Accuracy of MR imaging for staging prostate cancer: a meta-analysis to examine the effect of technologic change

The purpose of this study was to summarize the accuracy of magnetic resonance (MR) imaging for staging prostate cancer and to determine the effect of high magnetic field strength, use of the endorectal coil, use of fast spin-echo (SE) imaging, and study size on staging accuracy.

A literature search and review yielded 27 studies comparing MR imaging to a pathologic standard in patients with clinically limited prostate cancer. Subgroup analyses examined magnetic field strength, use of an endorectal coil, use of fast SE imaging, publication date, and study size.

A summary receiver operating characteristic curve for all studies had a maximum joint sensitivity and specificity of 74%. At a specificity of 80% on this curve, sensitivity was 69%. Subgroup analyses showed that fast SE imaging was statistically significantly more accurate than conventional SE techniques (P < .001). Unexpectedly, studies employing higher magnetic field strength and those employing an endorectal coil were less accurate.

Seemingly small technologic advances may influence test accuracy. Early and small studies, however, may overstate accuracy because of publication bias, bias in small samples, or earlier studies being performed by the experts who developed the technology itself.