Delayed PSMA PET/CT Imaging for Diagnosing Clinically Significant Prostate Cancer in Biopsy-Naïve Men With Suspected Prostate Cancer
试验速览
- 阶段
- 不适用
- 状态
- 招募中
- 发起方
- 入组人数
- 1,000
- 试验地点
- 9
- 主要终点
- Area Under the Curve (AUC) of Delayed SUVmax vs. Standard SUVmax for csPCa
研究概览
简要总结
Brief Summary This prospective, multicenter study evaluates whether delayed PSMA PET imaging improves diagnostic efficacy for detecting clinically significant prostate cancer (Gleason score ≥7) compared with standard imaging in patients with suspected newly diagnosed prostate cancer. Each patient serves as their own control, with diagnostic performance compared between standard (60-minute) and delayed (2-3 hour) acquisitions.
Background PSMA PET has transformed prostate cancer imaging, with emerging evidence suggesting delayed acquisition may further improve diagnostic accuracy by increasing tumor-to-background ratio. Recent studies demonstrate that delayed imaging significantly reduces equivocal findings and enhances detection of clinically significant prostate cancer.
Need While standard PSMA PET is well-validated, prospective multicenter data specifically evaluating the incremental diagnostic value of delayed imaging for clinically significant prostate cancer in treatment-naïve patients are lacking. This study addresses this gap by systematically comparing standard and delayed imaging in a large, well-defined cohort.
Primary Outcome The primary outcome is to compare the area under the curve (AUC) of delayed SUVmax versus standard SUVmax for detecting clinically significant prostate cancer (csPCa), and to determine whether delayed imaging is superior to standard imaging.
Secondary Outcomes
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Optimal diagnostic thresholds for delayed imaging
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Determine the optimal threshold for delayed SUVmax using ROC analysis with the Youden index;
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Determine the optimal threshold for ΔSUVmax (delayed minus standard SUVmax);
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Validate the sensitivity, specificity, and AUC of these thresholds in an independent validation set.
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Biopsy avoidance potential In patients with PI RADS 4-5 lesions, calculate the negative predictive value (NPV) using a predefined high threshold to estimate the proportion who could safely avoid biopsy.
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Diagnostic performance in key subgroups Compare the AUC of delayed SUVmax versus standard SUVmax for csPCa detection in patients with PI RADS 2-3 and in those with PI RADS 4-5.
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Additional lesion detection Proportion of patients with additional csPCa lesions detected only on delayed imaging, and the proportion whose PI RADS category would be upgraded based on these findings.
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Clinical decision impact Proportion of patients in whom management recommendations would change after incorporating delayed imaging results, compared with standard imaging alone.
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Exploratory subgroup analyses Stratify by PSA level (<4, 4 10, >10 ng/mL) and PSA density (<0.10, 0.10-0.20, >0.20 ng/mL/cc) to identify subgroups that derive the greatest benefit from delayed imaging; additionally, explore combined subgroups such as PI RADS 3 with PSA 4-10 or PSAD 0.10-0.20.
Inclusion Criteria
- Suspected prostate cancer based on elevated PSA (≥4.0 ng/mL) or clinical symptoms
- Undergo PSMA PET (standard + delayed) prior to prostate biopsy
- Willing to undergo prostate biopsy
- Provide written informed consent Exclusion Criteria
1. Prior prostate cancer treatment before PSMA PET imaging 2. Other malignancy within past two years 3. Investigator-judged risk of serious complications interfering with study conduct
详细描述
Study Design and Objective This is a prospective, multicenter diagnostic accuracy study designed to evaluate whether delayed PSMA PET imaging improves diagnostic efficacy for clinically significant prostate cancer (csPCa) compared with standard imaging in patients with suspected newly diagnosed, treatment-naïve prostate cancer. Each patient serves as their own control.
Imaging Protocol
All enrolled patients undergo dual-time-point PSMA PET/CT before biopsy:
- Standard acquisition: whole-body imaging at approximately 60 minutes post-injection.
- Delayed acquisition: pelvic-focused imaging at 2-3 hours post-injection.
Reference Standard All patients undergo prostate biopsy using 12-core systematic biopsy plus targeted biopsy when indicated. Histopathology serves as the reference standard. csPCa is defined as ISUP grade group ≥2.
研究设计
- 研究类型
- Observational
- 观察模型
- Case Crossover
- 时间视角
- Prospective
入排标准
- 年龄范围
- 18 Years 至 —（Adult, Older Adult）
- 性别
- Male
- 接受健康志愿者
- 否
入选标准
- •Patients with suspected prostate cancer and a PSA level ≥4.0 ng/mL
- •Patients who undergo PSMA PET imaging (including delayed phase imaging) prior to prostate biopsy
- •Patients who are willing to undergo prostate biopsy
- •Patients who provide written informed consent to participate in the study
排除标准
- •Patients who have received any prior prostate cancer-related treatment before the initial PSMA PET scan
- •Patients with a history of other malignancies within the past two years
- •Patients judged by the study investigator to be at risk for serious complications that could interfere with the normal conduct of the study
研究组 & 干预措施
Study Cohort
All enrolled patients with suspected prostate cancer undergo both standard and delayed PSMA PET imaging. Each patient serves as their own control, with diagnostic performance compared between the standard imaging phase and the delayed imaging phase.
干预措施: [⁶⁸Ga]Ga-PSMA PET/CT with Delayed Pelvic PET-Only Acquisition (Diagnostic Test)
结局指标
主要结局
Area Under the Curve (AUC) of Delayed SUVmax vs. Standard SUVmax for csPCa
时间窗: [Time Frame: Baseline (comparison of standard vs. delayed images)]
Compare the AUC of delayed SUVmax versus standard SUVmax for detecting clinically significant prostate cancer (ISUP grade group ≥2) using the DeLong test , to determine whether delayed imaging is superior.
次要结局
- Optimal Threshold of Delayed SUVmax for csPCa(Baseline)
- Optimal Threshold of ΔSUVmax (Delayed Minus Standard) for csPCa(Baseline)
- Diagnostic Performance of Optimal Thresholds in Validation Cohort(Baseline)
- Negative Predictive Value for Biopsy Avoidance in PI-RADS 4-5 Patients(Baseline)
- AUC of Delayed vs. Standard Imaging in PI-RADS 2-3 and PI-RADS 4-5 Subgroups(Baseline)
- Proportion of Patients with Additional csPCa Lesions Detected Only on Delayed Imaging(Baseline)
- Proportion of Patients with Change in Clinical Management After Delayed Imaging ( Exploratory)(Baseline)
- Exploratory Subgroup Analyses by PSA and PSAD(Baseline)
- Inter-Observer Agreement for SUVmax Measurement of the Most Suspicious Intraprostatic Lesion on Standard and Delayed PSMA PET/CT (Intraclass Correlation Coefficient, ICC, Exploratory)(Baseline)