Errors in lesion targeting prompts MRI-targeted biopsy misses of cancer

Magnetic resonance imaging (MRI)-targeted biopsy misses of clinically significant cancers seldom occur, but such rare cases are mostly caused by errors in lesion targeting, which underscores the importance of accurate coregistration and targeting when using software-based fusion platforms, according to a study. Moreover, some patients harbor MRI-invisible lesions, which cannot be targeted by MRI platforms.

The authors enrolled 2,103 patients in this prospective study that compared cancer detection rates between transrectal MRI-targeted fusion biopsy and systematic 12-core biopsy. Those with an elevated prostate-specific antigen (PSA), abnormal digital rectal examination, or imaging findings concerning for prostate cancer underwent MRI and subsequent MRI-targeted and systemic biopsy in the same setting.

The subset of patients with grade group (GG) ≥3 found on systematic biopsy and GG ≤2 cancer or no cancer on MRI-targeted biopsy was classified as MRI-targeted biopsy misses. The cause of such misses was established through a retrospective analysis of the MRI and MRI-targeted biopsy real-time screen captures.

Finally, the authors conducted multivariable logistic regression analysis to compare baseline characteristics of patients with MRI-targeted biopsy misses to GG-matched patients whose clinically significant cancer was detected by MRI-targeted biopsy.

Over the study period of 2007 to 2019, 41 men (1.9 percent) were classified as MRI-targeted biopsy misses. Most of these misses were attributable to errors in lesion targeting (n=21, 51.2 percent), followed by MRI-invisible lesions (n=17, 40.5 percent), and MRI lesions missed by the radiologist (n=3, 7.1 percent).

Logistic regression analysis revealed that lower Prostate Imaging–Reporting and Data System (PI-RADS) score correlated with having clinically significant cancer missed on MRI-targeted biopsy.

“The presence of a low PI-RADS score despite a high PSA is suggestive of harboring an MRI-invisible lesion,” the authors said.