头颈鳞状细胞癌（HNSCC）仍然是一种局部复发率高且复发病例预后不良的恶性肿瘤。亚临床病变的早期发现具有挑战性，但对于有效的患者管理至关重要。治疗后的影像学监测，特别是 18F-FDG PET/CT，在诊断 HNSCC 复发方面显示出了希望。目的是根据治疗后延迟评估 18F-FDG PET/CT 在检测 HNSCC 患者亚临床复发 (SCR) 方面的诊断性能。方法：在这项回顾性研究中，所有 18F-FDG PET/CT 扫描均在单个中心进行。所有经组织学证实患有 HNSCC 且在 2006 年 1 月 1 日至 2021 年 12 月 31 日期间接受治疗的成人均被纳入。每次扫描前他们都会进行正常的临床检查。治疗后接受强化随访策略的患者在 3-6 个月内进行 18F-FDG PET/CT 静脉注射造影剂，此后每年进行一次，持续 5 年。主要终点是诊断表现（阳性和阴性预测值、敏感性、特异性和准确性）。结果：总共对 852 名患者进行了 2,566 次 18F-FDG PET/CT 扫描，平均每名患者进行 3 次扫描。总体诊断性能指标如下：阳性预测值（88%）、阴性预测值（98%）、敏感性（98%）、特异性（89%）和准确性（93%）。随着时间的推移，诊断性能没有显着差异。扫描检测出 126 例 SCR (14.8%) 和 118 例异时性癌症 (13.8%)。 SCR 的发生率随着时间的推移而下降，治疗后的前 2 年检出率最高。随着时间的推移，阳性预测值不断提高，数字 Vision 600 系统（第三期）的阳性预测值达到 90%，而模拟 Gemini GXLi 系统的阳性预测值为 76%（第一期，P < 0.001）。多变量分析确定晚期、高体重指数和初始 PET/CT 分期为 SCR 检测的预测因素。结论：我们的研究表明，18F-FDG PET/CT 在 HNSCC 治疗后随访期间（尤其是前 2 年）检测 SCR 方面具有较高的诊断性能。晚期肿瘤分期、初始 PET/CT 分期和高体重指数与 SCR 检测的较高可能性相关。对于 HNSCC 患者，在随访期间常规使用 18F-FDG PET/CT 似乎是合理的。© 2024，核医学和分子影像学会。

Head and neck squamous cell carcinoma (HNSCC) remains a malignancy with high rates of locoregional recurrence and poor prognosis for recurrent cases. Early detection of subclinical lesions is challenging but critical for effective patient management. Imaging surveillance after treatment, particularly 18F-FDG PET/CT, has shown promise in the diagnosis of HNSCC recurrence. The aim was to evaluate the diagnostic performance of 18F-FDG PET/CT according to delay after treatment in detecting subclinical recurrence (SCR) in HNSCC patients. Methods: In this retrospective study, all 18F-FDG PET/CT scans were performed at a single center. All adults with histologically proven HNSCC who were treated with curative intent between January 1, 2006, and December 31, 2021, were included. They had a normal clinical examination before each scan. Patients who underwent an intensive follow-up strategy after treatment had 18F-FDG PET/CT with an intravenous contrast agent at 3-6 mo and annually thereafter for 5 y. The primary endpoint was diagnostic performance (positive and negative predictive values, sensitivity, specificity, and accuracy). Results: In total, 2,566 18F-FDG PET/CT scans were performed among 852 patients, with an average of 3 scans per patient. The overall diagnostic performance measures were as follows: positive predictive value (88%), negative predictive value (98%), sensitivity (98%), specificity (89%), and accuracy (93%). There were no significant differences in diagnostic performance over time. The scans detected 126 cases of SCR (14.8%) and 118 cases of metachronous cancer (13.8%). The incidence of SCR decreased over time, with the highest detection rate in the first 2 y after treatment. Positive predictive value improved over time, reaching 90% for the digital Vision 600 system (third period) compared with 76% for the analog Gemini GXLi system (first period, P < 0.001). Multivariate analysis identified advanced stage, high body mass index, and initial PET/CT upstaging as predictive factors for detection of SCR. Conclusion: Our study demonstrates that 18F-FDG PET/CT has high diagnostic performance in detecting SCR during follow-up after treatment of HNSCC, especially in the first 2 y. Advanced tumor stage, initial PET/CT upstaging, and high body mass index were associated with a higher likelihood of SCR detection. The routine use of 18F-FDG PET/CT during follow-up seems justified for patients with HNSCC.© 2024 by the Society of Nuclear Medicine and Molecular Imaging.