MedicalResearch.com Interview with:
Dr. Lars Boesen MD PhD
Department of Urology
MedicalResearch.com: What is the background for this study? What are the main findings?
Response: The current standard of care in prostate cancer diagnosis includes untargeted transrectal ultrasound-guided biopsies for all biopsy-naïve men with clinically suspicion of prostate cancer. However, this strategy that practically has remained unchanged for decades has limited diagnostic accuracy as significant cancers are missed or under-graded and insignificant cancers are unintendedly detected by the random sampling leading to possible overtreatment.
Multiparametric MRI in the diagnosis of prostate cancer has been studied extensively in recent years and has improved detection, localization, staging and risk stratification. It has been suggested that if multiparametric MRIs were used as a triage test prior to biopsies, a significant proportion of men might safely avoid prostate biopsies and the diagnostic ratio of significant vs. insignificant cancer could be improved compared to performing standard biopsies in all men. However, multiparametric MRIs are generally time-consuming (~40 min scan time), expensive and include intravenous contrast media. This reduces its feasibility for widespread clinical implementation in larger patient populations in the western community with its high PCa prevalence.
The development of a simpler and faster (~15 min) biparametric MRI protocol using less scan sequences and circumvents intravenous contrast-media seems to preserve adequate diagnostic accuracy in a detection setting and could facilitate dissemination of prostate MRI as a triage test before any biopsy.
Here we present a large prospective study that assesses the diagnostic accuracy of a novel biparametric MRI to rule out significant prostate cancer in N=1020 biopsy-naive men with clinically suspicion of prostate cancer.
We found that a low suspicion biparametric MRI had a very high negative predictive value (97%) for ruling out significant cancer on confirmatory biopsies. Furthermore, bpMRI suspicion scores were strongly associated with prostate cancer detection rates and restricting biopsies (targeted plus standard) to men with suspicious biparametric MRIs meant 30% could avoid prostate biopsies, improved significant prostate cancer diagnosis by 11%, and reduced insignificant prostate cancer diagnosis by 40% compared to our current diagnostic approach – standard biopsies for all men with clinically suspicion of prostate cancer. Continue reading