Work in progress: [18F] fluorodeoxyglucose and positron emission tomography in the evaluation of radiation necrosis of the brain.

Abstract

Five patients who had undergone radiation therapy for cerebral tumors and whose conditions were deteriorating were examined by means of positron emission tomography (PET) with [18F] fluorodeoxyglucose. All five cases had similar clinical and computed tomographic findings. Using the PET technique the two cases of radiation necrosis were distinguished from the three recurrent tumors. In the two cases of radiation necrosis the rate of glucose utilization in the lesion was markedly reduced compared with the normal brain parenchyma. In the recurrent gliomas, however, the glucose metabolic rate was elevated. All five diagnoses were confirmed by biopsy or autopsy.

Practice Based Evidence of the Beneficial Impact of PET in Patients with Brain Tumors

“…For example, when uptake within the tumor mass is greater 91.4× contralateral white matter, tumor recurrence rather than radiation necrosis is the likely diagnosis. [4]. Thus, despite its limited sensitivity for low-grade tumors, the current study demonstrates that FDG-PET has a substantial impact on intended patient management.…”

Oncological applications of positron emission tomography with fluorine-18 fluorodeoxyglucose

“…It is most often impossible to make this differential diagnosis by CT or MR/in those patients who have been operated on and then treated by radiotherapy, and present a few months later with a partially necrotic lesion and peripheral contrast enhancement. FDG PET proved useful in these cases to differentiate tumour recurrences exhibiting a high uptake of FDG from radiation necrosis in which the uptake of FDG is low [356,[365][366][367]. In this indication, FDG PET proved superior to rubidium-82 PET [367].…”

The sensitivity and specificity of FDG PET in distinguishing recurrent brain tumor from radionecrosis in patients treated with stereotactic radiosurgery

“…For PET, it is necessary to use metabolic trac-ers such as 18 F-fluorodeoxyglucose (FDG), 11 Cmethionine, or 131 I-iododeoxyuridine [5]. FDG is the most widely used tracer for studying brain lesion metabolism.…”

“…Some institutions report high accuracy [9][10][11][12][13], whereas others report that PET is neither sensitive enough nor specific enough to be used routinely [7,[14][15][16].…”