Synopsis
Perfusion made it possible to obtain measurements of vascularity
within brain lesions. The vascularity of malignant tumor differs dramatically
from that of radiation necrosis. Thus, tumor recurrence within irradiated
lesions may be differentiated from regions of radiation necrosis with perfusion. 64 patients
were prospectively entered into the study on the basis of the following criteria:
previous treatment with radiation therapy after surgical resection for
intraaxial tumors; new development of enhancing lesions within the radiation
field. To compare 3D-ASL with DSC and to see whether 3D ASL-derived
CBF values can be used as an alternative to DSC for their differentiation.purpose
The differentiation of progressive or recurrent brain tumor from radiation
injury after radiotherapy is difficult using conventional MR imagings(MRI) [1].
Accurate diagnosis of tumor recurrent or radiation injury is critical to
determining therapy [2]. Perfusion, Diffusion-Weighted imaging(PWI, DWI), which
has made it possible to obtain measurements of ADC, rCBV, may be useful in
differentiation of tumor recurrence within irradiated lesions and radiation
necrosis [3]. The study was performed to
validate the value of 3D arterial spin
labeling (3D ASL), compared with dynamic susceptibility contrast (DSC)
perfusion magnetic resonance imaging (MRI), in distinguishing radiation-induced
brain necrosis from glioma recurrence in
patients with diagnosed glioblastoma multiforme (GBM) with an aim to see
whether 3D arterial spin labeling (3D ASL) can be used as an alternative to
DSC-MRI for the distinguishing.
Methods
The
MR examinations were performed on a 3.0 Tesla scanner (Discovery MR 750, GE
Healthcare, Waukesha, Wisconsin) at the Chinese PLA General Hospital. Patients
with previously resected and irradiated glioma, presenting newly developed
abnormal enhancement, were included in the study. Sixty-four patients who
developed contrast-enhancing lesions were assessed by both 3D ASL and DSC
perfusion MRI and classified into groups of
radiation-induced brain necrosis (n.32) or tumor recurrence (n.32) based
on pathologic analysis or clinical–radiologic follow-up. The DSC indices (rCBV,
rCBF, rMTT, rTTP) and 3D ASL (absolute CBF and rCBF) values were quantified from the ROI region.
Student independent t test was used to compare 3D ASL and DSC-MRI indices.
Pearson correlation was used to see correlation between DSC- and 3D ASL-derived
CBF values in contrast-enhancing lesions and edema region.
Results
On Student t test, Both 3D
ASL-derived absolute CBF (p < 0.001) and rCBF (p < 0.001) values were found to be
significantly different in 2 groups, whereas DSC indices rCBV (p < 0.001)
and rCBF (p < 0.001) have the same results.
The absolute CBF, rCBF, rCBV, and rCBF were significantly higher in
tumor recurrence groups(mean absolute CBF± SD= 59.57 ± 32.06; mean rCBF± SD=
2.64 ± 1.77; mean rCBV± SD= 3.33 ± 2.16; mean rCBF± SD= 3.31 ± 1.95) than in
radiation-induced brain necrosis groups(mean absolute CBF± SD= 28.19 ± 15.62;
mean rCBF± SD= 1.06 ± 0.49; mean rCBV± SD= 1.45 ± 1.21; mean rCBF± SD= 1.35 ±
0.76). 3D ASL-derived absolute CBF and
rCBF values stronger correlated
with DSC-derived rCBV and rCBF values.
Conclusion
Three-dimensional arterail spin labeling appear to be a reliable
technique in current form and may be a suitable replacement for DSC in
differentiating radiation-induced brain necrosis from glioma recurrence
Acknowledgements
No acknowledgement found.References
[1] Bhaswati Roy, Rishi Awasthi, Amit Bindal, et al. Comparative
Evaluation of 3-Dimensional Pseudocontinuous Arterial Spin Labeling With
Dynamic Contrast-Enhanced Perfusion Magnetic Resonance Imaging in Grading of
Human Glioma. J Comput Assist Tomogr,
2013, 37: 321-326.
[2] Young Jun Choi, Ho Sung Kim, Geon-Ho Jahng, et al. Pseudoprogression in
patients with glioblastoma: added value of arterial spin labeling to dynamic susceptibility
contrast perfusion MR imaging Acta
Radiol, 2013, 54: 448-454.
[3] Yamashita K, Yoshiura T, Hiwatashi A, et al. Differentiating
primary CNS lymphoma from glioblastoma multiforme: assessment using arterial
spin labeling, diffusion-weighted imaging, and 18F-fluorodeoxyglucose positron emission tomography Neuroradiology,
2013, 55: 135-143.