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Approximately 15% of men with newly diagnosed prostate cancer have high-risk disease. Imaging is critically important for the diagnosis and staging of these patients, and also for the selection of management. While established prostate cancer staging guidelines have increased the appropriate use of imaging, underuse for high-risk prostate cancer remains substantial. Several factors affect the utility of initial diagnostic imaging, including the variable definition of high-risk prostate cancer, variable guideline recommendations, poor accuracy of existing imaging tests, and the difficulty in validating imaging findings. Conventional imaging modalities, including CT and radionuclide bone scan, have been employed for local and metastatic staging, but their performance characteristics have generally been poor. Emerging modalities including multiparametricMRI, positron emission tomography (PET)-CT, and PET-MRI have shown increased diagnostic accuracy and could improve accuracy in staging patients with high-risk prostate cancer.

PURPOSE OF REVIEW: In recent years, multiparametric magnetic resonance imaging (mpMRI) of the prostate has shown promise as a modality to identify areas of suspicion within the gland which correlate with cancer location and disease extent. However, optimal individualization of prostate biopsy using mpMRI relies on aligning the relative benefits of MRI-targeted approaches with the goals of biopsy. RECENT FINDINGS: For men with prior negative biopsies, mpMRI allows improved detection of occult high-grade cancers missed by repeat systematic biopsy but also has the potential to identify men who will not benefit from repeat biopsy due to a low likelihood of significant disease. For men with prior low-grade cancer diagnosis, the addition of MRI-targeted biopsy may identify those who are poor candidates for active surveillance by detecting high-risk disease without serial biopsies. For men without prior biopsy, mpMRI and targeted biopsy may help improve high-grade cancer diagnosis and significantly limit the detection of low-risk disease. SUMMARY: mpMRI of the prostate is a promising tool to address many of the shortcomings of traditional systematic prostate biopsy. Biopsy history plays a critical role in determining how to assess the potential advantages and disadvantages of prostate mpMRI in the context of each patient. Although these benefits have been suggested by published clinical outcomes data, there is a need for prospective validation of mpMRI and MRI-targeted biopsy in comparison with the current approach of systematic biopsy for all men, to define new paradigms for prostate cancer detection and risk stratification.