermore, the surgeons at Sydney Urology Group utilise the information from the prostate MRI to plan bespoke treatment for their patients diagnosed with prostate cancer.

Prior to the widespread use of MRI, patients that were found to have an elevated PSA would undergo systematic, non-targeted biopsies throughout the prostate. Although prostate biopsy is a relatively minor procedure, when many core biopsies are taken, there is a higher risk of complications including bleeding (in the urine and semen), retention (particularly in men with larger prostates) and infection (especially if performed via a transrectal route).

At Sydney Urology Group we routinely order an MRI in patients with a rising PSA, or abnormal digital rectal examination, which allows a more targeted approach to prostate biopsy. This targeted approach, which can be done with MRI/US fusion technology, allows a more precise diagnosis of clinically significant prostate cancer, less complications and reduced diagnosis of insignificant disease. The urologists at Sydney Urology Group have published on optimal use of MRI for the diagnosis of prostate cancer.

A Medicare rebate for prostate MRI is available when the below criteria are met, which keeps the out of pocket costs down:

• for a person 70 years or older, at least two PSA tests performed within an interval of 1- 3 months have a PSA concentration of greater than 5.5 µg/L and the free/total PSA ratio is less than 25%.
• for a person under 70 years, at least two prostate specific antigen (PSA) tests performed within an interval of 1- 3 months have PSA concentration of greater than 3.0 ng/ml, and the free/total PSA ratio is less than 25%, or the repeat PSA exceeds 5.5 µg/L.
• for a person under 70 years with a relevant family history, at least two PSA tests performed within an interval of 1- 3 months have a PSA concentration greater than 2.0 ng/ml, and the free/total PSA  ratio is less than 25%, or the repeat PSA exceeds 5.5 µg/L. Relevant family history is a first degree relative with or has had prostate cancer, or suspected of carrying a BRCA 1 or BRCA 2 mutation.

When our patients have been diagnosed with prostate cancer, the surgeons at Sydney Urology Group will use the MRI information to plan the optimal treatment, individualised for each person.

As an example, figure 1 shows the MRI of a patient with Gleason 9 prostate cancer involving the anterior zone of the prostate (green arrows). As the nerves for potency are positioned on the other side (posterior aspect) of the prostate, a nerve-sparing robotic prostatectomy was able to be performed such that the patient was able to maintain his potency following the surgery.

In another example of how MRI is used to tailor curative treatment, figure 2 shows a 1cm lesion on the left side of the prostate. Because of its small size, and subsequent biopsies demonstrating Gleason 7 cancer in this lesion only, the patient was treated with focal therapy and was therefore able to avoid the side effects that can be associated with conventional whole gland treatment.