De Lucia Federico, Lefebvre Yolene, Lemort Marc P
Department of Radiology, Jules Bordet Institute, Université Libre de Bruxelles, Brussels, Belgium.
Eur J Radiol Open. 2022 Nov 11;9:100449. doi: 10.1016/j.ejro.2022.100449. eCollection 2022.
The main objective of the study is to assess the feasibility and reproducibility of routine MRS to assist in the differential diagnosis between post-radiation necrosis and tumor progression. The secondary objective is to evaluate the accuracy of the method.
An additional sequence of MRS was added to the standard protocol routinely used for patient follow-up. To assess discomfort a control group was formed. The time required to perform MRS and analysis of results, and data about artefacts and technical limitations were collected. MRS results analyzed independently by two neuroradiologists were compared. The diagnostic accuracy of MRS was calculated using a composite reference standard.
The experimental group included 38 patients, the control group 41. The discomfort felt during the examination, is not significantly different between the groups. The average quality of SRM is rated as low. The frequency of cerebral radionecrosis is 13 % based on the reference standard used, 54 % and 46 % based on MRS results for the two observers. The additional time is 19,5 min. There is strong inter-observer agreement. The sensitivity and specificity of MRS are respectively for the diagnosis of radionecrosis of 60 % and 45 % (PPV = 16 %NPV = 87 %), for the diagnosis of tumor tissue of 25 % and 94 % (PPV = 80 %NPV = 57%).
MRS is probably not applicable in routine clinical practice; however, in view of our results and the literature, in selected cases, it could be a support in the diagnosis of radionecrosis or brain tumor progression. Radionecrosis is probably underestimated.
本研究的主要目的是评估常规磁共振波谱（MRS）在辅助鉴别放射性坏死和肿瘤进展方面的可行性和可重复性。次要目的是评估该方法的准确性。
在患者常规随访使用的标准方案中增加了一组额外的MRS序列。为评估不适感，设立了一个对照组。收集了进行MRS及分析结果所需的时间，以及关于伪影和技术限制的数据。比较了由两名神经放射科医生独立分析的MRS结果。使用综合参考标准计算MRS的诊断准确性。
实验组包括38例患者，对照组包括41例患者。两组在检查过程中感受到的不适感无显著差异。单体素磁共振波谱（SRM）的平均质量被评为较低。根据所使用的参考标准，脑放射性坏死的发生率为13%，基于两名观察者的MRS结果分别为54%和46%。额外时间为19.5分钟。观察者间存在很强的一致性。MRS诊断放射性坏死的敏感性和特异性分别为60%和45%（阳性预测值=16%，阴性预测值=87%），诊断肿瘤组织的敏感性和特异性分别为25%和94%（阳性预测值=80%，阴性预测值=57%）。
MRS可能不适用于常规临床实践；然而，鉴于我们的研究结果和文献，在某些特定病例中，它可能有助于放射性坏死或脑肿瘤进展的诊断。放射性坏死可能被低估了。
