Rasmussen J H, Fischer B M, Aznar M C, Hansen A E, Vogelius I R, Löfgren J, Andersen F L, Loft A, Kjaer A, Højgaard L, Specht L
1 Department of Oncology, Section of Radiotherapy, Rigshospitalet, University of Copenhagen, Copenhagen, Denmark.
Br J Radiol. 2015 Apr;88(1048):20140655. doi: 10.1259/bjr.20140655. Epub 2015 Jan 30.
To investigate reproducibility of fluorine-18 fludeoxyglucose ((18)F-FDG) uptake on (18)F-FDG positron emission tomography (PET)/CT and (18)F-FDG PET/MR scans in patients with head and neck squamous cell carcinoma (HNSCC).
30 patients with HNSCC were included in this prospective study. The patients were scanned twice before radiotherapy treatment with both PET/CT and PET/MR. Patients were scanned on the same scanners, 3 days apart and according to the same protocol. Metabolic tumour activity was measured by the maximum and peak standardized uptake value (SUVmax and SUVpeak, respectively), and total lesion glycolysis from the metabolic tumour volume defined from ≥50% SUVmax. Bland-Altman analysis with limits of agreement, coefficient of variation (CV) from the two modalities were performed in order to test the reproducibility. Furthermore, CVs from SUVmax and SUVpeak were compared. The area under the curve from cumulative SUV-volume histograms were measured and tested for reproducibility of the distribution of (18)F-FDG uptake.
24 patients had two pre-treatment PET/CT scans and 21 patients had two pre-treatment PET/MR scans available for further analyses. Mean difference for SUVmax, peak and mean was approximately 4% for PET/CT and 3% for PET/MR, with 95% limits of agreement less than ±20%. CV was small (5-7%) for both modalities. There was no significant difference in CVs between PET/CT and PET/MR (p = 0.31). SUVmax was not more reproducible than SUVpeak (p = 0.09).
(18)F-FDG uptake in PET/CT and PET/MR is highly reproducible and we found no difference in reproducibility between PET/CT and PET/MR.
This is the first report to test reproducibility of PET/CT and PET/MR.
探讨头颈部鳞状细胞癌（HNSCC）患者在18F-氟脱氧葡萄糖（18F-FDG）正电子发射断层扫描（PET）/CT及18F-FDG PET/MR扫描中18F-FDG摄取的可重复性。
30例HNSCC患者纳入本前瞻性研究。患者在放疗前分别接受PET/CT和PET/MR扫描各两次。患者在同一台扫描仪上扫描，间隔3天，且扫描方案相同。通过最大标准化摄取值和峰值标准化摄取值（分别为SUVmax和SUVpeak）以及根据≥50% SUVmax定义的代谢肿瘤体积计算的总病变糖酵解来测量代谢肿瘤活性。采用一致性界限的Bland-Altman分析以及两种检查方式的变异系数（CV）来检验可重复性。此外，比较SUVmax和SUVpeak的CV。测量累积SUV-体积直方图的曲线下面积，并检验18F-FDG摄取分布的可重复性。
24例患者有两次治疗前PET/CT扫描结果，21例患者有两次治疗前PET/MR扫描结果可供进一步分析。PET/CT的SUVmax、峰值和均值的平均差异约为4%，PET/MR约为3%，95%一致性界限小于±20%。两种检查方式的CV均较小（5 - 7%）。PET/CT和PET/MR的CV之间无显著差异（p = 0.31）。SUVmax的可重复性并不优于SUVpeak（p = 0.09）。
PET/CT和PET/MR中18F-FDG摄取具有高度可重复性，且我们发现PET/CT和PET/MR在可重复性方面无差异。
这是首篇检验PET/CT和PET/MR可重复性的报告。
