Multiparametric MRI


Reasons for prebiopsy multiparametric MRI
What if an MRI is performed before prostate biopsy? There are several advantages to such an approach.
Firstly, some men may be so reassured by a negative MRI that they decide not to have a biopsy at all. We know that a very high quality MRI (ideally at 3T) is, if negative, more reassuring about the absence of tumour than a negative biopsy, and some men decide to go no further, and to have their PSA checked regularly, and perhaps another MRI at an interval. If they decide on biopsy, and that is negative too, they are very unlikely indeed to have a cancer that will harm them.
Secondly, we can detect most significant tumours on MRI, so that the biopsies can be targeted to the suspicious area. This stops us missing tumours that lie in difficult to reach places (around 10% of significant cancers are completely missed by standard biopsy because of where they lie, but picked up by MRI) and it also helps us to be sure that the sample is representative: sometimes random biopsies just shave the edge of a large tumour, leading us to underestimate how much there is.
This leads on to the third advantage of MRI before biopsy. If a small amount of tumour is detected, MRI can check that this is not the edge of a large amount, or that there is a larger tumour in the front of the prostate. Active surveillance is unsuccessful in some men precisely because of such undetected tumours, most of which can be seen with MRI.
Finally, the finding of a significant cancer usually means that staging is required to detect spread outside the prostate. Radiologists who have looked at MRI images both before and after biopsy have no doubt that they are degraded for several months by the effects of bleeding from the biopsy: the best quality staging scan is undoubtedly one done before any of this has occurred - before the biopsy.
In all three cases then: whether no disease is found, a small amount, or a significant amount, MRI is likely to be useful. This is why most of the urologists and radiologists at Nuada would see it as the optimal first step in a man presenting with a raised PSA.