Department of Radiology, Adnan Menderes University, School of Medicine, Hastane Caddesi, Aydin, Turkey.
Acad Radiol. 2010 Mar;17(3):282-90. doi: 10.1016/j.acra.2009.10.024. Epub 2010 Jan 12.
Distinguishing recurrent glial tumor from radiation necrosis can be challenging. The purpose of this pilot study was to preliminarily compare unenhanced arterial spin-labeled (ASL) imaging, dynamic susceptibility contrast-enhanced cerebral blood volume (DSCE-CBV) magnetic resonance imaging, and positron emission tomographic (PET) imaging in distinguishing predominant glioma recurrence or progression from predominant radiation necrosis in postoperative patients treated with proton-beam therapy.
Patients with grade II to IV glioma previously treated with surgery and proton-beam therapy were enrolled on the basis of new enhancing nodules or masses with primary differential diagnoses of predominant tumor recurrence or progression versus radiation necrosis. ASL, DSCE-CBV, and PET examinations were assessed by visual qualitative and quantitative analysis for the detection of predominant tumor recurrence. Imaging results were correlated with a clinical-pathologic reference standard.
Thirty patients were studied, resulting in 33 ASL, 32 DSCE-CBV, and 26 PET examinations. On the basis of visual inspection, the sensitivities of PET, ASL, and DSCE-CBV examinations for detecting high-grade tumor foci were 81%, 88%, and 86%, respectively. The highest sensitivity values for quantitative ASL imaging were obtained using a normalized cutoff ratio of 1.3, resulting in sensitivity of 94% for ASL imaging and 71% for DSCE-CBV imaging. When predominant high-grade tumors with superimposed regions of predominant mixed radiation necrosis were excluded, DSCE-CBV sensitivity improved to 90%, but ASL sensitivity remained unchanged.
Compared with DSCE-CBV imaging, ASL imaging may more accurately distinguish predominant recurrent high-grade glioma from radiation necrosis, especially in regions with mixed radiation necrosis, for which DSCE-CBV imaging may underestimate true blood volume because of leakage artifacts.
鉴别复发性神经胶质瘤与放射性坏死具有一定挑战性。本研究旨在初步比较未增强动脉自旋标记（ASL）成像、动态磁敏感对比增强脑血容量（DSCE-CBV）磁共振成像和正电子发射断层扫描（PET）成像在质子放疗术后患者中鉴别以肿瘤复发性为主与以放射性坏死为主的新增强病灶或肿块的作用。
基于新出现的增强结节或肿块的主要鉴别诊断为以肿瘤复发性为主还是以放射性坏死为主，我们对先前接受手术和质子放疗治疗的 II 级至 IV 级神经胶质瘤患者进行了招募。通过视觉定性和定量分析评估 ASL、DSCE-CBV 和 PET 检查以检测主要肿瘤复发性。将影像学结果与临床病理参考标准相关联。
共 30 例患者入组，共进行了 33 次 ASL、32 次 DSCE-CBV 和 26 次 PET 检查。基于视觉检查，PET、ASL 和 DSCE-CBV 检查检测高级别肿瘤灶的敏感度分别为 81%、88%和 86%。定量 ASL 成像的最高敏感度值采用归一化截断比 1.3 获得，ASL 成像的敏感度为 94%，DSCE-CBV 成像的敏感度为 71%。当排除主要高级别肿瘤伴混合性放射性坏死为主的区域时，DSCE-CBV 的敏感度提高至 90%，但 ASL 敏感度保持不变。
与 DSCE-CBV 成像相比，ASL 成像可能更准确地区分以肿瘤复发性为主的高级别肿瘤与放射性坏死，尤其是在存在混合性放射性坏死的区域，DSCE-CBV 成像可能因漏出伪影而低估真实的血容量。
