Confirmatory Magnetic Resonance Imaging with or without Biopsy Impacts Decision Making in Newly Diagnosed Favorable Risk Prostate Cancer.

ABSTRACT

PURPOSE: We investigated how magnetic resonance imaging and post-magnetic resonance imaging biopsy impact decision making in men considering active surveillance. MATERIALS AND METHODS: We reviewed the records of men in the Michigan Urological Surgery Improvement Collaborative with newly diagnosed favorable risk prostate cancer. Following diagnostic biopsy the men were classified into 3 groups, including group 1-no magnetic resonance imaging, group 2-magnetic resonance imaging only and group 3-magnetic resonance imaging/post-magnetic resonance imaging biopsy. For the purposes of counseling and shared decision making magnetic resonance imaging results were deemed reassuring (PI-RADS™ [Prostate Imaging Reporting and Data System] 3 or less) or nonreassuring (PI-RADS 4 or greater). Similarly, if the diagnostic biopsy was GG (Grade Group) 1, post-magnetic resonance imaging biopsy results were deemed nonreassuring if there was any amount of GG 2 or greater. If the diagnostic biopsy was GG 2, post-magnetic resonance imaging biopsy results were deemed nonreassuring if more than 3 cores were GG 2, or there was more than 50% GG 2 in any individual core or any volume of GG 3 or greater. RESULTS: Of 1,461 men with favorable risk prostate cancer 1,223 (84%) did not undergo magnetic resonance imaging, 157 (11%) underwent magnetic resonance imaging alone and 81 (6%) underwent magnetic resonance imaging and post-magnetic resonance imaging biopsy. Of the men who underwent magnetic resonance imaging alone more with reassuring findings elected active surveillance than men with nonreassuring or magnetic resonance imaging findings (74% vs 35% and 42%, respectively). The highest rate of active surveillance was noted in men with reassuring post-magnetic resonance imaging biopsy regardless of whether magnetic resonance imaging was reassuring or nonreassuring (93% and 96%, respectively). CONCLUSIONS: Magnetic resonance imaging and post-magnetic resonance imaging biopsy drive decision making in men with newly diagnosed, favorable risk prostate cancer. Post-magnetic resonance imaging biopsy is a stronger driver of decision making than magnetic resonance imaging alone. This was demonstrated by the more than 90% of men with reassuring post-magnetic resonance imaging biopsies who elected active surveillance regardless of magnetic resonance imaging results.