The interobserver agreement for ⁶⁸Ga-PSMA-11 PET/CT study interpretations in patients with prostate cancer is unknown. Methods: ⁶⁸Ga-PSMA-11 PET/CT was performed in 50 patients with prostate cancer for biochemical recurrence (n = 25), primary diagnosis (n = 10), biochemical persistence after primary therapy (n = 5), or staging of known metastatic disease (n = 10). Images were reviewed by 16 observers who used a standardized approach for interpretation of local (T), nodal (N), bone (Mb), or visceral (Mc) involvement. Observers were classified as having a low (<30 prior ⁶⁸Ga-PSMA-11 PET/CT studies; n = 5), intermediate (30–300 studies; n = 5), or high level of experience (>300 studies; n = 6). Histopathology (n = 25, 50%), post–external-beam radiation therapy prostate-specific antigen response (n = 15, 30%), or follow-up PET/CT (n = 10, 20%) served as a standard of reference. Observer groups were compared by overall agreement (% patients matching the standard of reference) and Fleiss' κ with mean and corresponding 95% confidence interval (CI). Results: Agreement among all observers was substantial for T (κ = 0.62; 95% CI, 0.59–0.64) and N (κ = 0.74; 95% CI, 0.71–0.76) staging and almost perfect for Mb (κ = 0.88; 95% CI, 0.86–0.91) staging. Level of experience positively correlated with agreement for T (κ = 0.73/0.66/0.50 for high/intermediate/low experience, respectively), N (κ = 0.80/0.76/0.64, respectively), and Mc staging (κ = 0.61/0.46/0.36, respectively). Interobserver agreement for Mb was almost perfect irrespective of prior experience (κ = 0.87/0.91/0.88, respectively). Observers with low experience, when compared with intermediate and high experience, demonstrated significantly lower median overall agreement (54% vs. 66% and 76%, P = 0.041) and specificity for T staging (73% vs. 88% and 93%, P = 0.032). Conclusion: The interpretation of ⁶⁸Ga-PSMA-11 PET/CT for prostate cancer staging is highly consistent among observers with high levels of experience, especially for nodal and bone assessments. Initial training on at least 30 patient cases is recommended to ensure acceptable performance.

前列腺癌患者中⁶⁸ Ga-PSMA-11 PET / CT研究解释的观察者间协议尚不清楚。方法： 对50例前列腺癌患者进行了⁶⁸ Ga-PSMA-11 PET / CT检查，检查结果包括生化复发（n = 25），初步诊断（n = 10），主要治疗后的生化持续（n = 5）或分期。已知转移性疾病（n = 10）。16位观察者对图像进行了审查，他们使用标准化的方法来解释局部（T），淋巴结（N），骨骼（Mb）或内脏（Mc）的受累情况。观察者被分类为低（<30之前的⁶⁸ Ga-PSMA-11 PET / CT研究; n= 5），中级（30-300个研究；n = 5）或高水平的经验（> 300个研究；n = 6）。组织病理学（n = 25，50 ％），束外放射治疗后前列腺特异性抗原反应（n = 15，30％）或随访PET / CT（n = 10，20％）为标准参考。观察者组通过总体一致性（符合参考标准的患者百分比）和Fleiss'κ进行比较，均值和相应的置信区间（CI）为95％。结果：对于T（κ= 0.62; 95％CI，0.59–0.64）和N（κ= 0.74; 95％CI，0.71-0.76）分期，所有观察者之间的共识是实质性的，对于Mb（κ= 0.88; 95％CI）几乎是完美的，0.86–0.91）分期。经验水平与T（分别为高/中/低经验的κ= 0.73 / 0.66 / 0.50），N（分别为κ= 0.80 / 0.76 / 0.64）和Mc分期的一致性一致（κ= 0.61 / 0.46） /0.36）。不论先前的经验如何，观察者之间对Mb的一致性几乎是完美的（分别为κ= 0.87 / 0.91 / 0.88）。与中级和高级经验相比，经验不足的观察者的总体中位协议满意度（54％对66％和76％，P = 0.041）显着降低，并且对T分期的特异性较低（73％对88％和93％，P = 0.032）。结论：⁶⁸ Ga-PSMA-11 PET / CT用于前列腺癌分期的解释在经验丰富的观察者中高度一致，尤其是在淋巴结和骨评估方面。建议至少对30例患者进行初步培训，以确保表现令人满意。