Glioma Recurrence Versus Radiation Necrosis? A Pilot Comparison of Arterial Spin-Labeled, Dynamic Susceptibility Contrast Enhanced MRI, and FDG-PET Imaging

Ozsunar, Yelda; Mullins, Mark E.; Kwong, Kenneth; Hochberg, Fred H.; Ament, Christine; Schaefer, Pamela W.; Gonzalez, R. Gilberto; Lev, Michael H.

doi:10.1016/j.acra.2009.10.024

« Previous Next »Academic Radiology
Volume 17, Issue 3 , Pages 282-290, March 2010

Glioma Recurrence Versus Radiation Necrosis?

A Pilot Comparison of Arterial Spin-Labeled, Dynamic Susceptibility Contrast Enhanced MRI, and FDG-PET Imaging

This study was presented at the 87th Scientific Assembly and Annual Meeting of the Radiological Society of North America in 2001.

Yelda Ozsunar, MD
- Department of Radiology, Adnan Menderes University, School of Medicine, Hastane Caddesi, Aydin, Turkey
- Address correspondence to: Y.O.
Mark E. Mullins, MD, PhD
- Department of Radiology, Emory University, Atlanta, GA
Kenneth Kwong, PhD
- Department of Radiology, Massachusetts General Hospital, Boston, MA
- Harvard Medical School, Boston, MA
Fred H. Hochberg, MD
- Department of Neurology and Brain Tumor Center, Massachusetts General Hospital, Boston, MA
- Harvard Medical School, Boston, MA
Christine Ament, MD
- Boston University Eye Associates, Trygve Gunderson Eye Center, Boston, MA
Pamela W. Schaefer, MD
- Department of Radiology, Massachusetts General Hospital, Boston, MA
- Harvard Medical School, Boston, MA
R. Gilberto Gonzalez, MD, PhD
- Department of Radiology, Massachusetts General Hospital, Boston, MA
- Harvard Medical School, Boston, MA
Michael H. Lev, MD
- Department of Radiology, Massachusetts General Hospital, Boston, MA
- Harvard Medical School, Boston, MA

Received 31 August 2009; accepted 21 October 2009. published online 11 January 2010.

Rationale and Objectives

Distinguishing recurrent glial tumor from radiation necrosis can be challenging. The purpose of this pilot study was to preliminarily compare unenhanced arterial spin-labeled (ASL) imaging, dynamic susceptibility contrast-enhanced cerebral blood volume (DSCE-CBV) magnetic resonance imaging, and positron emission tomographic (PET) imaging in distinguishing predominant glioma recurrence or progression from predominant radiation necrosis in postoperative patients treated with proton-beam therapy.

Methods

Patients with grade II to IV glioma previously treated with surgery and proton-beam therapy were enrolled on the basis of new enhancing nodules or masses with primary differential diagnoses of predominant tumor recurrence or progression versus radiation necrosis. ASL, DSCE-CBV, and PET examinations were assessed by visual qualitative and quantitative analysis for the detection of predominant tumor recurrence. Imaging results were correlated with a clinical-pathologic reference standard.

Results

Thirty patients were studied, resulting in 33 ASL, 32 DSCE-CBV, and 26 PET examinations. On the basis of visual inspection, the sensitivities of PET, ASL, and DSCE-CBV examinations for detecting high-grade tumor foci were 81%, 88%, and 86%, respectively. The highest sensitivity values for quantitative ASL imaging were obtained using a normalized cutoff ratio of 1.3, resulting in sensitivity of 94% for ASL imaging and 71% for DSCE-CBV imaging. When predominant high-grade tumors with superimposed regions of predominant mixed radiation necrosis were excluded, DSCE-CBV sensitivity improved to 90%, but ASL sensitivity remained unchanged.

Conclusions

Compared with DSCE-CBV imaging, ASL imaging may more accurately distinguish predominant recurrent high-grade glioma from radiation necrosis, especially in regions with mixed radiation necrosis, for which DSCE-CBV imaging may underestimate true blood volume because of leakage artifacts.

Key Words: Arterial spin labeling, perfusion MRI, brain tumors, glioma, perfusion, radiation necrosis