Reply to Editorial Comment: A Variable Length Biopsy Device Designed for Improved Prostate Cancer Detection vs the Standard Biopsy Device: Pathological Comparisons and Needle Length Requirements for Men Undergoing Transperineal Biopsy

The authors appreciate the comments of Ng and Ranasinghe1 and agree that clinical studies are needed to confirm that longer tissue specimens can improve risk stratification for active surveillance, focal ablation, surgery, and radiation therapy. The gold standard for multiparametric MRI accuracy is not systematic plus targeted biopsies but, as described by Johnson et al,2 comparison with prostatectomy specimens. In this regard, MRI, while improving identification of men with clinically significant prostate cancer (csPCa) and decreasing unnecessary biopsies, often fails to identify contralateral high-grade disease. Stone et al has shown that MRI has an AUC of only 53.8% (for csPCa) when compared with a thorough mapping biopsy. Longer specimens could potentially reduce the number of mapping biopsies (median of 62.5) by 50% to 75% and make systematic biopsies more informative.3 MRI also underestimates lesion size. As suggested by Ng and Ranasinghe, perilesional sampling can help to mitigate the inaccuracy in lesion margin identification, but lesion length should also be determined. A biopsy that spans the prostate from apex to base will identify the z plane dimension of the tumor further enhancing planning of a partial ablation approach. Finally, improved quantification of grade 4 disease with more robust tissue samples, which helps predict disease extent in prostatectomy specimens, is necessary to properly inform patients of treatment failure risks for any given therapy.4 Hopefully, these and potential morbidity concerns can be addressed with patient-centered investigations.5