From the Departments of *Nuclear Medicine, †Medical Physics and Radiation Protection, ‡Urology and Urological Oncology, and §Radiation and Special Oncology, Hannover Medical School, Hannover; and ∥Department of Pharmaceutical Radiochemistry, Technical University Munich, Munich, Germany.
Clin Nucl Med. 2017 Jun;42(6):e286-e293. doi: 10.1097/RLU.0000000000001589.
The aims of this study were to gain mechanistic insights into prostate cancer biology using dynamic imaging and to evaluate the usefulness of multiple time-point Ga-prostate-specific membrane antigen (PSMA) I&T PET/CT for the assessment of primary prostate cancer before prostatectomy.
Twenty patients with prostate cancer underwent Ga-PSMA I&T PET/CT before prostatectomy. The PET protocol consisted of early dynamic pelvic imaging, followed by static scans at 60 and 180 minutes postinjection (p.i.). SUVs, time-activity curves, quantitative analysis based on a 2-tissue compartment model, Patlak analysis, histopathology, and Gleason grading were compared between prostate cancer and benign prostate gland.
Primary tumors were identified on both early dynamic and delayed imaging in 95% of patients. Tracer uptake was significantly higher in prostate cancer compared with benign prostate tissue at any time point (P ≤ 0.0003) and increased over time. Consequently, the tumor-to-nontumor ratio within the prostate gland improved over time (2.8 at 10 minutes vs 17.1 at 180 minutes p.i.). Tracer uptake at both 60 and 180 minutes p.i. was significantly higher in patients with higher Gleason scores (P < 0.01). The influx rate (Ki) was higher in prostate cancer than in reference prostate gland (0.055 [r = 0.998] vs 0.017 [r = 0.996]).
Primary prostate cancer is readily identified on early dynamic and static delayed Ga-PSMA ligand PET images. The tumor-to-nontumor ratio in the prostate gland improves over time, supporting a role of delayed imaging for optimal visualization of prostate cancer.
本研究旨在通过动态成像获得前列腺癌生物学的机制见解，并评估多次时间点 Ga-前列腺特异性膜抗原（PSMA）I&T PET/CT 在前列腺癌患者前列腺切除术之前评估原发性前列腺癌的效用。
20 例前列腺癌患者在前列腺切除术前行 Ga-PSMA I&T PET/CT 检查。PET 方案包括早期盆腔动态成像，然后在注射后 60 分钟和 180 分钟进行静态扫描。SUV、时间-活性曲线、基于 2 组织隔室模型的定量分析、Patlak 分析、组织病理学和 Gleason 分级在前列腺癌与良性前列腺组织之间进行了比较。
95%的患者在早期动态和延迟成像上均能识别出原发性肿瘤。与良性前列腺组织相比，在任何时间点（P ≤ 0.0003），前列腺癌的摄取均显著更高，并随时间增加。因此，前列腺内肿瘤与非肿瘤的比值随时间推移而改善（注射后 10 分钟为 2.8，180 分钟为 17.1）。在 Gleason 评分较高的患者中，注射后 60 分钟和 180 分钟的摄取均显著更高（P < 0.01）。前列腺癌的流入率（Ki）高于参考前列腺（0.055[r = 0.998] vs 0.017[r = 0.996]）。
早期动态和静态延迟 Ga-PSMA 配体 PET 图像上可轻易识别原发性前列腺癌。前列腺内肿瘤与非肿瘤的比值随时间推移而改善，支持延迟成像对最佳显示前列腺癌的作用。
