FIG. 6.

Differentiation between recurrent tumor and radiation necrosis. Biopsy of this clinically worsening tumor, taken from the region with positive magnetic resonance contrast enhancement, evidenced only necrosis. However, a second biopsy from the area of increased amino acid uptake (arrowheads) revealed the findings of recurrent tumor. Reproduced with permission from Thiel et al. Enhanced accuracy in differential diagnosis of radiation necrosis by positron emission tomography-magnetic resonance imaging coregistration: technical case report. Neurosurgery 46:232–234. Copyright © 2000, Lippincott Williams & Wilkins. All rights reserved.¹⁵⁵