Kerkhof M, Hagenbeek R E, van der Kallen B F W, Lycklama À Nijeholt G J, Dirven L, Taphoorn M J B, Vos M J
Department of Neurology, Medical Center Haaglanden, The Hague, The Netherlands.
Department of Radiology, Medical Center Haaglanden, The Hague, The Netherlands.
Eur J Neurol. 2016 Oct;23(10):1528-33. doi: 10.1111/ene.13070. Epub 2016 Jul 18.
Conventional magnetic resonance imaging (MRI) has limited value for differentiation of true tumor progression and pseudoprogression in treated glioblastoma multiforme (GBM). Perfusion weighted imaging (PWI) may be helpful in the differentiation of these two phenomena. Here interobserver variability in routine radiological evaluation of GBM patients is assessed using MRI, including PWI.
Three experienced neuroradiologists evaluated MR scans of 28 GBM patients during temozolomide chemoradiotherapy at three time points: preoperative (MR1) and postoperative (MR2) MR scan and the follow-up MR scan after three cycles of adjuvant temozolomide (MR3). Tumor size was measured both on T1 post-contrast and T2 weighted images according to the Response Assessment in Neuro-Oncology criteria. PW images of MR3 were evaluated by visual inspection of relative cerebral blood volume (rCBV) color maps and by quantitative rCBV measurements of enhancing areas with highest rCBV. Image interpretability of PW images was also scored. Finally, the neuroradiologists gave a conclusion on tumor status, based on the interpretation of both T1 and T2 weighted images (MR1, MR2 and MR3) in combination with PWI (MR3).
Interobserver agreement on visual interpretation of rCBV maps was good (κ = 0.63) but poor on quantitative rCBV measurements and on interpretability of perfusion images (intraclass correlation coefficient 0.37 and κ = 0.23, respectively). Interobserver agreement on the overall conclusion of tumor status was moderate (κ = 0.48).
Interobserver agreement on the visual interpretation of PWI color maps was good. However, overall interpretation of MR scans (using both conventional and PW images) showed considerable interobserver variability. Therefore, caution should be applied when interpreting MRI results during chemoradiation therapy.
传统磁共振成像（MRI）在鉴别多形性胶质母细胞瘤（GBM）治疗后的真正肿瘤进展与假性进展方面价值有限。灌注加权成像（PWI）可能有助于区分这两种现象。本文使用包括PWI在内的MRI评估GBM患者常规放射学评估中的观察者间变异性。
三位经验丰富的神经放射科医生在替莫唑胺同步放化疗期间的三个时间点评估了28例GBM患者的磁共振扫描：术前（MR1）、术后（MR2）磁共振扫描以及辅助替莫唑胺三个周期后的随访磁共振扫描（MR3）。根据神经肿瘤学疗效评估标准，在T1增强和T2加权图像上测量肿瘤大小。通过目视检查相对脑血容量（rCBV）彩色图以及对rCBV最高的强化区域进行定量rCBV测量来评估MR3的PW图像。还对PW图像的图像可解释性进行评分。最后，神经放射科医生根据T1和T2加权图像（MR1、MR2和MR3）以及PWI（MR3）的解释对肿瘤状态得出结论。
观察者间对rCBV图的视觉解释一致性良好（κ = 0.63），但在定量rCBV测量和灌注图像的可解释性方面较差（组内相关系数分别为0.37和κ = 0.23）。观察者间对肿瘤状态总体结论的一致性为中等（κ = 0.48）。
观察者间对PWI彩色图的视觉解释一致性良好。然而，磁共振扫描的总体解释（使用传统图像和PW图像）显示出相当大的观察者间变异性。因此，在放化疗期间解释MRI结果时应谨慎。
