Background and aim

Gallium-68 (68Ga)-Prostate Membrane Specific Antigen Positron Emission Tomography/Computed Tomography (68Ga-PSMA PET/CT) is an emerging diagnostic modality which is gaining importance in individualized prostate cancer (PCa) management era. This study aimed to investigate the diagnostic accuracy of ⁶⁸Ga-PSMA PET/CT on primary LN staging before radical prostatectomy (RP) in intermediate and high risk PCa.

Materials and Methods

The retrospectively documented 49 patients with intermediate and high risk non-metastatic PCa who had ⁶⁸Ga-PSMA PET/CT before RP were enrolled into this study. The histopathology of dissected LNs was used as reference standard to evaluate the accuracy of ⁶⁸Ga-PSMA PET/CT on primary LN staging, both in per-patient (n = 49) and in per-node (n = 454) analyses. The diagnostic accuracy was investigated using sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV), and by area under the curve (AUC) provided using receiver operating curve (ROC) analysis.

Results

Median age was 64 (48-79) years and, median and mean PSA values were 10 (1.31–138) ng/ml and 16.2 (±19.8) ng/ml, respectively. 22 (44.9%) and 27 (55.1%) of patients had intermediate and high risk PCa, respectively. A total of 5 (10.2%) patients had histopathologically proven LN metastasis and 3 (60%) of them was detected in ⁶⁸Ga-PSMA PET/CT. In per patient analysis, the sensitivity, specifity, PPV and NPV of ⁶⁸Ga-PSMA PET/CT on primary LN staging were 0.60, 0.96, 0.60 and 0.96, respectively. Among overall 454 LNs, 16 (3.5 %) of them were reported as metastatic in histopathology and, 13 (2.9%) of these metastatic LNs were detected in ⁶⁸Ga-PSMA PET/CT. In per-node analysis, the sensitivity, specificity, PPV and NPV of ⁶⁸Ga-PSMA PET/CT on primary LN staging were 0.82, 0.99, 0.87 and 0.99, respectively. The ROC analyses found AUCs for primary LN staging as 0.777 (95%CI:0.508–1.0) in per patient analysis and, as 0.904 (95%CI:0.790 – 1.0) in per node analysis, respectively.

Conclusion

The use of ⁶⁸Ga-PSMA PET/CT has promising diagnostic accuracy on primary LN staging before RP in intermediate and high risk PCa. However, the efforts should be taken to increase sensitivity of ⁶⁸Ga-PSMA PET/CT in individualized treatment era.

中文翻译：

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68Gallium-prostate 特异性膜抗原正电子发射断层扫描/计算机断层扫描 (68Ga-PSMA PET/CT) 对中高危前列腺癌根治性前列腺切除术前原发淋巴结分期的准确度如何？基于患者和淋巴结分析的研究

背景和目的

镓 68 (68Ga)-前列腺膜特异性抗原正电子发射断层扫描/计算机断层扫描 (68Ga-PSMA PET/CT) 是一种新兴的诊断方式，在个体化前列腺癌 (PCa) 管理时代越来越重要。本研究旨在探讨⁶⁸ Ga-PSMA PET/CT 对中高危前列腺癌根治性前列腺切除术 (RP) 前初级 LN 分期的诊断准确性。

材料和方法

回顾性记录了 49 名中危和高危非转移性 PCa 患者，他们在 RP 前进行了^{68 次}Ga-PSMA PET/CT，这些患者被纳入本研究。解剖的 LN 的组织病理学被用作参考标准，以评估⁶⁸ Ga-PSMA PET/CT 对初级 LN 分期的准确性，无论是在每个患者 ( n  = 49) 还是在每个节点 ( n  = 454) 分析中。使用敏感性、特异性、阳性预测值 (PPV) 和阴性预测值 (NPV) 以及使用接受者操作曲线 (ROC) 分析提供的曲线下面积 (AUC) 来研究诊断准确性。

结果

中位年龄为 64 (48-79) 岁，中位和平均 PSA 值分别为 10 (1.31-138) ng/ml 和 16.2 (±19.8) ng/ml。分别有 22 名 (44.9%) 和 27 名 (55.1%) 的患者患有中危和高危 PCa。共有 5 名 (10.2%) 患者经组织病理学证实有 LN 转移，其中 3 名 (60%) 在⁶⁸ Ga-PSMA PET/CT 中检测到。在每位患者分析中，⁶⁸ Ga-PSMA PET/CT 对初级 LN 分期的敏感性、特异性、PPV 和 NPV 分别为 0.60、0.96、0.60 和 0.96。在总共 454 个 LN 中，其中 16 个（3.5%）在组织病理学中被报告为转移性，其中 13 个（2.9%）在⁶⁸个 Ga-PSMA PET/CT 中检测到。在每节点分析中，^{68的敏感性、特异性、PPV 和 NPV}Ga-PSMA PET/CT 对初级 LN 分期分别为 0.82、0.99、0.87 和 0.99。ROC 分析发现，在每个患者分析中，初级 LN 分期的 AUC 分别为 0.777 (95%CI:0.508–1.0)，在每个节点分析中分别为 0.904 (95%CI:0.790–1.0)。

结论

使用⁶⁸ Ga-PSMA PET/CT 在中高风险 PCa 中 RP 前的初级 LN 分期上具有良好的诊断准确性。然而，在个体化治疗时代，应努力提高⁶⁸ Ga-PSMA PET/CT 的敏感性。