Negative Predictive Value of Multiparametric Magnetic Resonance Imaging in the Detection of Clinically Significant Prostate Cancer in the Prostate Imaging Reporting and Data System Era: A Systematic Review and Meta-analysis

Abstract

Reviewer #4: The authors are still failing to take the problem of heterogeneity seriously. The latest response was "well, yes, the results are all over the place, but most results are pretty good". First off, it is not at all clear to this reviewer that a negative predictive value of 85%, the threshold used by the authors, is acceptable. Would most patients be happy to be told that they only have a 15% risk of high-grade cancer, so not to worry about it? That is approximately the risk for a PSA of 10. How many urologists would argue against giving a biopsy to a man with a PSA of 10?Second, the point about heterogeneity is absolutely not to find out where the majority of results lie. For instance, if this was a meta-analysis of complication risk after abortion, and there was gross heterogeneity, with most clinics having very low rates and a few having very high rates, I'm pretty sure the conclusion wouldn't be only that "abortion is a safe procedure". More likely, there would be something about there being some unsafe clinics, and then an analysis to determine the characteristics of those clinics (e.g. solo practice) or a call for further research to determine why some clinics have poor outcomes. The current paper reads as if the authors came up with the conclusion first and then went through the motions of reporting forest plots and I2 statistics and so on. The conclusion that "Multiparametric MRI of the prostate is an accurate test for ruling-out clinically significant prostate cancer" is simply not an appropriate reflection of the data presented by the authors.Formatted: Font: Bold Commented [AL1]: I know we'd already done it but we don't need to point that out to AV. Hopefully he'll think we've now spotted the wisdom of his words and made the change requested. Don't want to give him any reason to dig his heals in.

Positive Predictive Value of Prostate Imaging Reporting and Data System Version 2 for the Detection of Clinically Significant Prostate Cancer: A Systematic Review and Meta-analysis

“…In this regard, a recent systematic review analyzed the variability of the NPV of mpMRI for the detection of csPCa in a total of 42 studies including 7321 patients [7], demonstrating that mpMRI can reliably exclude the presence of csPCa in case of nonsuspicious lesions. Complementary to this, defining PPV is aimed at assessing whether positive mpMRI can reliably support the presence of csPCa.…”

What to expect from a non-suspicious prostate MRI? A review

“…A systematic review and meta-analysis from the European Association of Urology Prostate Cancer Guidelines Panel including studies published between 2005 and 2015 estimated a combined negative predictive value between 67% and 88%, depending on the overall prostate cancer prevalence [3]. A very recent review considering various definitions of non-suspicious mpMRI and clinically significant cancer provided an estimated NPV of 90.8% of a PIRADS/Likert 1-2 MRI for ISUP grade ³ 2 disease in biopsy-naïve patients [4].…”

How Should Molecular Markers and Magnetic Resonance Imaging Be Used in the Early Detection of Prostate Cancer?

“…While data suggest that targeting cores to regions abnormal on MRI finds more highgrade cancer [1], there are concerns that this constitutes overgrading [2]. 5 Travel time and access: Given that MRI characteristics vary greatly between centers [3] and that high-volume centers are likely to have better outcomes, strategies involving MRI would be disfavored for individuals living far from a high-volume center or who have other barriers to access, such as insurance.…”