OncologyIs It Time To Consider A Role For MRI Before Prostate Biopsy?
UroToday.com - The prevailing view is that MRI has a limited role in the management of prostate cancer. Currently, the threshold for requesting a pre-treatment staging MRI is variable with most advocating this for only those classified as high risk localized prostate cancer, although some also advocate men with intermediate risk disease.
The rationale for this view is that verification of organ-confined cancer in men with a low risk of locally advanced disease using a test that is both expensive and time consuming is not warranted. It has arisen due to poor quality scans as a result of low-resolution magnetic field strengths combined with biopsy artifact. There is increasing evidence, however, that the threshold for requesting MRI should be lowered. This is related to improved technology, but is also linked to changes in diagnosis and management of prostate cancer, in which improved risk stratification is linked to reductions in treatment burden.
In this Review, we outline the artifact problem that occurs if MRI is used after biopsy. We also discuss the potential advantages in diagnosis and risk stratification that may be derived from using MRI prior to biopsy. Pre-biopsy MRI is currently nested within a small number of groups in France, Japan, India and in our own centre. We describe how local staging may improve as a result of using MRI and its association with improved clinical outcomes. Finally, we review the limitations in the current literature and recommend strategies that will overcome these limitations.
Advocating the widespread use of MRI prior to biopsy in a population of men with risk parameters for harboring prostate cancer has a number of advantages which may ultimately benefit the care these men undergo. Increasing the detection of prostate cancer that requires treatment whilst avoiding biopsy - and hence unnecessary treatment - in those with insignificant or no cancer are compelling arguments for this approach. Conferring better staging accuracy and determining disease burden may also lead to greater benefit for those who undergo treatment.
Key Points:
1. The role of MRI in prostate cancer management is controversial; most guidelines recommend its use only in high-risk patients based on evidence that used early-generation machines rather than using up-to-date data
2. The use of spectroscopy, dynamic contrast enhancement and diffusion weighting in combination with traditional T2-weight scans increases the accuracy of MRI to detect and stage prostate cancer
3. If multi-sequence MRI was applied in the pre-biopsy setting to overcome biopsy artifact, it could potentially increase the detection of significant prostate cancer, and decrease the diagnosis of indolent disease that requires no treatment
4. Such scans could potentially guide traditional therapy such as surgery and radiotherapy and also select those men with high-risk disease that require dose escalation whilst selecting groups with a low burden of disease that would be candidates for surveillance
Written by: H.U. Ahmed, M. Arya, R. Illing, A. Kirkham, C. Allen, A. Freeman and M. Emberton as part of Beyond the Abstract on UroTodya.com.
Author Print Biographies
HU Ahmed is an MRC Clinical Research Fellow and Specialist Registrar in Urology, and M Arya is a Specialist Registrar in Urology, both at the Division of Surgical and Interventional Sciences, University College London, UK. R Illing is a Specialist Academic Registrar in Radiology and A Kirkham and C Allen are both Consultant Radiologists, both at University College London Hospitals NHS Foundation Trust with specialist expertise in uro-radiology. A Freeman is a Consultant Histopathologist with expertise in uro-oncology based at University College London Hospitals NHS Foundation Trust. M Emberton is Reader in Interventional Oncology and Consultant Urological Surgeon, University College London as well as Clinical Director of the Clinical Effectiveness Unit, The Royal College of Surgeons of England, 35-43 Lincoln Inn Fields, London, UK.
Conflicts of Interest and Funding
Hashim Uddin Ahmed and Mark Emberton receive funding from the following charities: The Medical Research Council, Pelican Cancer Foundation, Prostate Research Campaign UK, Prostate Cancer Research Centre UK and St Peters Trust for work in focal therapy of prostate cancer. In addition, Mark Emberton receives funding from Negma Lerads, France (manufacturers of TOOKAD, a photodynamic agent used in prostate cancer therapy) and Misonix/Focus Surgery (manufacturers of the Sonablate® 500 HIFU device) as a Medical Consultant. Manit Arya, Clare Allen, Alex Kirkham and Alex Freeman have no conflicts of interest. None of the funding s had any role in the writing of this article.
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