Biopsy strategies for selecting patients for focal therapy for prostate cancer

Abstract

Focal therapy for localised prostate cancer requires accurate disease localization and characterization. Standard trans-rectal ultrasound biopsy can miss significant cancer and cannot accurately localize prostate cancer to guide focal therapy. This article examines various biopsy and imaging strategies to determine which is the most useful in diagnosing prostate cancer suitable for treatment with focal therapy. Advances in MRI and ultrasound have been combined with different biopsy techniques such as transperineal and targeted biopsy versus transrectal and whole-gland sampling to see which method detects and localizes cancer while reducing the burden of biopsy on patients. Studies tended to report on overall cancer detection rates as opposed to clinically significant cancer detection rates. A standard definition of clinically significant cancer must first be defined and validated against an accurate sampling strategy such as radical prostatectomy or transperineal prostate mapping biopsy. Image-guided targeted biopsy has increased detection rates of clinically significant cancer rate with fewer number of cores compared with whole-gland sampling. Further prospective randomized controlled trials are needed to identify a combined image and biopsy technique that detects and localizes the highest rate of clinically significant cancer while decreasing the risk to patients, in order to guide focal therapy.