This study aimed to assess the diagnostic value of [¹⁸F]AlF-thretide PET/CT in patients with newly diagnosed prostate cancer (PCa). Methods: In total, 49 patients with biopsy-proven PCa were enrolled in this prospective study. All patients underwent [¹⁸F]AlF-thretide PET/CT, and the scoring system of the PRIMARY trial was used for PET image analysis. The dosimetry evaluation of [¹⁸F]AlF-thretide was performed on 3 patients. Pathologic examination was used as the reference standard to evaluate the location, number, size, and Gleason score of tumors, for comparison with the [¹⁸F]AlF-thretide PET/CT results. PSMA expression was evaluated by immunohistochemical staining. Results: All patients tolerated the [¹⁸F]AlF-thretide PET/CT well. The total effective dose of [¹⁸F]AlF-thretide was 1.16E−02 mSv/MBq. For patient-based analysis of intraprostatic tumors, 46 of 49 (93.9%) patients showed pathologic uptake on [¹⁸F]AlF-thretide PET/CT. For lesion-based analysis of intraprostatic tumors, the sensitivity and positive predictive value for [¹⁸F]AlF-thretide PET/CT were 58.2% and 90.5%, respectively. Delayed images can detect more lesions than standard images (n = 57 vs. 49, P = 0.005), and the SUV_max and tumor-to-background ratio of the former were higher than those of the latter (SUV_max: 14.5 ± 16.7 vs. 11.4 ± 13.6, P < 0.001; tumor-to-background ratio: 37.1 ± 42.3 vs. 23.1 ± 27.4, P < 0.001). The receiver-operating-characteristic curve analysis showed that the areas under the curve for PRIMARY score–predicted true-positive and false-positive lesions were significantly higher than those for the SUV_max of standard images (P = 0.015) and seemed higher than those for the SUV_max of delayed images (P = 0.257). [¹⁸F]AlF-thretide PET/CT showed a higher detection rate than multiparametric MRI for all intraprostatic foci (53.5% vs. 40.8%, P = 0.012) and clinically significant PCa (75.0% vs. 61.4%, P = 0.031). Conclusion: [¹⁸F]AlF-thretide PET/CT showed high diagnostic value for patients with primary PCa and can be used as an excellent imaging modality for preoperative evaluation of PCa patients.

^{本研究旨在评估[ 18} F]AlF-thretide PET/CT 对新诊断的前列腺癌（PCa）患者的诊断价值。方法：总共 49 名经活检证实患有 PCa 的患者参与了这项前瞻性研究。所有患者均接受[ ¹⁸ F]AlF-thretide PET/CT，并采用PRIMARY试验的评分系统进行PET图像分析。对3名患者进行了[ ¹⁸ F]AlF-thretide的剂量测定评估。以病理检查为参考标准，评价肿瘤的位置、数量、大小及Gleason评分，并与[ ¹⁸ F]AlF-thretide PET/CT结果进行比较。通过免疫组织化学染色评估 PSMA 表达。结果：所有患者对[ ¹⁸ F]AlF-thretide PET/CT 的耐受性良好。 [ ¹⁸ F]AlF-thretide的总有效剂量为1.16E−02 mSv/MBq。对于前列腺内肿瘤的基于患者的分析，49 名患者中的 46 名 (93.9%) 在 [ ¹⁸ F]AlF-thretide PET/CT 上显示出病理摄取。对于前列腺内肿瘤的基于病变的分析，[ ¹⁸ F]AlF-thretide PET/CT的敏感性和阳性预测值分别为58.2%和90.5%。延迟图像比标准图像能够检测到更多的病灶（n = 57 vs. 49，P = 0.005），并且前者的 SUV _max和肿瘤背景比均高于后者（SUV _max： 14.5 ± 16.7）对比 11.4 ± 13.6，P < 0.001；肿瘤与背景比：37.1 ± 42.3 对比 23.1 ± 27.4，P < 0.001）。接受者操作特征曲线分析显示，PRIMARY评分预测的真阳性和假阳性病变的曲线下面积显着高于标准图像SUV _max的曲线下面积（P = 0.015），并且似乎高于标准图像的SUV max延迟图像的SUV_最大值( P = 0.257)。 [ ^{18 F]AlF-thretide PET/CT 对所有前列腺内病灶（53.5% vs. 40.8%，} P = 0.012）和有临床意义的 PCa（75.0% vs. 61.4%，P = 0.031）的检出率均高于多参数 MRI 。结论： [ ¹⁸ F]AlF-thretide PET/CT对原发性PCa患者具有较高的诊断价值，可作为PCa患者术前评估的良好影像学手段。