Rogasch Julian M M, Apostolova Ivayla, Steffen Ingo G, Steinkrüger Ferdinand L G A, Genseke Philipp, Riedel Sandra, Wertzel Heinz, Achenbach H Jost, Kalinski Thomas, Schultz Meinald, Schreiber Jens, Amthauer Holger, Furth Christian
Department of Radiology and Nuclear Medicine, University Hospital Magdeburg, Otto-von-Guericke University Magdeburg, Leipziger Strasse 44, 39120 Magdeburg, Germany.
Department of Radiology and Nuclear Medicine, University Hospital Magdeburg, Otto-von-Guericke University Magdeburg, Leipziger Strasse 44, 39120 Magdeburg, Germany.
Eur J Radiol. 2016 Aug;85(8):1345-50. doi: 10.1016/j.ejrad.2016.05.004. Epub 2016 May 11.
Routine visual assessment of positron emission tomography (PET) for thoracic lymph node (LN) staging in patients with non-small cell lung cancer (NSCLC) is limited by a lack of reliable assessment criteria. This study evaluates the accuracy and inter-rater agreement of a standardized approach with unified windowing and a PET-based visual score.
This retrospective analysis included pretherapeutic FDG-PET data of 86 patients with NSCLC. After standardized windowing (threshold: 2×liver SUVmean) the LN uptake was assessed visually by three independent readers with varying levels of experience using a 4-step score (1, LN uptake≤mediastinal blood pool structures (MBPS); 2, MBPS<LN<liver; 3, liver≤LN<'black'; 4, LN appears 'black'). ROC analyses and respective areas under the curve (AUC) based on histology/cytology as standard of reference. Agreement was analyzed with Cohen's kappa (κ, pairwise) and Fleiss' κ (overall). Subgroup analyses separated between hilar vs. mediastinal LNs, adenocarcinoma vs. squamous cell carcinoma and grading G1/2 vs. G3/4.
Fifty-four of the 278LNs (19.4%) were malignant (optimal cut-off to differentiate benign vs. malignant, score >3). The inexperienced (n=1), advanced (n=1), and expert readers (n=1) achieved similar accuracies of 93.5%, 91.4% and 92.1%, respectively (P>0.05 each). Cohen's κ ranged from 0.92 to 0.96 and Fleiss' κ was 0.93. ROC-analyses showed no significant differences between attendant readers within any subgroup (AUC, 0.92-0.96).
Applying unified windowing, the introduced PET-score achieved highly accurate and robust LN assessment. This approach may shorten learning curves of inexperienced readers, facilitate multicenter trials, and improve comparability of future studies.
非小细胞肺癌（NSCLC）患者胸部淋巴结（LN）分期的正电子发射断层扫描（PET）常规视觉评估因缺乏可靠的评估标准而受到限制。本研究评估了采用统一窗宽和基于PET的视觉评分的标准化方法的准确性和阅片者间一致性。
这项回顾性分析纳入了86例NSCLC患者的治疗前FDG-PET数据。在进行标准化窗宽设置（阈值：2×肝脏SUVmean）后，由三名经验水平不同的独立阅片者使用4级评分（1，LN摄取≤纵隔血池结构（MBPS）；2，MBPS＜LN＜肝脏；3，肝脏≤LN＜“黑色”；4，LN呈“黑色”）对LN摄取情况进行视觉评估。基于组织学/细胞学作为参考标准进行ROC分析及相应的曲线下面积（AUC）计算。采用Cohen's kappa（κ，两两比较）和Fleiss' κ（总体）分析一致性。亚组分析按肺门LN与纵隔LN、腺癌与鳞状细胞癌以及G1/2级与G3/4级进行划分。
278个LN中有54个（19.4%）为恶性（区分良性与恶性的最佳截断值为评分＞3）。经验不足的阅片者（n = 1）、经验丰富的阅片者（n = 1）和专家阅片者（n = 1）分别获得了相似的准确率，分别为93.5%、91.4%和92.1%（两两比较P＞0.05）。Cohen's κ范围为0.92至0.96，Fleiss' κ为0.93。ROC分析显示，任何亚组内的阅片者之间均无显著差异（AUC，0.92 - 0.96）。
应用统一窗宽，引入的PET评分实现了高度准确且可靠的LN评估。这种方法可能会缩短经验不足的阅片者的学习曲线，便于多中心试验，并提高未来研究的可比性。
