BERKELEY, CA (UroToday.com) -
We have recently published the results of an interdisciplinary Delphi consensus meeting on the role of multiparametric MRI (mpMRI) of the prostate when used for focal therapy of prostate cancer
Following the discovery of prostate specific antigen (PSA), the incidence of prostate cancer increased drastically, whereas the cancer-specific mortality rate remained unchanged at 5%. Concerns have been raised about the increasing detection of low- and intermediate-risk prostate cancer, since active treatment may not improve disease-related survival but on the other hand may significantly impair quality of life. Consequently, deferred treatment, such as active surveillance or watchful waiting, present appealing management solutions which could improve quality of life. However, these management options have their disadvantages. Focal therapy can offer an active treatment in patients with low- and intermediate-risk prostate cancer, since it offers cancer control without the possible side effects of radical treatments.
State-of-the art imaging in all phases of focal therapy is crucial to enable optimal treatment. In focal therapy, generally 3 phases can be distinguished, each demanding different aspects from imaging modalities.
- Patient selection: Selection of a patient with low- or intermediate-risk prostate cancer (≤T2, Gleason score ≤ 4+3, and PSA < 20 ng/mL), with a target lesion confined to one lobe of the prostate.
- Treatment guidance: Real-time guidance of the focal treatment modality to the targeted lesion.
- Follow-up: Following treatment, demonstration that there is no residual tumour, or after a period of time, there are no recurrent tumours.
Multiparametric (mp)MRI is an imaging technology with high imaging resolution and contrast. This makes it an excellent technology for patient selection and treatment planning and follow-up in focal therapy of prostate cancer. However, the lack of standardization and variations in technique and interpretation of images have fueled debate about its reported performance characteristics.
The goal of the consensus was to define the role of mpMRI in these 3 phases of focal therapy. An online consensus process based on a questionnaire was circulated according to the Delphi method. A face-to-face consensus meeting followed 3 rounds of questions that were sent to a 48-participant expert panel comprised of urologists, radiologists, and engineers. Discussion points were identified by literature search and were sent to the panel by an online questionnaire in 3 rounds. Participants were presented with the results of the previous rounds. Conclusions formulated from the results of the questionnaire were discussed, in detail, in the final face-to-face meeting.
Consensus was reached on 41% of the key items related to the conduct, interpretation, and reporting of mpMRI for use in treatment planning, treatment guidance, and follow-up of focal therapy for prostate cancer. This relatively low level of consensus (41% of the topics) indicates that there are many uncertainties in this field. Through incorporation of the recommendations presented in the paper, the conduct, interpretation, and reporting of mpMRI in treatment planning, treatment guidance, and treatment follow-up of focal therapy will be more consistent and standardized. By pooled analyses, clinical diagnostic accuracy of mpMRI will increase. Future studies comparing mpMRI to transperineal saturation mapping biopsies will confirm the important role of mpMRI in a variety of purposes in focal therapy for prostate cancer. If the accuracy of mpMRI reaches levels to sufficiently rule out significant tumour load, one can speculate about obviating template saturation mapping biopsies in patients undergoing focal therapy in the future.
Written by:
Berrend G. Muller, MD; W. van den Bos MD; Theo M. de Reijke, MD, PhD; and Jean J.M.C.H. de la Rosette, MD, PhD as part of Beyond the Abstract on UroToday.com. This initiative offers a method of publishing for the professional urology community. Authors are given an opportunity to expand on the circumstances, limitations etc... of their research by referencing the published abstract.
Department of Urology, AMC University Hospital, Amsterdam, the Netherlands
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