TH-C-141-05: A Simulation Study to Investigate the Potential of Using Magnetic Resonance Elastography (MRE) to Differentiate Recurrent Tumor and Radiation Necrosis

2013 ◽  
Vol 40 (6Part32) ◽  
pp. 540-540 ◽  
Author(s):  
Y Feng ◽  
P Bayly ◽  
J Huang ◽  
C Robinson ◽  
D Du ◽  
...  
Keyword(s):  
Magnetic Resonance ◽  
Simulation Study ◽  
Radiation Necrosis ◽  
Magnetic Resonance Elastography ◽  
Recurrent Tumor

CAN STANDARD MAGNETIC RESONANCE IMAGING RELIABLY DISTINGUISH RECURRENT TUMOR FROM RADIATION NECROSIS AFTER RADIOSURGERY FOR BRAIN METASTASES? A RADIOGRAPHIC-PATHOLOGICAL STUDY

Neurosurgery ◽  
2008 ◽  
Vol 63 (5) ◽  
pp. 898-904 ◽  
Author(s):  
Ivan M. Dequesada ◽  
Ronald G. Quisling ◽  
Anthony Yachnis ◽  
William A. Friedman
Keyword(s):  
Magnetic Resonance Imaging ◽  
Magnetic Resonance ◽  
Radiation Necrosis ◽  
Cyst Formation ◽  
Recurrent Tumor ◽  
Resonance Imaging ◽  
Metastatic Brain Tumors ◽  
Arteriovenous Shunting ◽  
Perilesional Edema ◽  
Standard Magnetic Resonance Imaging

Abstract OBJECTIVE Stereotactic radiosurgery is a commonly used treatment method in the management of metastatic brain tumors. When lesions enlarge after radiosurgery, it may represent tumor regrowth, radiation necrosis, or both. The purpose of this study was to determine whether standard magnetic resonance imaging (MRI) sequences could reliably distinguish between these pathological possibilities. METHODS A total of 619 patients, reported in a previous study, were treated with radiosurgery for metastatic brain tumors. Of those patients, 59 underwent subsequent craniotomy for symptomatic lesion enlargement. Of those 59 patients, 32 had complete preoperative MRI studies as well as surgical pathology reports. The following MRI features were analyzed in this subset of patients: arteriovenous shunting, gyriform lesion or edema distribution, perilesional edema, cyst formation, and pattern of enhancement. A novel radiographic feature, called the lesion quotient, which is the ratio of the nodule as seen on T2 imaging to the total enhancing area on T1 imaging, was also analyzed. RESULTS Sensitivity, specificity, and predictive values were computed for each radiographic characteristic. Lesions containing only radiation necrosis never displayed gyriform lesion/edema distribution, marginal enhancement, or solid enhancement. All lesions exhibited perilesional edema. A lesion quotient of 0.6 or greater was seen in all cases of recurrent tumor, a lesion quotient greater than 0.3 was seen in 19 of 20 cases of combination pathology, and a lesion quotient of 0.3 or less was seen in 4 of 5 cases of radiation necrosis. The lesion quotient correlated with the percentage of tumor identified on pathological specimens. CONCLUSION The lesion quotient appears to reliably identify pure radiation necrosis on standard sequence MRI. Other examined radiographic features, including arteriovenous shunting, gyriform lesion/edema distribution, enhancement pattern, and cyst formation, achieved 80% or greater predictive value but had either low sensitivity or low specificity.

Serial proton magnetic resonance spectroscopy imaging of glioblastoma multiforme after brachytherapy

1997 ◽  
Vol 87 (4) ◽  
pp. 525-534 ◽  
Author(s):  
Lawrence L. Wald ◽  
Sarah J. Nelson ◽  
Mark R. Day ◽  
Susan E. Noworolski ◽  
Roland G. Henry ◽  
...  
Keyword(s):  
Glioblastoma Multiforme ◽  
Magnetic Resonance ◽  
Proton Magnetic Resonance ◽  
Proton Magnetic Resonance Spectroscopy ◽  
Radiation Necrosis ◽  
Resonance Spectroscopy ◽  
Recurrent Tumor ◽  
Imaging Data ◽  
Content Type ◽  
Fine Print

✓ The utility of three-dimensional (3-D) proton magnetic resonance spectroscopy (1H-MRS) imaging for detecting metabolic changes after brain tumor therapy was assessed in a serial study of 58 total examinations of 12 patients with glioblastoma multiforme (GBM) who received brachytherapy. Individual proton spectra from the 3-D array of spectra encompassing the lesion showed dramatic differences in spectral patterns indicative of radiation necrosis, recurrent or residual tumor, or normal brain. The 1H-MRS imaging data demonstrated significant differences between suspected residual or recurrent tumor and contrast-enhancing radiation-induced necrosis. Regions of abnormally high choline (Cho) levels, consistent with viable tumor, were detected beyond the regions of contrast enhancement for all 12 gliomas. Changes in the serial 1H-MRS imaging data were observed, reflecting an altered metabolism following treatment. These changes included the significant reduction in Cho levels after therapy, indicating the transformation of tumor to necrotic tissue. For patients who demonstrated subsequent clinical progression, an increase in Cho levels was observed in regions that previously appeared either normal or necrotic. Several patients showed regional variations in response to brachytherapy as evaluated by 1H-MRS imaging. This study demonstrates the potential of noninvasive 3-D 1H-MRS imaging to discriminate between the formation of contrast-enhancing radiation necrosis and residual or recurrent tumor following brachytherapy. This modality may also allow better definition of tumor extent prior to brachytherapy by detecting the presence of abnormal metabolite levels in nonenhancing regions of solid tumor.

Sign in / Sign up

Export Citation Format

Share Document