Can Prostate Cancer Be Detected With an MRI?
(By Jeni Crockett-Holme)
Keywords: Prostate cancer, Imaging, MRI, Diagnosis, Biopsy
Multiparametric MRI (mpMRI) is an imaging technique that can detect large and higher grade tumors by visualizing specific areas of anatomy, using high contrast in soft tissue and high resolution . Its use with prostate biopsy allows targeted tissue sampling and has improved detection of prostate cancer. This capability suggests that mpMRI may be able to help differentiate low-risk prostate tumors from larger, more aggressive ones that require intervention (clinically significant disease).
A review of the prostate cancer literature was performed to determine how accurately mpMRI detects aggressive prostate cancer. Twelve studies published between January 1, 2000, and September 30, 2014, were selected. In these studies, prostate biopsies were performed only in areas of cancer that were visible on MRI. The patients had an average age of 62–65 years and included men who had not had a prostate biopsy before and men whose previous biopsy had been negative for prostate cancer.
In the reviewed studies, mpMRI accurately detected clinically significant prostate cancer in 44–87% of men who had not been biopsied previously or who had had a negative biopsy. The criteria for determining whether prostate cancer was “clinically significant” varied among the studies. As the threshold for clinical significance increased, mpMRI was less likely to correctly identify higher risk disease but was more likely to rule it out. mpMRI had the ability to accurately rule out significant disease 63–98% of the time.
What do the results tell us?
The findings suggest that mpMRI detects higher risk prostate cancer two to three times more accurately than the currently used ultrasound-guided biopsy technique. Biopsying only areas of cancer visible on MRI may have limited the patient population studied, but this limitation is acceptable because of the strong ability of the technique to rule out higher risk disease. This ability makes mpMRI useful for choosing which patients to biopsy.
The ability of mpMRI to accurately detect higher risk prostate cancer gives it potential to help reduce overdiagnosis and overtreatment of low-risk disease. Because mpMRI can help rule out clinically significant prostate cancer, the need for prostate biopsy based on PSA level could be reduced or eliminated. Further research is needed to evaluate and optimize this approach.
 Fütterer JJ, Briganti A, De Visschere P, et al. Can clinically significant prostate cancer be detected with multiparametric magnetic resonance imaging? A systematic review of the literature. Eur Urol 2015;68:1045–53.
Link to prostate cancer glossary: http://patients.uroweb.org/fileadmin/files/english/PCa/Glossary_of_terms_prostate_cancer.pdf