CLO22-078: Dual-Tracer PET/CT-Targeted, mpMRI-Targeted, Systematic Biopsy, and Combined Biopsy for the Diagnosis of Prostate Cancer

Authors: Dong-Xu Qiu MD1, Jian Li PhD1, Jin-Wei Zhang BA1, Min-Feng Chen PhD1, Xiao-Mei Gao PhD1, Yong-Xiang Tang PhD1, Ye Zhang PhD1, Xiao-Ping Yi PhD1, Hong-ling Yin PhD1, Yu Gan PhD1, Gui-Lin Wang PhD1, Xiong-Bing Zu PhD1, Shuo Hu PhD1, and Yi Cai PhD1
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  • 1 National Clinical Research Center for Geriatric Disorders, Xiangya Hospital, Central South University, Changsha City, 410008, Hunan Province, P.R. China.

INTRODUCTION AND OBJECTIVE: Growing evidence proved the efficacy of multiparametric MRI (mpMRI) and prostate-specific membrane antigen (PSMA) positron emission tomography/computed tomography (PET/CT)-guided targeted biopsy (TB) in prostate cancer (PCa) diagnosis, but there is no direct comparison between mpMRI-TB and PSMA PET/CT-TB. Gastrin-releasing peptide receptor (GRPR) highly expressed in PCa, which can compensate for the unstable expression of PSMA in PCa. Therefore, we designed a study to compare the efficiency of mpMRI-TB, dual-Tracer (GRPR and PSMA) PET/CT-TB, systematic biopsy, and combined biopsy for the diagnosis of prostate cancer. METHODS: 112 suspicious PCa patients were enrolled from September 2020 and June 2021 in this prospective and comparative effectiveness study. Patients with positive dual-tracer PET/CT or mpMRI results underwent TB and all enrolled patients underwent SB after TB. The primary outcome was the detection rates of PCa in different biopsy strategies. Secondary outcomes were the performance of three imaging methods, omission diagnostic rates, and upgrading and downgrading of biopsy samples relative to those of prostatectomy specimens in different biopsy strategies. RESULTS: In 112 men, clinically significant PCa (grade group≥2) accounted for 34.82% (39/112) and nonclinically significant PCa (grade group =1) accounted for 4.46% (5/112). 68Ga-PSMA PET/CT-TB achieved higher PCa detection rate (69.77%) and positive ratio of biopsy cores (0.44) compared with SB (39.29% and 0.12) and mpMRI-TB (36.14% and 0.23), respectively (P <0.005). Dual-tracer PET/CT as a triage test avoided 52.67% (59/112) unnecessary biopsy, whereas dual-tracer PET/CT-TB plus SB achieved high detection rate (77.36%) without misdiagnosis of csPCa. CONCLUSIONS: Dual-tracer PET/CT could screen patients for avoiding unnecessary biopsy. Dual-tracer PET/CT-TB plus SB might be a more effective and promising strategy for definite diagnosis of clinically significant PCa than mpMRI-TB.

CLO22-078 Table 1. Baseline characteristics.

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* Tumor stage is reported as the clinical stage in the biopsy cohorts.

IQR= interquartile range; PSA= prostate-specific antigen; mpMRI= multi-parametric magnetic resonance imaging; PSMA= prostate-specific membrane antigen; GRPR= gastrin releasing peptide receptor; PET/CT= positron emission tomography/computed tomography.

CLO22-078 Table 2. Detection rate, omission diagnostic rate and biopsy core analysis of different biopsy strategies

T2

TB= targeted biopsy; SB= systematic biopsy; mpMRI= multi-parametric magnetic resonance imaging; PSMA= prostate-specific membrane antigen; GRPR= gastrin releasing peptide receptor; PET/CT= positron emission tomography/computed tomography; PCa= prostate cancer; csPCa= clinically significant prostate cancers; ncsPCa= nonclinically significant prostate cancers; GG: grade group.

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CLO22-078 Figure 1

Citation: Journal of the National Comprehensive Cancer Network 20, 3.5; 10.6004/jnccn.2021.7129

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CLO22-078 Figure 2

Citation: Journal of the National Comprehensive Cancer Network 20, 3.5; 10.6004/jnccn.2021.7129

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CLO22-078 Figure 3

Citation: Journal of the National Comprehensive Cancer Network 20, 3.5; 10.6004/jnccn.2021.7129

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CLO22-078 Figure 4

Citation: Journal of the National Comprehensive Cancer Network 20, 3.5; 10.6004/jnccn.2021.7129

Corresponding Author: Yi Cai, PhD