Bosch Paul, Glaudemans Andor W J M, de Vries Jean-Paul P M, van Snick Johannes H, Lemans Justin V C, van den Kieboom Janna, Hobbelink Monique G G, Govaert Geertje A M, IJpma Frank F A
Department of Surgery, University Medical Center Groningen, University of Groningen, 9712 CP Groningen, The Netherlands.
Department of Nuclear Medicine and Molecular Imaging, University Medical Center Groningen, University of Groningen, 9712 CP Groningen, The Netherlands.
Diagnostics (Basel). 2025 Mar 4;15(5):616. doi: 10.3390/diagnostics15050616.
Diagnosing fracture-related infection (FRI) without clinical confirmatory signs is challenging. [18F]FDG-PET/CT has been shown to have good diagnostic accuracy. However, direct interpretation criteria are lacking. The aim of this study was to assess the diagnostic value of increased FDG-uptake in locoregional lymph nodes on [18F]FDG-PET/CT in patients with suspected upper and lower extremity FRI. : This was a retrospective cohort study of patients who underwent [18F]FDG-PET/CT for suspected extremity FRI in two tertiary referral centers between January 2011 and December 2023. The sensitivity, specificity and diagnostic value of the presence, number and intensity of [18F]FDG uptake in locoregional lymph nodes was assessed. Uptake intensity was measured by calculating the maximum standard uptake value (SUVmax) of the 'hottest' lymph node. All scans were acquired according to the European Association of Nuclear Medicine (EANM) standards, and quantification was performed based on standardized EARL reconstructed images. FRI was diagnosed based on positive intra-operative microbiology results or development of clinical confirmatory signs within six months of follow-up. : One-hundred-and-twenty-four patients were included in the analysis, with 71 cases of confirmed FRI. The presence of locoregional lymph nodes alone showed poor diagnostic accuracy (sensitivity 55%, specificity 68%, diagnostic accuracy 62%). The number of active lymph nodes showed poor discriminative performance between FRI and non-infectious cases (AUC 0.63). Utilizing the SUVmax of the 'hottest' lymph nodes showed a moderate discriminative performance with an AUC of 0.71. The optimal cutoff point (SUVmax 3.48) resulted in a sensitivity of 72%, a specificity of 78% and a diagnostic accuracy of 75%. A logistic regression model was fitted to calculate the added value of lymph node assessment to the regular [18F]FDG-PET/CT assessment. This resulted in a sensitivity of 71%, a specificity of 82% and a diagnostic accuracy of 76%. : Presence and number of locoregional lymph nodes with increased [18F]FDG-uptake alone has poor diagnostic accuracy for FRI. The SUVmax of the 'hottest' lymph node showed moderate diagnostic performance. Lymph node assessment slightly increased the diagnostic value of regular [18F]FDG-PET/CT assessment. Based on these results, increased [18F]FDG-uptake in locoregional lymph nodes should only be considered as a suggestive sign for a positive scan result in suspected FRI.
在没有临床确诊体征的情况下诊断骨折相关感染（FRI）具有挑战性。[18F]氟代脱氧葡萄糖正电子发射断层扫描/计算机断层扫描（[18F]FDG-PET/CT）已被证明具有良好的诊断准确性。然而，缺乏直接的解读标准。本研究的目的是评估[18F]FDG-PET/CT上局部区域淋巴结中FDG摄取增加对疑似上下肢FRI患者的诊断价值。：这是一项回顾性队列研究，研究对象为2011年1月至2023年12月期间在两个三级转诊中心因疑似肢体FRI接受[18F]FDG-PET/CT检查的患者。评估了局部区域淋巴结中[18F]FDG摄取的存在、数量和强度的敏感性、特异性和诊断价值。摄取强度通过计算“最热点”淋巴结的最大标准摄取值（SUVmax）来测量。所有扫描均按照欧洲核医学协会（EANM）标准进行采集，并基于标准化的EARL重建图像进行定量分析。FRI根据术中微生物学阳性结果或随访6个月内出现的临床确诊体征进行诊断。：124例患者纳入分析，其中71例确诊为FRI。仅局部区域淋巴结的存在显示出较差的诊断准确性（敏感性55%，特异性68%，诊断准确性62%）。活跃淋巴结的数量在FRI和非感染性病例之间的鉴别性能较差（曲线下面积[AUC]为0.63）。利用“最热点”淋巴结的SUVmax显示出中等的鉴别性能，AUC为0.71。最佳截断点（SUVmax为3.48）导致敏感性为72%，特异性为78%，诊断准确性为75%。拟合逻辑回归模型以计算淋巴结评估相对于常规[18F]FDG-PET/CT评估的附加值。这导致敏感性为71%，特异性为82%，诊断准确性为76%。：仅[18F]FDG摄取增加的局部区域淋巴结的存在和数量对FRI的诊断准确性较差。“最热点”淋巴结的SUVmax显示出中等的诊断性能。淋巴结评估略微增加了常规[18F]FDG-PET/CT评估的诊断价值。基于这些结果，局部区域淋巴结中[18F]FDG摄取增加仅应被视为疑似FRI扫描结果阳性的提示性征象。
