Originally published 7/27/2015
“Optimal” is the word used by D’Agostino, et al. (2020)[i] to describe pure in-bore MRI-guided targeted biopsy for the diagnosis of prostate cancer (PCa). Their finding that real time MRI needle guidance is superior to other biopsy approaches is based on an analysis of 142 patients who underwent in-bore targeted biopsies. Of the study population, 76 (53.5%) had never had a biopsy, while 66 (46.5%) had a history of previously negative random TRUS biopsies. Out of the total group, 75 patients (52.8%) had positive biopsies, out of which 54 were clinically significant (80.5%). The authors write that their study confirmed the greater detection rate of clinically significant PCa by in-bore MRI-guided biopsy, “with a very low number of cores needed and a negligible incidence of complication, especially in patients with a previous negative biopsy.” Similarly, after reviewing a number of randomized trials, Gurgitano, et al. (2020)[ii] note that in-bore biopsy “appears to be advantageous in reducing the overall number of biopsies performed, as well as in reducing the diagnosis of clinically insignificant disease while maintaining or improving the diagnosis of clinically significant PCa (cs-PCa).” In a nutshell, the primary benefits of in-bore prostate biopsy are: a) fewer needles, which offers lower side effect risks; b) better diagnosis of clinically significant PCa; and c) better identification of insignificant PCa that does not require immediate treatment. In the landscape of PCa detection and diagnosis, these three advantages make in-bore biopsy a standout.
Who invented the microscope? Credit for putting multiple lenses in a tube in order to gain a magnified view goes to two Dutch lens makers in the 1590s, Zacharias Jansen and his father, Hans. One of the first uses of microscopy in medicine occurred around 1650 when a Jesuit priest named Athanasius Kirchner saw little “worms” in blood samples, and he thought they might be connected to the plague. Medicine would not be where it is today without the ability to examine the sources of disease at great magnification.
Diagnosing prostate cancer currently requires a needle biopsy to remove very tiny threads of prostate tissue for evaluation under a microscope. (You can see a pathologist using a microscope to examine tissue, and how the magnified tissue looks, at http://www.hopkinsmedicine.org/hmn/F02/feature2.html) Until very recently, the standard biopsy has been guided by transrectal ultrasound (TRUS guided biopsy) and usually involves 10-14 systematic but random needles. Thanks to multiparametric MRI (mpMRI), the biopsy need not be random because the scan shows any locations that are suspicious for tumor.
However, a targeted biopsy done under real-time MRI (MRI guided targeted biopsy) is not yet feasible for everyone. Many urologists, who lack access and training for the use of MRI, rely on some form of co-registration or “fusion” of previously captured MR images with real-time ultrasound (MRI/US fusion guided biopsy). There are two kinds of fusion: a) cognitive fusion means the doctor looks at the MR images and mentally calculates where to direct the TRUS guided biopsy needles, and b) computer software that merges the two types of imaging and creates a 3D “cartoon” showing the suspicious area and suggesting needle trajectories into it.
A new study offers a comparative biopsy yield among three different image-guided biopsy methods:
- Systematic TRUS guided biopsies
- Cognitive fusion guided biopsies
- In-bore real-time MRI guided biopsies.[iii]
Acar et al. (2015) identified 100 patients who were suspected of having prostate cancer based on screening but had no previous biopsy. All patients underwent mpMRI using T2-weighted imaging, diffusion weighted imaging, and dynamic contrast enhanced MRI. They were then assigned to one of three arms for diagnosis, and the men with prostate cancer were treated with radical prostatectomy. Finally, the specimens from surgery were compared with the biopsy findings, and the results are summed up in this table:
| Type of biopsy | Number of patients | Positive diagnosis | Detection of significant cancer identified from RP specimens |
| TRUS guided, systematic | 37 | 51.3% | 69.1% |
| Cognitive fusion | 49 | 55.1% | 70.3% |
| Real time in-bore MRI | 14 | 71.4% | 90% |
In terms of the most accurate biopsy results, mpMRI targeted biopsies offer patients the greatest benefit for the fewest needles. There is a benefit to the pathologist, thanks to the “direct hit” of the needles, because targeted biopsy needles have the best probability of containing any significant cancer that lurks at the tumor’s core. Finally, there is benefit to the patient’s doctor who can discuss the nature of the patient’s disease and the most appropriate treatment choices. Though the study is small, it shows how mpMRI is the most advantageous guidance for prostate biopsy.
NOTE: This content is solely for purposes of information and does not substitute for diagnostic or medical advice. Talk to your doctor if you are experiencing pelvic pain, or have any other health concerns or questions of a personal medical nature.
References
[i] D’Agostino D, Romagnoli D, Giampaoli M, Bianchi FM et al. “In-Bore” MRI-Guided Prostate Biopsy for Prostate Cancer Diagnosis: Results from 140 Consecutive Patients. Curr Urol. 2020 Mar;14(1):22-31.
[ii] Gurgitano M, Ancona E, Maresca D, Summers PE et al. In-bore MRI targeted biopsy. Acta Biomed. 2020 Sep 23;91(10-S):e2020012.
[iii] Acar Ö, Esen T, Çolako?lu B et al. Multiparametric MRI guidance in first-time prostate biopsies: what is the real benefit? Diagn Interv Radiol. 2015 May 29. doi: 10.5152/dir.2015.46014. [Epub ahead of print]
About Dr. Dan Sperling
Dan Sperling, MD, DABR, is a board certified radiologist who is globally recognized as a leader in multiparametric MRI for the detection and diagnosis of a range of disease conditions. As Medical Director of the Sperling Prostate Center, Sperling Medical Group and Sperling Neurosurgery Associates, he and his team are on the leading edge of significant change in medical practice. He is the co-author of the new patient book Redefining Prostate Cancer, and is a contributing author on over 25 published studies. For more information, contact the Sperling Prostate Center.
