Multiparametric MRI-ultrasound fusion biopsy (mpMRI fusion biopsy) has multiple limitations, including cost, interobserver variability, and low diagnostic accuracy for clinically significant cancer in the anterior prostate,1 says E. David Crawford, MD. Furthermore, according to the AUA Policy Statement on mpMRI in the diagnosis, staging, and management of prostate cancer, which provides a framework for clinical practice, mpMRI itself has a limited role as a diagnostic tool.2
Therefore, mpMRI fusion biopsy cannot be considered as the gold standard for prostate cancer diagnosis, according to Dr. Crawford, professor of surgery, urology, and radiation oncology, and head of the section of urologic oncology, University of Colorado Anschutz Medical Campus, Aurora.
“The coincidental timing of the advent of mpMRI technology with a higher field strength and the growing controversy about overdiagnosis and overtreatment of insignificant prostate cancer generated interest in using mpMRI to improve biopsy accuracy and efficiency. Then, as evidence began to accumulate showing that the MRI ‘fingerprint’ could be used to ferret out significant prostate cancer on transrectal biopsy, companies developed targeted biopsy platforms based on fusing the mpMRI image to the live transrectal ultrasound image for targeted biopsy,” Dr. Crawford said.
“Available evidence shows that these systems provide good accuracy for striking the lesions identified on mpMRI and, compared with systematic biopsy, increase the detection rate for higher grade cancers while decreasing detection of lower grade lesions. However, numerous studies also show that the accuracy of mpMRI fusion biopsy is not much better than cognitive fusion biopsy and that MRI fusion biopsy misses a significant number of high-grade cancers that are detected by 12-core systematic biopsy. Therefore, it cannot be relied on as the gold standard for prostate cancer diagnosis.”
“In fact, most centers offering MRI fusion biopsy combine it with 12-core systematic biopsy,” said Nelson Stone, MD, professor of urology and radiation oncology, Icahn School of Medicine at Mount Sinai, New York.
The performance limitation of mpMRI fusion biopsy is highlighted by the results of many studies that show it misses between 5% and 35% of high-grade cancers, including relatively large lesions.1,3