Division of Nuclear Medicine, Department Medical Radiology, University Hospital of Zurich, Zurich, Switzerland.
Clin Nucl Med. 2011 Oct;36(10):848-53. doi: 10.1097/RLU.0b013e3182177322.
To analyze the effect of H1N1 influenza A virus vaccination in patients referred for staging or follow-up F-18 fluorodeoxyglucose (FDG) positron emission tomography/computed tomography (PET/CT) for different malignant tumors.
Medical history of all patients scheduled for FDG PET/CT during the national vaccination campaign against H1N1 was evaluated for recent vaccination. Site of injection and time between PET/CT and the date of vaccination (dTime) was determined. A difference in the maximum SUV between ipsi- and contralateral deltoid muscle or axillary lymph node of more than 0.5 was determined as positive reaction. The best cut-off dTime for still visible reaction was calculated. All patients with positive ipsilateral lymph node were clinically followed. Institutional Review Board approval was waived.
Of 269 patients, 58 (21.5%) were vaccinated for the H1N1 within 4 weeks prior to PET/CT (mean, 14.5 ± 8.7 days). Of them, 17 (29.3%) patients had FDG-positive lymph nodes (mean SUV, 1.43 ± 1.06), with a dTime range from 1 to 14 days. Only 2 of them had no increased FDG uptake in the ipsilateral deltoid muscle. The area under the receiver operator characteristic curve revealed a strong relation between time delay (dTime) and axillary activity (AUC, 0.9; 95% confidence interval, 0.816-0.983) with a cutoff at 8 days (Youden Index). At follow-up (mean, 183 days; range, 173-196 days), no patient was found to have required treatment or signs of axillary lymphadenopathy.
H1N1 vaccination can cause false-positive FDG PET/CT findings, when administered less than 14 days before the test, with the highest probability if the vaccination was administered less than 8 days ago. Increased FDG activity in the ipsilateral deltoid muscle is a key finding for accurate interpretation of increased FDG activity in axillary lymph nodes.
分析甲型 H1N1 流感病毒疫苗接种对不同恶性肿瘤进行分期或随访 F-18 氟脱氧葡萄糖（FDG）正电子发射断层扫描/计算机断层扫描（PET/CT）的患者的影响。
评估了所有在全国甲型 H1N1 流感疫苗接种期间接受 FDG PET/CT 检查的患者的病史，以了解近期的疫苗接种情况。确定注射部位和 PET/CT 与疫苗接种日期之间的时间（dTime）。如果同侧三角肌或腋窝淋巴结的最大 SUV 差值大于 0.5，则确定为阳性反应。计算仍可见反应的最佳 dTime 截止值。所有同侧淋巴结阳性的患者均进行临床随访。豁免机构审查委员会的批准。
在 269 名患者中，有 58 名（21.5%）在 PET/CT 前 4 周内（平均 14.5±8.7 天）接种了 H1N1 疫苗。其中，17 名（29.3%）患者的 FDG 阳性淋巴结（平均 SUV，1.43±1.06），dTime 范围为 1-14 天。只有 2 名患者同侧三角肌无 FDG 摄取增加。受试者工作特征曲线下面积显示，时间延迟（dTime）与腋窝活性（AUC，0.9；95%置信区间，0.816-0.983）之间存在很强的关系，截断值为 8 天（约登指数）。在随访期间（平均 183 天；范围 173-196 天），未发现患者需要治疗或出现腋窝淋巴结病迹象。
如果在检查前 14 天内接种疫苗，尤其是在接种疫苗后 8 天内接种疫苗，H1N1 疫苗接种可能会导致 FDG PET/CT 出现假阳性结果。同侧三角肌中 FDG 活性增加是准确解释腋窝淋巴结中 FDG 活性增加的关键发现。
