The smarttarget biopsy trial: a prospective paired blinded trial with randomisation to compare visual-estimation and image-fusion targeted prostate biopsies

INTRODUCTION AND OBJECTIVES: Multi‐parametric MRI targeted prostate biopsies can improve detection of clinically significant prostate cancer and decrease the diagnosis of clinically insignificant cancers. There is debate whether visual estimated targeting is sufficient or whether image‐fusion software is required. We conducted an ethics committee approved, prospective, blinded, paired validating clinical trial of visual estimated targeted biopsies compared to non‐rigid MR/US image‐fusion using an academically developed fusion system (SmartTarget®). METHODS: 141 men requiring targeted transperineal biopsies for accurate risk stratification were enrolled following written informed consent (August2014‐September2016). Entry required prior trans‐rectal ultrasound biopsy, a discrete lesion on mpMRI (PIRADS 3‐5) and no previous prostate cancer treatment. All men underwent a targeted transperineal biopsy of a single lesion using visual estimation (3 cores) and image‐fusion (3 cores). Two different urologists independently conducted the targeting strategies with each urologist assigned a strategy and order by randomised. Only one urologist was permitted to be present for each biopsy strategy and did not communicate with the other about any aspect of the procedure (blinded). 14 urologists of varying levels of experience participated. All were competent in transperineal targeting. UCL definition 2 clinically significant prostate cancer was used as the target condition for the primary outcome (>/= G3+4 and or MCCL >/= 4mm). RESULTS: 129 men completed both biopsy strategies. Median age (IQR) was 65 years (58‐70) and median PSA was 8.5ng/ml (5.6‐ 12.1). 94 (72.8%) had clinically significant prostate cancer; 81/94 (86.2%) were identified on visual estimation targeting and 81/94 (86.2%) on image‐fusion targeting. Fusion biopsy and visual estimation targeting each identified clinically significant cancers that the other missed, 13 and 13 respectively. We found no statistically significant difference between visual estimation and image‐fusion (McNemar, p=1.00). CONCLUSIONS: Our prospective, paired blinded trial demonstrates that there is no overall difference in detection of clinically significant prostate cancer between visual estimation and image‐fusion targeted biopsies. Our results suggest that both techniques should be used together for optimal cancer detection.