BERKELEY, CA (UroToday.com) - For this review article, all possible imaging tools for prostate cancer were considered, including MRI and all ultrasound-based imaging tools. Only studies comparing the detection rates of targeted biopsies over systematic biopsies in a controlled fashion and in an appropriate patient cohort were included. Basically only two different study designs fulfilled these criteria of a “well designed” study. In the first study design, targeted and systematic biopsies were performed in the same patient, during the same session, with separate analyses of the detection rate based on targeted cores and on systematic cores. In such studies, each patient served as his own control, and selection biases could be excluded. Ideally the targeted and the systematic cores were taken by two different operators, with the second operator blinded for the location of suspicious lesions based on imaging. This should avoid, during systematic biopsy, the operator intentionally aiming for or avoiding suspicious lesions found in imaging. Both would substantially bias the results in favor of or against one of the biopsy approaches. Of note, not all studies respected this detail and targeted and systematic cores were actually taken by the same operator.
In the second study design, a randomized approach was used placing patients into two groups. One group combined image-targeted and systematic biopsies, and the second group received only systematic biopsies without the use of targeted biopsies. By comparing the prostate cancer detection rates between the groups, the effect of targeted biopsies could be estimated. The randomized approach should also exclude selection biases in favor of one of the approaches. Ideally, in both groups, the same number of cores are taken, therefore replacing the systematic cores by targeted cores in a systematic biopsy scheme. Of note, not all studies respected these criteria and several performed targeted cores in addition to the systematic cores, which resulted in a higher number of cores in the first group relative to the second group. Such imbalance might explain, to a certain extent, a difference in the detection rates.
Moreover, we analyzed only studies including patients without diagnosis of prostate cancer, either in the initial biopsy setting or the repeat biopsy setting. Also, we intentionally excluded the following studies:
- Matched or historic patient cohorts for comparison, as here no controlled design is provided and a major selection bias cannot be ruled out
- No detection rates reported separately for the image-targeted approach or the systematic approach
- No detection rate reported in a per patient analysis (only the per core detection rates reported)
We separately reported the performance of image-targeted biopsies over systematic biopsies for each imaging approach, elastography, contrast enhanced ultrasound, histoscanning, and MRI. The article provides detailed tables addressing the outcome regarding number randomized and targeted cores, detection rate by patients, detection rates per core, length of cancer by core, and significance of cancer detected.
Written by:
Jochen Walz 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, Institut Paoli-Calmettes Cancer Centre, 232, Boulevard Ste. Marguerite, BP 156, 13273, Marseille, France
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