Czernicki Tomasz, Szeszkowski Wojciech, Marchel Andrzej, Gołebiowski Marek
Department of Neurosurgery, Medical University of Warsaw, 1A Banacha Street, 02-097 Warsaw, Poland.
Folia Neuropathol. 2009;47(1):43-9.
The aim of the study was to find differences in magnetic resonance spectroscopy (MRS) which might facilitate differential diagnosis between tumour regrowth and a remnant tumour with present postradiation changes or postradiation necrosis in the vicinity of the postoperative bed, based on the assessment of the dynamics between two MRS, i.e. preoperative and postoperative scanning, performed at 6 months after surgery. Therefore, in 9 patients with high-grade gliomas, MRS spectra were obtained. Subsequently, a partial tumour resection was done in 5 patients, and 4 subjects underwent a gross total resection. On the second MRS the voxel was placed on an observed contrast enhancement area. The tumour regrowth onset was established by comparing the results of control MRI with postoperative CT scans, and also on the basis of changes in clinical condition as well as a further follow-up, including MRI studies. In patients with tumour regrowth Cho/NAA and Lac/Cr ratios increased and the NAA/Cr ratio decreased between the two MRS studies; in the patients without regrowth, the ratio changes were inverse. In both groups, a decrease in Cho/Cr ratio was observed. In a univariate analysis the presence of tumour regrowth and an increase in Cho/NAA ratio between the two MRS were correlated with a shorter further survival time; a tendency to shorter further survival time was noted with decrease in NAA/Cr ratio. In conclusion, MRS is a diagnostic tool which, on the basis of direction of changes in the value of metabolite ratios, helps additionally confirm the diagnosis of glioma regrowth. In the case of a visible contrast enhancement area on the postoperative MRI with observed concomitant increase in Cho/NAA ratio and decrease in NAA/Cr ratio between pre- and postoperative MRS examinations, preliminary suspicion should be that of glioma regrowth rather than of remnant tumour after surgery or postradiation lesions.
本研究的目的是基于对术后6个月进行的两次磁共振波谱（MRS）（即术前和术后扫描）之间动态变化的评估，找出MRS中的差异，这可能有助于鉴别肿瘤复发与术后术床附近存在放疗后改变或放疗后坏死的残留肿瘤。因此，对9例高级别胶质瘤患者进行了MRS波谱分析。随后，5例患者进行了部分肿瘤切除术，4例患者进行了全切除。在第二次MRS检查时，将体素置于观察到的对比增强区域。通过比较对照MRI与术后CT扫描结果，以及根据临床状况的变化和进一步的随访（包括MRI研究）来确定肿瘤复发的开始时间。在肿瘤复发的患者中，两次MRS研究之间Cho/NAA和Lac/Cr比值升高，NAA/Cr比值降低；在无复发的患者中，比值变化相反。在两组中，均观察到Cho/Cr比值降低。在单因素分析中，肿瘤复发的存在以及两次MRS之间Cho/NAA比值的升高与较短的进一步生存期相关；随着NAA/Cr比值降低，观察到进一步生存期缩短的趋势。总之，MRS是一种诊断工具，它基于代谢物比值变化的方向，有助于进一步确认胶质瘤复发的诊断。在术后MRI上可见对比增强区域，且术前和术后MRS检查之间观察到Cho/NAA比值升高和NAA/Cr比值降低的情况下，初步怀疑应为胶质瘤复发，而非术后残留肿瘤或放疗后病变。
