Morphological and dynamic contrast enhanced MR imaging features for the differentiation of chordoma and giant cell tumors in the Axial Skeleton

Abstract

Purpose: To characterize the morphological and dynamic-contrast-enhanced (DCE) MRI features of chordoma and giant cell tumor (GCT) of bone occurring in the axial skeleton. Materials and Methods: A total of 13 patients with chordoma and 26 patients with GCT who received conventional T1, T2, and DCE-MRI on 3 Tesla MR scanners were retrospectively identified and analyzed. Two radiologists evaluated morphological features independently, including the lesion location, expansile bone changes, vertebral compression, presence of paraspinal soft tissue mass, fibrous septa, and the signal intensity on T1WI and T2WI. The inter-observer agreement was evaluated by kappa test. The DCE kinetics was measured to obtain the initial area under curve (IAUC) and the wash-out slope; also the two-compartmental pharmacokinetic model was applied to obtain Ktrans and kep. The diagnostic accuracy was evaluated by CHAID decision tree and ROC analysis. Results: Chordomas were more likely to show soft tissue mass than GCTs (13/13 = 100% versus 15/26 = 58%; P = 0.007), as well as fibrous septa (9/13 = 69% versus 0; P<0.001). In decision tree analysis, presence of fibrous septa and lesion location yield 31/39 = 79% accuracy. The DCE-MRI pharmacokinetic parameters Ktrans and kep of GCTs were significantly higher than those of chordomas, 0.136 0.65 versus 0.0660.04 (1/min) for Ktrans, 0.6260.22 versus 0.176 0.12 (1/min) for kep, P<0.001 for both. If using kep = 0.43/min as the cut-off value, it achieved 100% sensitivity and 92% specificity to differentiate chordoma from GCT, with an overall accuracy of 37/39 = 95%. The IAUC was highly correlated with Ktrans (r = 0.94), and the slope was highly correlated with kep (r = 0.95). Conclusion: Several morphological features were significantly different between chordoma and GCT, but their diagnostic performance was inferior to that of DCE-MRI.

MRI biomarkers in osseous tumors

“…A recent study looked for any additional value of pharmacokinetic parameters for differentiating chordoma from GCT in the axial skeleton. 83 Although combined morphological features achieved good diagnostic performance, they found significantly higher values of K trans and K ep in GCT than in chordoma. The authors assumed that microscopic observations of GCT such as high microvessel density with irregular lumen, thin lumen wall, and loss of endothelial cells in some vessel walls could indicate a tumor with leaky vessels.…”

“…A recent study looked for any additional value of pharmacokinetic parameters for differentiating chordoma from GCT in the axial skeleton . Although combined morphological features achieved good diagnostic performance, they found significantly higher values of K trans and K ep in GCT than in chordoma.…”

Differential Diagnosis of Spine Tumors: My Favorite Mistake

“…69 DCE is probably one of the most investigated MR tools for the evaluation of SBTs and a source of several ongoing studies, although it was already demonstrated to be a robust and reliable method. For instance, it was proven to be helpful to discriminate different SBTs, 70,71 as well as to distinguish SBTs from infectious conditions, 72,73 and promising results were also described in the evaluation of the response to therapy. 74 Regarding spine infection, morphological features remain crucial diagnostic findings to correctly differentiate it from SBT, with, for instance, absence of disk involvement, with a paravertebral or epidural abscess typical for the latter.…”

T1-Weighted Dynamic Contrast-Enhanced MR Perfusion Imaging Characterizes Tumor Response to Radiation Therapy in Chordoma

“…Previous studies have shown that DCE-MRI is useful for monitoring response to therapy in spinal bone metastases (13), and for discriminating between the hypo- and hyper- vascular spinal lesions of prostate carcinoma and renal cell carcinoma, respectively (14). More recently, DCE-MRI has shown clinical utility in chordoma diagnosis, effectively discriminating between chordoma and giant cell tumors of the axial skeleton (15). …”