Department of Radiation Oncology and Image-applied Therapy, Graduate School of Medicine, Kyoto University, 54 Kawahara-cho, Shogoin, Sakyo-ku, Kyoto, 606-8507, Japan.
Division of Clinical Radiology Service, Kyoto University Hospital, Kyoto, Japan.
Mol Imaging Biol. 2021 Aug;23(4):597-603. doi: 10.1007/s11307-021-01580-6. Epub 2021 Jan 21.
Positron emission tomography (PET)/computed tomography (CT) using F-fluoromisonidazole (FMISO) has been used as an imaging tool for tumour hypoxia. However, it remains unclear whether they are useful when scanning is performed earlier, e.g. at 2-h post-injection with a high sensitivity PET scanner. This study aimed to investigate the relationship between quantitative values in F-fluoromisonidazole (F-FMISO)-PET obtained at 2- and 4-h post-injection in patients with head and neck cancer.
We enrolled 20 patients with untreated locally advanced head and neck cancer who underwent F-FMISO-PET/CT scan between August 2015 and March 2018 at our institute. Image acquisition was performed 2 h and 4 h after F-FMISO administration using a combined PET/CT scanner. The SUVmax, SUVmean, SUVpeak, tumour-to-blood ratio (TBR), tumour-to-muscle ratio (TMR), metabolic tumour volume (MTV), and total lesion hypoxia (TLH) were measured in the region of interest of the primary tumour. We evaluated the between-image Spearman's rank correlation coefficients and percentage differences in the quantitative values. The locations of the maximum uptake pixel were identified in both scans, and the distance between them was measured.
The mean (SD) SUVmax at 2 h and 4 h was 2.2(0.7) and 2.4(0.8), respectively. The Spearman's rank correlation coefficients (ρ) and mean (SD) of the percentage differences of the measures were as follows: SUVmax (0.97; 7.0 [5.1]%), SUVmean (0.97; 5.2 [5.8]%), SUVpeak (0.94; 5.3 [4.7]%), TBR (0.96; 14.2 [9.8]%), TMR (0.96; 14.7 [8.4]%), MTV (0.98; 39.9 [41.3]%), and TLH (0.98; 40.1 [43.4]%). There were significant between-scan correlations in all quantitative values. The mean (SD) distance between the two maximum uptake pixels was 7.3 (5.3) mm.
We observed a high correlation between the quantitative values at 2 h and 4 h. When using a combined high-quality PET/CT, the total examination time for FMISO-PET can be shortened by skipping the 4-h scan.
正电子发射断层扫描（PET）/计算机断层扫描（CT）联合 F-氟代硝基咪唑（FMISO）已被用作肿瘤缺氧的成像工具。然而，在使用高灵敏度 PET 扫描仪进行更早的扫描（例如注射后 2 小时）时，它们是否有用仍不清楚。本研究旨在探讨 2 小时和 4 小时注射后头颈癌患者 F-FMISO-PET 中定量值之间的关系。
我们招募了 20 名未接受治疗的局部晚期头颈癌患者，他们于 2015 年 8 月至 2018 年 3 月在我们的研究所接受了 F-FMISO-PET/CT 扫描。使用组合的 PET/CT 扫描仪在 FMISO 给药后 2 小时和 4 小时进行图像采集。在原发性肿瘤的感兴趣区域测量 SUVmax、SUVmean、SUVpeak、肿瘤与血液比（TBR）、肿瘤与肌肉比（TMR）、代谢肿瘤体积（MTV）和总肿瘤缺氧（TLH）。我们评估了定量值之间图像 Spearman 秩相关系数和百分比差异。在两次扫描中均确定了最大摄取像素的位置，并测量了它们之间的距离。
2 小时和 4 小时 SUVmax 的平均值（标准差）分别为 2.2（0.7）和 2.4（0.8）。测量的 Spearman 秩相关系数（ρ）和百分比差异的平均值（标准差）如下：SUVmax（0.97；7.0[5.1]%）、SUVmean（0.97；5.2[5.8]%）、SUVpeak（0.94；5.3[4.7]%）、TBR（0.96；14.2[9.8]%）、TMR（0.96；14.7[8.4]%）、MTV（0.98；39.9[41.3]%）和 TLH（0.98；40.1[43.4]%）。所有定量值均具有显著的扫描间相关性。两个最大摄取像素之间的平均（标准差）距离为 7.3（5.3）mm。
我们观察到 2 小时和 4 小时定量值之间存在高度相关性。当使用高质量的 PET/CT 组合时，可以通过跳过 4 小时扫描来缩短 FMISO-PET 的总检查时间。
