MRI and MRI-guided biopsies — a new Cochrane review

Cochrane reviews are structured, systematic, focused reviews of evidence in the field of medicine that either support or do not support specific forms of diagnosis and management of patients with or suspected of having particular disorders.

A newly published Cochrane review by Drost et al. has addressed the topic of “Prostate MRI, with or without MRI‐targeted biopsy, and systematic biopsy for detecting prostate cancer“, and had just been published by the Cochrane Library.

Basically, this review again confirms that:

  • The availability of high quality prostate MRI scanning techniques is beneficial in the assessment of a variety of men at risk for clinically significant, localized or locally advanced prostate cancer, but that
  • Of 1,000 men at known risk for prostate cancer, when 300 of these men actually have clinically significant prostate cancer,
    • MRI scanning alone will accurately identify clinically significant prostate cancer 273/300 men, but will “miss” 27/300 (about 10 percent) of those clinically significant prostate cancers.
    • MRI scanning alone will accurately identify 259/700 men as not having prostate cancer but will misclassify 441/700 men as also having clinically significant prostate cancers.
    • MRI-guided biopsy alone will accurately identify clinically significant prostate cancer in 240/300 men but “miss” 60/300 of those clinically significant prostate cancers
    • MRI-guided biopsy alone will accurately identify 658/700 men as not having prostate cancer but will misclassify 42/700 men as also having clinically significant prostate cancers.
  • When comparing the MRI pathway to systematic biopsy,
    • In a mixed group of men who may or may not have had a prior biopsy, the MRI pathway is 12 percent more likely to make the correct diagnosis than a systematic TRUS-guided biopsy.
    • In a group of biopsy-naive men, the MRI pathway is 5 percent more likely to make the correct diagnosis.
    • In a group of men who have had a prior, negative biopsy, the MRI pathway is 44 percent more likely to make the correct diagnosis.

In other words, the availability of modern forms of MRI scanning has greatly improved the accuracy of prostate cancer diagnosis. But …

MRI scanning alone and MRI scanning followed by MRI-guided biopsy alone are not (yet) of a sufficiently high standard to guarantee the accurate diagnosis of clinically significant prostate cancer and to distinguish this from clinically insignificant prostate cancer.

The authors go on to state that, “further research in this area is important”.

The “New” Prostate Cancer InfoLink is of the opinion that — at this time — most patients will get the most accurate diagnosis of their risk for prostate cancer by having an MRI scan followed by an MRI/TRUS fusion-guided biopsy that combines a systematic 12-core biopsy and targeted biopsy of additional lesions that appear suspicious on an MRI scan.

We further are of the opinion that any patient who has been diagnosed with localized prostate cancer on the basis of a systematic biopsy alone, and who is considering active surveillance as his initial management option, should have his initial biopsy confirmed, within 12 months of his initial biopsy, by an MRI scan and an MRI/TRUS fusion-guided biopsy or by an MRI scan and an appropriate form of saturation biopsy.

3 Responses

  1. I hear from many patients who insist on an mpMRI-targeted biopsy for a first biopsy. They read about others getting mpMRIs often in any of several situations (e.g., second biopsy when suspicion remains, confirmation biopsy for AS) and fail to distinguish the difference. This analysis that shows there is only a 5% improvement in accuracy may mollify them. In Europe, where MRIs are much less expensive, perhaps that 5% improvement meets their cost/benefit standard.

  2. It seems to me that, for a biopsy-naive patient, the MRI route has an advantage beyond the 5% greater accuracy: that is, that if the MRI does not show any lesions, the doctor may decide to skip the biopsy. So there is a chance that the patient will be spared a biopsy, which to my mind is a bigger advantage than 5% greater accuracy.

  3. Thank you for posting this very important review which more or less summarizes the reports from this past year of limited prostate mpMRI sensitivities (est. 50%) and prostate cancer volume assessment (misses 2/3) when comparing post-op RP whole-mount pathology with pre-opMRI data.

    In the US, right now, combining MRI-targeted biopsies with random biopsies is the best way we have of diagnosing prostate cancer in suspected individuals. That is not to say that MRI is adequate to follow patients on AS; Dr Reiter at UCLA has said repeat biopsies are needed for following AS patients.

    For those who are fed up with all this uncertainty in the diagnosis of prostate cancer, esp. in those with a rising PSA and negative prior MRI biopsies, there is an alternative, i.e., going outside of the US and getting a prostate PSMA PET/CT scan. The out-of-pocket costs would be about $7,500 if going to Hong Kong Hospital from the West Coast (airfare $4,000; scan $2,500).

    Even with the scan and that information in hand, that does not mean it is clear sailing afterwards. One would still need the targeting MRI and biopsy and treatment if the biopsy was positive. One would need to get the doctors you are seeing to use the PSMA PET/CT information, as some could say they are unfamiliar with this type of scan and do not know how to interpret and apply it (to MRI reading, surgery, and other treatment decisions). You might just have to be prepared to argue your own case. That is where reading (and following this site) and preparation comes in to help you with this.

    The good news is that there is something better out there to diagnose prostate cancer, and one would hope that the FDA will soon approve PSMA PET/CT for diagnosis of prostate cancer, but it is hard to say when this will happen. One does have other alternatives nonetheless. That’s the point of this post.

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