An update on primary prostate cancer imaging

( At the annual meeting of the Society of Urologic Oncology (SUO), Dr. James Wysock an update on primary prostate cancer imaging. Dr. Wysock briefly discussed imaging strategies in both the screening and diagnosis of localized prostate cancer.

The poor sensitivity and specificity in the screening and diagnosis of men with prostate cancer is a known limitation of our current technologies. Prostate-specific antigen (PSA0-targeted screening and transrectal ultrasound (TRUS) guided biopsies lead to both under-sampling of clinically significant prostate cancer and overdetection of indolent prostate cancer. As a result, there is an increasing interest in the use of MRI and MRI-targeted biopsies. To address this diagnostic gap, Dr. Wysock presents data from Kim et al. demonstrating the rapidly increasing use of prostate MRI in recent years, reflecting this growing dependence on MRI-guided biopsies (Figure 1).


Dr. Wysock presented data from two groundbreaking studies assessing the usefulness of MRI-guided biopsies for cancer detection: the PROMIS, Diagnostic accuracy of multi-parametric MRI and TRUS biopsy in prostate cancer (PROMIS), and PRECISION, MRI-Targeted Versus Standard Biopsy in Prostate Cancer Diagnosis: (The PRECISION Trial).

In the PROMIS study, men underwent both an MRI-guided biopsy and TRUS-guided biopsy, which was then compared to the standard of a transperineal mapping biopsy.1. The authors noted that MRI-guided biopsies were more sensitive to the detection of clinically significant prostate cancer than TRUS-guided biopsies alone. In the PRECISION study, men were randomized to either standard TRUS-guided biopsy or an MRI-targeting strategy, with men undergoing a targeted biopsy if the prostate MRI was of concern for prostate cancer2. More men randomized to MRI were found to have clinically significant prostate cancer compared to men who underwent TRUS-guided biopsy (38% and 26%, respectively). In addition, men randomized to the MRI arm were less likely to have biopsies identifying a clinically insignificant disease compared to men in the TRUS-guided biopsy arm. Importantly, about 20% of the men randomized to the MRI arm completely avoided a biopsy because of reassuring MRI findings. These studies suggest that MRI stratified biopsy strategies are superior in detecting clinically significant prostate cancer, while minimizing the detection of clinically insignificant disease.

Dr. Wysock highlighted some limitations of MRI and MRI-targeted biopsies and presented data from Sonn et al. Showing significant inter-observer variability between radiologists reading prostate MRIs, assigning PIRADS scores, and subsequent detection of clinically significant cancers3. Hopefully, with standardization and improvement in familiarity with MRI and MRI guided biopsies, the variability will decrease between radiologists assigning PIRADS scores and corresponding cancer detection on targeted biopsies, further enhancing the usability of these technologies.

Dr. Wysock briefly discusses the role of MRI as a potential screening tool for prostate cancer, where MRI could function in the future similar to mammography for breast cancer or a low-dose CT scan for lung cancer, two cancers whose screening programs rely heavily on imaging modalities. Additionally, 29 MHz high-resolution micro-ultrasound is an emerging technology that may play a role in the screening and detection of clinically significant prostate cancer in the future, although these data are not yet mature.

Delivery MRI and other improved imaging technologies show significant promise and improved accuracy compared to the status quo in nearly all states of prostate cancer care, including the screening, detection, staging and monitoring of men with prostate cancer. This author eagerly awaits further studies that integrate these technologies into prostate cancer screening, detection, and treatment paradigms.

Presentation: Dr. James Wysock, MD, MSc. Urological Oncologist, NYU Langone Health, New York, New York, United States.

Written by: Kevin Ginsburg, MD, and Adrien Bernstein, MD, Society of Urologic Oncology Fellow, Fox Chase Cancer Center, Fox Chase Cancer Center, Philadelphia, PA, at the 2020 Society of Urologic Oncology Annual Meeting – December 2-5, 2020 – Washington, DC

1. Ahmed, HU, El-Shater Bosaily, A., Brown, LC, et al .; Diagnostic accuracy of multi-parametric MRI and TRUS biopsy in prostate cancer (PROMIS): a paired validating confirmatory study. Lancet, 389:815, 201
2. Kasivisvanathan, V., Rannikko, AS, Borghi, M. et al .; MRI targeted or standard biopsy for prostate cancer diagnosis. N Engl J Med, 378: 1767, 2018
3. Sonn, GA, Fan, RE, Ghanouni, P. et al .; Prostate Magnetic Resonance Imaging Interpretation varies considerably between radiologists. Eur Urol Focus, 5: 592, 2019

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