(UroToday.com) The 2022 GU ASCO Annual meeting included a prostate cancer session featuring work from Dr. Dong-Xu Qiu and colleagues presenting results assessing dual-tracer PET/CT-targeted, mpMRI-targeted, systematic biopsy, and combined biopsy for the diagnosis of prostate cancer.
Recent evidence has proven the efficacy of multiparametric MRI (mpMRI) and PSMA PET/CT-guided targeted biopsy in prostate cancer diagnosis, but there is no direct comparison between mpMRI-targeted biopsy and PSMA PET/CT-targeted biopsy. Gastrin-releasing peptide receptor (GRPR) is highly expressed in prostate cancer, which can compensate for the unstable expression of PSMA in prostate cancer. Therefore, Dr. Qui and investigators designed a study to compare the efficiency of mpMRI-targeted biopsy, dual-Tracer (GRPR and PSMA) PET/CT-targeted biopsy, systematic biopsy, and combined biopsy for the diagnosis of prostate cancer.
There were 112 patients with suspicion of prostate cancer 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 targeted biopsy and all enrolled patients underwent systematic biopsy after targeted biopsy. The primary outcome was the detection rates of prostate cancer 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.
In 112 men, clinically significant prostate cancer (grade group≥2) accounted for 34.8% (39/112) and non-clinically significant prostate cancer (grade group = 1) accounted for 4.5% (5/112). 68Ga-PSMA PET/CT-targeted biopsy achieved higher prostate cancer detection rate (69.8%) and positive ratio of biopsy cores (0.44) compared with systematic biopsy (39.3% and 0.12) and mpMRI-targeted biopsy (36.1% and 0.23), respectively (p < 0.005). Dual-tracer PET/CT as a triage test avoided 52.7% (59/112) unnecessary biopsy, whereas dual-tracer PET/CT-targeted biopsy plus systematic biopsy achieved a high detection rate (77.4%) without misdiagnosis of clinically significant prostate cancer. The flowchart of recommended prostate biopsy protocol is as follows:
Dr. Qiu concluded this presentation of assessing dual-tracer PET/CT-targeted, mpMRI-targeted, systematic biopsy, and combined biopsy for the diagnosis of prostate cancer with the following concluding statements:
- Dual-tracer PET/CT could screen patients for avoiding unnecessary biopsy
- Dual-tracer PET/CT-targeted biopsy plus systematic biopsy might be a more effective and promising strategy for definite diagnosis of clinically significant prostate cancer than mpMRI-targeted biopsy
Presented by: Dong-Xu Qiu, Department of Urology, National Clinical Research Center for Geriatric Disorders, Xiangya Hospital, Central South University, Changsha, China
Co-Authors: Jian Li, Jinwei Zhang, Minfeng Chen, Xiaomei Gao, Yongxiang Tang, Ye Zhang, Xiaoping Yi, Hongling Yin, Yu Gan, Guilin Wang, Xiongbing Zu, Shuo Hu, Yi Cai
Written by: Zachary Klaassen, MD, MSc – Urologic Oncologist, Assistant Professor of Urology, Georgia Cancer Center, Augusta University/Medical College of Georgia, @zklaassen_md on Twitter during the 2022 American Society of Clinical Oncology Genitourinary (ASCO GU) Cancers Symposium, Thursday, Feb 17 – Saturday, Feb 19, 2022