MRI guided prostate biopsy: The future for prostate cancer diagnosis?

Prostate cancer is the most common cancer in men, with a one in eight lifetime risk and 46,690 new cases diagnosed in the UK in 2014. Between 1979 and 2011 the incidence of prostate cancer in the UK has increased by 155%. The introduction of PSA testing and systematic transrectal ultrasound (TRUS) biopsies is responsible for a significant proportion of these new diagnoses. Over the same period survival rates for prostate cancer have dramatically improved, with a 10year survival rate of 25% in 1981 compared with 84% in 2011. While this is partly explained by improvements made in treatment protocols, the introduction of PSA testing and TRUS-guided biopsy has seen a significant shift in the disease stage at diagnosis with a large proportion of men diagnosed with early stage disease or clinically insignificant prostate cancer. Conversely, clinically significant prostate cancer (csPCa), remains prevalent and is the second most common cause of male cancer deaths in the UK and Ireland. Current methods for the investigation of prostate cancer with PSA testing and non targeted TRUS biopsy have a low sensitivity and specificity for the diagnosis of csPCa. Multiparametric prostate MRI (mpMRI) prior to prostate biopsy and subsequent image-guided targeted biopsy of suspicious prostate lesions are becoming standard practice. The combination of pre-biopsy mpMRI and image-guided targeted biopsy have been shown to significantly improve the sensitivity for detection of clinically significant prostate cancers. A number of approaches to MRI-guided prostate biopsy have been reported including ultrasound-guided fusion biopsy (transrectal or transperineal) and in-bore MRI-guided biopsy. This article will review the different approaches and highlight the advantages and challenges with each method. Ultrasound-guided MRI fusion biopsy