Shear wave elastography for localization of prostate cancer lesions and assessment of elasticity thresholds: Implications for targeted biopsies and active surveillance protocols - Abstract

INTRODUCTION: Shear wave elastography (SWE) allows cancer detection by using focused ultrasound pulses for locally deforming tissue.

These differences in tissue elasticity and stiffness are increasingly used in breast cancer imaging and also help detect potential tumor lesions within the prostate.

AIM: Of this study was to localize prostate cancer lesions by using SWE prior to radical prostatectomy (RP) and to assess examiner independent elasticity threshold for cancer foci detection.

PATIENTS AND METHODS: In 60 consecutive high-, intermediate- and low-risk patients, SWE scanning of the whole prostate was performed prior to RP. Localization of suspect lesions and density threshold (kPa) were recorded in up to twelve areas and resulted in 703 different fields. SWE findings were correlated with final pathology. Initially, 381 areas were used for establishing SWE cut-offs (development cohort n=32). Subsequently, these cut-offs were validated in 322 areas (validation cohort n=28).

RESULTS: Significant differences were recorded for SWE-elasticity of benign tissue vs. prostate cancer nodules: 42 kPa (29-71.3) vs. 88 kPa (54-123) (all p< 0.001). Median diameter of cancer lesions was 26 mm (18-41mm). Applying the most informative cut-off of 50 kPa to the validation cohort resulted in an 80.9 and 69.1 sensitivity and specificity with an accuracy of 74.2 for detecting cancer nodules based on final pathological finding; corresponding positive and negative predictive values were 67.1 and 82.2 %.

CONCLUSIONS: SWE allows identifying cancer foci based on SWE differences. Moreover, reliable cut-offs for this approach can be established, allowing an examiner independent localization of prostate cancer foci.

Written by:
Boehm K, Salomon G, Beyer B, Schiffmann J, Simonis K, Graefen M, Budaeus L.   Are you the author?
Martini Clinic, Prostate Cancer Center at University Hospital Hamburg-Eppendorf, Hamburg, Germany; Department of Urology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany.  

Reference: J Urol. 2014 Sep 25. pii: S0022-5347(14)04574-1.
doi: 10.1016/j.juro.2014.09.100

PubMed Abstract
PMID: 25264337 Prostate Cancer Section