Pediatric Oncology Branch, Center for Cancer Research, National Cancer Institute, National Institutes of Health, 9000 Rockville Pike, Bethesda, MD 20892, USA.
J Neurooncol. 2012 Sep;109(3):521-7. doi: 10.1007/s11060-012-0918-0. Epub 2012 Jul 4.
Magnetic resonance spectroscopic imaging (MRSI) and (18)F-fluorodeoxyglucose positron emission tomography (FDG-PET) are non-invasive imaging techniques routinely used to evaluate tumor malignancy in adults with brain tumors. We compared the metabolic activity of pediatric brain tumors using FDG-PET and MRSI. Children (n = 37) diagnosed with a primary brain tumor underwent FDG-PET and MRSI within two weeks of each other. Tumor metabolism was classified as inactive, active or highly active using the maximum choline:N-acetyl-asparate (Cho:NAA) on MRSI and the highest tumor uptake on FDG-PET. A voxel-wise comparison was used to evaluate the area with the greatest abnormal metabolism. Agreement between methods was assessed using the percent agreement and the kappa statistic (κ). Pediatric brain tumors were metabolically heterogeneous on FDG-PET and MRSI studies. Active tumor metabolism was observed more frequently using MRSI compared to FDG-PET, and agreement in tumor classification was weak (κ = 0.16, p = 0.12), with 42 % agreement (95 % CI = 25-61 %). Voxel-wise comparison for identifying the area of greatest metabolic activity showed overlap in the majority (62 %) of studies, though exact agreement between techniques was low (29.4 %, 95 % CI = 15.1-47.5 %). These results indicate that FDG-PET and MRSI detect similar but not always identical regions of tumor activity, and there is little agreement in the degree of tumor metabolic activity between the two techniques.
磁共振波谱成像（MRSI）和（18）F-氟代脱氧葡萄糖正电子发射断层扫描（FDG-PET）是常规用于评估成人脑肿瘤恶性程度的非侵入性成像技术。我们比较了使用 FDG-PET 和 MRSI 对小儿脑肿瘤的代谢活性。在两周内，患有原发性脑肿瘤的儿童接受了 FDG-PET 和 MRSI。使用 MRSI 上最大的胆碱：N-乙酰天冬氨酸（Cho：NAA）和 FDG-PET 上最高的肿瘤摄取率，将肿瘤代谢分为不活跃、活跃或高度活跃。使用体素比较来评估代谢异常最严重的区域。使用百分比一致性和 Kappa 统计量（κ）评估方法之间的一致性。在 FDG-PET 和 MRSI 研究中，小儿脑肿瘤的代谢是异质的。与 FDG-PET 相比，MRSI 观察到更多的活跃肿瘤代谢，肿瘤分类的一致性较弱（κ=0.16，p=0.12），有 42%的一致性（95%CI=25-61%）。用于识别代谢活性最大区域的体素比较显示，在大多数（62%）研究中存在重叠，但两种技术之间的精确一致性较低（29.4%，95%CI=15.1-47.5%）。这些结果表明，FDG-PET 和 MRSI 检测到相似但并非总是相同的肿瘤活性区域，两种技术之间的肿瘤代谢活性程度一致性较小。
