Tian K, Wang L, Ma J, Wang K, Li D, Du J, Jia G, Wu Z, Zhang J
From the Department of Neurosurgery (K.T., L.W., J.M., K.W., D.L., G.J., Z.W., J.Z.), Beijing Tiantan Hospital, Capital Medical University, Beijing, China.
China National Clinical Research Center for Neurological Diseases (K.T., L.W., J.M., K.W., D.L., G.J., Z.W., J.Z.), Beijing, China.
AJNR Am J Neuroradiol. 2017 Jun;38(6):1206-1211. doi: 10.3174/ajnr.A5152. Epub 2017 Apr 20.
Skull base chordoma has been widely studied in recent years, however, imaging characteristics of this tumor have not been well elaborated. The purpose of this study was to establish an MR imaging grading system for skull base chordoma.
In this study, 156 patients with skull base chordomas were retrospectively assessed. Tumor-to-pons signal intensity ratios were calculated from pretreatment MR images R (ratio of tumor to pons signal intensity in T1 FLAIR sequence), R (ratio of tumor to pons signal intensity in T2 sequence) and R (ratio of tumor to pons signal intensity in enhanced T1 FLAIR sequence), and significant ratios for overall survival and progression-free survival were selected to establish a grading system. Clinical variables among different MR imaging grades were then analyzed to evaluate the usefulness of the grading system.
R ( < .001) and R ( = .04) were identified as significant variables affecting progression-free survival. After analysis, the classification criteria were set as follows: MR grade I, R > 2.49 and R ≤ 0.77; MR grade II, R > 2.49 and R > 0.77, or R ≤ 2.49 and R ≤ 0.77; and MR grade III, R ≤ 2.49 and R > 0.77. MR grade III tumors had a more abundant tumor blood supply than MR grade I tumors ( < .001), and the intraoperative blood loss of MR grade III tumors was higher than that of MR grade I tumors ( = .002). Additionally, skull base chordoma progression risk increased by 2.071 times for every single MR grade increase ( < .001).
A higher R value was a negative indicator of tumor progression, whereas a higher R value was a positive risk factor of tumor progression. MR grade III tumors showed a more abundant blood supply than MR grade I tumors, and the risk of skull base chordoma progression increased with every single MR grade increase.
近年来，颅底脊索瘤已得到广泛研究，然而，该肿瘤的影像学特征尚未得到充分阐述。本研究的目的是建立一种颅底脊索瘤的磁共振成像分级系统。
本研究对156例颅底脊索瘤患者进行了回顾性评估。从治疗前的磁共振图像中计算肿瘤与脑桥的信号强度比R（T1 FLAIR序列中肿瘤与脑桥信号强度之比）、R（T2序列中肿瘤与脑桥信号强度之比）和R（增强T1 FLAIR序列中肿瘤与脑桥信号强度之比），并选择影响总生存期和无进展生存期的显著比值来建立分级系统。然后分析不同磁共振成像分级之间的临床变量，以评估该分级系统的实用性。
R（<0.001）和R（=0.04）被确定为影响无进展生存期的显著变量。经分析，分类标准设定如下：磁共振I级，R>2.49且R≤0.77；磁共振II级，R>2.49且R>0.77，或R≤2.49且R≤0.77；磁共振III级，R≤2.49且R>0.77。磁共振III级肿瘤的肿瘤血供比磁共振I级肿瘤更丰富（<0.001），且磁共振III级肿瘤的术中失血量高于磁共振I级肿瘤（=0.002）。此外，颅底脊索瘤进展风险随磁共振分级每增加一级而增加2.071倍（<0.001）。
较高的R值是肿瘤进展的负性指标，而较高的R值是肿瘤进展的正性危险因素。磁共振III级肿瘤的血供比磁共振I级肿瘤更丰富，且颅底脊索瘤进展风险随磁共振分级每增加一级而增加。
