AUA 2017: Multiparametric MRI – When, Who, and How to Interpret?
Dr. Moore started her talk by noting that PSA testing in the UK is not necessarily the same as it is in the US, mentioning that <10% of men have a PSA test. The Prostate Cancer Risk Management Programme guidance from the Public Health of England states that “the PSA test is available free to any man aged 50 or over who requests it, after careful consideration of the implications.” Dr. Moore explains that the referral is made as ‘urgent’ when there is truly suspected cancer. This means that the patient’s 1st appointment is within 14 days, time from referral to diagnosis is 31 days, and time from diagnosis to treatment is 31 days. The NICE guidelines have been in place for prostate MRI in the UK since 2014. These guidelines state that MRI is indicated for men with a negative 10-12 core TRUS biopsy to determine whether another biopsy is needed and the biopsy is not offered if the MRI is negative. A second indication for MRI is for men with histologically proven prostate cancer if knowledge of T and N stage will affect management. Finally, MRI is also indicated for men on active surveillance (AS) at the outset of AS or in cases if there is concern about clinical or PSA changes during surveillance. Prostate MRI is performed in the UK using a 1.5T (minimum) or 3T (optimal) system, without an endorectal coil. In the UK, 79% of radiologist report doing an MRI prior to biopsy and that 50% use dynamic contrast enhancement and diffusion weighted imaging, while 39% report that MRI reduces the number of men who got on to biopsy. At Dr. Moore’s institution, they perform what she describes as a “one stop shop” of an MRI in the morning, followed by a read of the MRI by a consultant radiologist, and a transperineal biopsy in the afternoon, if necessary. Dr. Moore notes that MRI is increasingly becoming common as a triage test and that it is mandated by NICE for men suitable for radical treatment. Importantly, dedicated prostate MRI radiologists are contributing regularly to multi-disciplinary treatment recommendations.
Dr. Pinto from the NIH then offered the US experience with mpMRI. Dr. Pinto is a thought leader in the field of mpMRI and offers a well-balance and well-reasoned approach to mpMRI. Dr. Pinto notes that PSA leads to a systematic 12 core prostate biopsy blind to the tumor(s) location and that prostate cancer is the only solid-organ tumor diagnosed without image guidance in the hopes of accidentally ‘hitting’ the tumor. Dr. Pinto then listed a number of indications for when mpMRI may be used: (i) screening with MRI and targeted biopsy, (ii) after screening PSA test, (iii) after PSA screening and negative TRUS biopsy with continued concern for prostate cancer, (iv) active surveillance, both in the setting of selection and follow-up, (v) pre-op guidance for focal therapy, (vi) pre-op guidance for surgery. In the setting of PSA screening and negative TRUS biopsy, Dr. Pinto astutely notes that the risk of prostate cancer doesn’t change with increasing negative prostate biopsies. The AUA/SAR guidelines advocate for MRI in these settings. In the setting of AS, Dr. Pinto states that MRI can be helpful in a number of circumstances, namely (i) detecting higher grade or volume tumors who would theoretically be disadvantaged if put on AS, (ii) interval MRI to decrease frequency of biopsies, (iii) allow patients to feel more comfortable with AS, and (iv) allow urologists to feel more comfortable with AS. As Dr. Pinto concludes, he feels that the role of mpMRI and targeted biopsy in the diagnosis and treatment of prostate cancer needs further research and clinical trials before becoming standard of care in the US.
Presented by: Caroline Moore, University College London, London, UK; Peter Pinto, National Cancer Institute, Bethesda, MD, USA
Written By: Zachary Klaassen, MD, Urologic Oncology Fellow, University of Toronto, Princess Margaret Cancer Centre
Twitter: @zklaassen_md
at the 2017 AUA Annual Meeting - May 12 - 16, 2017 – Boston, Massachusetts, USA