Presentation Authors: Yoh Matsuoka*, Sho Uehara, Soichiro Yoshida, Kenji Tanabe, Hiroshi Tanaka, Tomo Kimura, Shingo Moriyama, Yosuke Yasuda, Toshiki Kijima, Minato Yokoyama, Junichiro Ishioka, Kazutaka Saito, Yasuhisa Fujii, Tokyo, Japan
Introduction: Systematic biopsy (SB) has been widely performed as the standard of care concurrently with MRI-targeted biopsy (TB) for prostate cancer (PC) diagnosis although several studies have shown that TB has similar or higher detection rates of significant cancer (SC) than SB. The aim is to clarify who benefits additionally from concurrent SB in SC detection.
Methods: Between Jun 2017 and Oct 2018, 194 consecutive patients with a clinical suspicion of PC who underwent 3T multiparametric MRI followed by TB and 12-core SB using an MRI-ultrasound fusion system (UroNav, Invivo) were enrolled. MRI was centrally assessed using PIRADS v2. Men without PIRADS â‰¥3 lesions were excluded. In TB, a maximum of 3 suspicious regions of interest (ROI) were chosen as targets and 3 cores were taken for each target. The index target was defined as a lesion with the highest PIRADS score (iPIRADS). SC was defined as cancer with ISUP grade group â‰¥2 and/or maximum cancer length >5 mm. According to iPIRADS, detection rates of SC on TB and SB were investigated. Spatial relations between target sites and SB sampling sites were analyzed using 3-D image processing and segmentation software (DynaCAD, Invivo).
Results: In total, iPIRADS â‰¥3 was identified in 171 men (iPIRADS 3/4/5 = 43/59/69). Median lesion volume of each iPIRADS was 0.28/0.35/1.18 ml (p=0.004 for score 4 vs. 5). Overall, TB (median 6 cores per patient), SB, and their combination detected SC in 99 (58%), 81 (47%), and 114 men (67%), respectively (p=0.05 for TB vs. SB). In 15 men (9%), SC was detected by SB but not by TB. In each score of iPIRADS 3/4/5, SC was detected by TB in 9/32/58 men (21/54/84%), by the combination biopsy in 10/42/62 men (23/71/90%), and by SB only in 1/10/4 men (2/17/6%) (p=0.02 for score 3 vs. 4; p=0.04 for score 4 vs. 5). Stereological analyses of the 15 men with SC detected by SB only revealed that SC cores of SB were sampled incidentally from ROIs of TB in 6 men and from outside the ROIs in the other 9 men (iPIRADS 3/4/5 = 0/8/1 men [0/14/1%]) (p=0.01 for score 3 vs. 4; p=0.01 for score 4 vs. 5).
Conclusions: A majority of SC (87% [99/114]) detected by the combination biopsy is detectable by TB alone. However, men with iPIRADS 4 lesions acquire larger benefits from concurrent SB because more SC outside the ROI of TB is detected by SB compared to the other scores.