Originally published 4/10/2016
The seven bullet points in the original blog below have stood the test of time since we first reported them in 2016. Four years later, the journal Nature published an article by some of the world’s experts in the use of multiparametric MRI (mpMRI).[i] Compare their 6 key points with those in our 2016 blog below:
- mpMRI is a tool for the diagnosis of prostate cancer (PCa) that may help with the problem of overdiagnosis (and therefore overtreatment).
- mpMRI should include four imaging sequences: T1-weighted images, T2-weighted images, diffusion-weighted images (DWI) and dynamic contrast-enhanced imaging (DCEI). (Note: these are the four sequences used by our Center, though some researchers are exploring the use of only two parameters, T2-weighted and DWI, if needed to shorten imaging time.)
- Interpretation and reporting of mpMRI must be carried out following standardized scoring systems (such as Prostate Imaging Reporting and Data System (PI-RADS) v2).
- The use of mpMRI-targeted biopsy has value for increasing the detection of clinically significant prostate cancer in both biopsy-naive and previous negative biopsy settings. (Note: Our center provides real time in-bore biopsy for superior diagnostic accuracy while limiting the number of needles necessary. Do not confuse fusion-guided biopsy with in-bore MRI guided biopsy, since fusion is often called “MRI-guided biopsy.” This is misleading. See our comparison chart for more information.)
- There is controversy over whether mpMRI before biopsy can definitively rule a biopsy in or out. According to the authors, in men with negative mpMRI, omitting a biopsy should be considered only when the clinical suspicion of prostate cancer is low.
- Improvements in inter-reader agreement, development of computer-aided diagnostic systems and assessment of biomarkers to use in combination with mpMRI are needed.
While there are areas of overlap with our earlier blog, the more recent points above might be thought of as the current “Bible” of mpMRI.
Sinking your mental teeth into a banquet of information can be as satisfying as sitting down to a 5-course feast. At least, that’s how I felt when I came across a well-written review called “Multiparametric MRI in Diagnosis of Prostate Cancer” by Sangeet Ghai and Masoom A Haider.[ii] I personally think it’s well worth reading, but be prepared for numerous technical terms like “morphologic” and “pharmacokinetic” that require frequent use of the internet to obtain definitions.
Here are some takeaway points that I’ve been writing about in my articles and blogs:
- Conventional TRUS biopsy overdetects insignificant prostate cancer (PCa) and underdetects anterior tumors until they are dangerous. This leads to inaccurate risk stratification and therefore mismatched treatments.
- A 3T magnet does not require use of an endorectal coil, and provides better quality images than a 1.5T magnet.
- The main parameters that can be used in various combinations are T2 weighted MRI (anatomic detail), diffusion weighted imaging (movement of water molecules in tissue), dynamic contrast imaging (tumor blood flow), and MR spectroscopy (metabolic biomarker differences between healthy cells and cancer).
- The most essential data is provided by combining T2 weighted and diffusion weighted imaging, which has been shown to be highly accurate. Adding in dynamic contrast and spectroscopic sequences can provide clarifying information.
- Training radiological readers on the simplified reporting system called PI-RADS makes interpretations more accurate and objective.
- Multiparametric MRI (mpMRI) should be done before biopsy in patients whose PSA and/or DRE are suspicious for PCa.
- mpMRI has a higher detection rate than another repeat biopsy for men who had one or more previous negative biopsies.
- mpMRI can help qualify men for active surveillance, and can be monitored by imaging. Together with tracking PSA, a suspicious change in a patient’s MRI is a better trigger for biopsy than monitoring PSA alone.
- MRI-guided targeted biopsy is preferable to conventional TRUS biopsy.
The authors cite 71 references, so you know they have “done their homework” in summarizing the current state of mpMRI. Interested readers who want to access those sources can use pubmed.com to find the abstracts (brief summaries) of the actual articles.
I continue to write about mpMRI in order to reach as many newly diagnosed PCa patients as possible. Many of them are not aware that such imaging exists, let alone how vital the information is before considering a biopsy. This excellent work underscores the value of mpMRI. Although reading it may require frequent stops to visit Wikipedia and other explanatory sites, it’s not that long and yet gives a wealth of information and data. Feel free to spread the word. The whole article is available here, if you want a worthwhile mental workoout.
NOTE: This content is solely for purposes of information and does not substitute for diagnostic or medical advice. Talk to your doctor if you are experiencing pelvic pain, or have any other health concerns or questions of a personal medical nature.
[i] Stabile, A., Giganti, F., Rosenkrantz, A.B. et al. Multiparametric MRI for prostate cancer diagnosis: current status and future directions. Nat Rev Urol 17, 41–61 (2020).
[ii] Ghai S, Haider MA. Multiparametric MRI in diagnosis of prostate cancer. Indian J Urol. 2015 Jul-Sep; 31(3): 194–201.