Department of Neuroradiology, Sorbonne Université, Assistance Publique-Hôpitaux de Paris, Groupe Hospitalier Pitié-Salpêtrière-Charles Foix.
Sorbonne Université, INSERM, CNRS, Assistance Publique-Hôpitaux de Paris, Institut du Cerveau et de la Moelle épinière, boulevard de l'Hôpital, Paris.
Curr Opin Oncol. 2021 Nov 1;33(6):597-607. doi: 10.1097/CCO.0000000000000793.
This review aims to cover current MRI techniques for assessing treatment response in brain tumors, with a focus on radio-induced lesions.
Pseudoprogression and radionecrosis are common radiological entities after brain tumor irradiation and are difficult to distinguish from real progression, with major consequences on daily patient care. To date, shortcomings of conventional MRI have been largely recognized but morphological sequences are still used in official response assessment criteria. Several complementary advanced techniques have been proposed but none of them have been validated, hampering their clinical use. Among advanced MRI, brain perfusion measures increase diagnostic accuracy, especially when added with spectroscopy and susceptibility-weighted imaging. However, lack of reproducibility, because of several hard-to-control variables, is still a major limitation for their standardization in routine protocols. Amide Proton Transfer is an emerging molecular imaging technique that promises to offer new metrics by indirectly quantifying intracellular mobile proteins and peptide concentration. Preliminary studies suggest that this noncontrast sequence may add key biomarkers in tumor evaluation, especially in posttherapeutic settings.
Benefits and pitfalls of conventional and advanced imaging on posttreatment assessment are discussed and the potential added value of APT in this clinicoradiological evolving scenario is introduced.
本综述旨在介绍目前用于评估脑肿瘤治疗反应的 MRI 技术，重点是放射性损伤。
脑肿瘤放疗后常见的放射性病变包括假性进展和放射性坏死，难以与真正的进展相区分，这对患者的日常治疗有重大影响。迄今为止，常规 MRI 的局限性已得到广泛认可，但形态学序列仍用于官方的反应评估标准。已经提出了几种补充的高级技术，但都没有得到验证，这阻碍了它们的临床应用。在高级 MRI 中，脑灌注测量可提高诊断准确性，尤其是与波谱和磁敏感加权成像相结合时。然而，由于难以控制的多种变量，缺乏可重复性仍然是将其标准化纳入常规方案的主要限制。酰胺质子转移是一种新兴的分子成像技术，有望通过间接定量细胞内可移动蛋白和肽浓度提供新的指标。初步研究表明，这种无对比序列可能在肿瘤评估中增加关键的生物标志物，特别是在治疗后。
讨论了常规和高级影像学在治疗后评估中的优缺点，并介绍了 APT 在这种临床影像学不断发展的情况下的潜在附加价值。
