Evolution of prostate cancer detection by mpMRI-based screening: how we could reduce the number of unnecessary biopsies
Kazumi Kamoi, Koji Okihara, Fumiya Hongo, Yoshio Naya, Naitoh Yasuyuki, Iwata Atsuko, Terukazu Nakamura, Tsuneharu Miki
Department of Urology Kyoto Prefectural University of Medicine
Introduction: The best characterization of prostate cancer in individual patients will most likely result from a multiparametric (T2WI/DWI/DCE) exam using 3T magnetic resonance scanners. According to the evidence that patients with normal looking mpMRI (PI-RADS 1 or 2) rarely demonstrate clinically significant cancers, we have gradually changed to select patients who needed biopsy only with equivocally or definitely suspicious findings on MRI (PI-RADS 3 to 5). The aim of this study was to document the trend in the diagnosis of prostate cancer in our institute and to demonstrate the efficacy of MRI/ultrasound fusion technique for the detection of clinically significant prostate cancers.
Methods: All patients who underwent prostate needle biopsies with elevated PSA or abnormal DRE from Jan 2009 to Dec 2014 are evaluated. MRI/ultrasound fusion biopsy system (Urostation, Koelis, France) was installed in July 2011 and 74% (128/174) of biopsies were performed with this system in 2014. The percentages of patients who had mpMRI before biopsy, overall detection rates, significant cancer detection rates, repeat-biopsy rates are compared year by year. The cost for detecting one significant cancer was calculated by adding total costs for mpMRI and biopsies.
Results: The percentage of patients who had mpMRI before biopsy, overall detection rate, significant cancer detection rate in 2009 were 35% (59/170), 49% (84/170), and 41% (60/219), and increased to 93% (161/174), 82% (142/174) and 76% (132/174) in 2014, respectively. Repeat-biopsy rate was decreased from 26% to 14%. The cost for detecting one significant cancer decreased from 250,000 yen to 145,000 yen during the observation period.
The cancer detection rate has been improved with the maximum use of pre-biopsy mpMRI without compromising cost effectiveness.