Clinical Value of Pet with ¹⁸F-Fluorodeoxyglucose and L-Methyl-¹¹C-Methionine for Diagnosis of Recurrent Brain Tumor and Radiation Injury

Abstract

We studied 15patients clinically suspected to have recurrent brain tumor or radiation injury, using positron emission tomography (PET) with lsF-fluorodeoxyglucose eSFDG) and Lrncthyl-l'Ornethionine (llC-Met). PET with llC-Met (Met-PET) clearly delineated the extent of recurrent brain tumor as focal areas of increased accumulation of llC-Met, and was useful for early detection of recurrent brain tumor. PET with lsFDG (PDG-PET) showed focal lsFDG-hypermetabolism in one patient with malignant transformation of low grade glioma, and demonstrated its usefulness for evaluation of malignant transformation. lsFDG-hypometabolism was observed in all patients with radiation injury, but was also found in one patient with recurrent malignant brain tumor. llC-Met uptake in 3 patients with radiation injury was similar to that of the normal cortical tissue. FDG-PET can be used to initially exclude recurrent brain tumor which is seen as 18pDG-hypermetabolism. The combined use of Met-PET in addition to FDG-PET can improve the accuracy of differentiation of recurrent brain tumor with lsFDG_ hypometabolism from radiation injury.

Oncological applications of positron emission tomography with fluorine-18 fluorodeoxyglucose

“…In a few studies performed with MET, this tracer also proved useful in detecting biologically active residual or recurrent brain tumours, and could yield less false-negative results than FDG PET [369,373,374]. In our experience, MET proved much better than FDG in delineating tumour recurrences, and usually clearly depicted low-grade lesions and some high-grade lesions that were not seen with FDG [354],…”

“…Some false-negative FDG cases have been demonstrated, however, especially in recurrences of low-grade gliomas but also in histologically proven recurrences of high-grade gliomas. Some false-positive cases have also been demonstrated [361,[368][369][370][371]. Falsenegative cases may especially correspond to small lesions included in the cortex, or to partially cystic or necrotic lesions.…”

Klinische Relevanz von PET-Untersuchungen in der Neurologie und Psychiatrie

“…Die Bestimmung des Glukosestoffwechsels mit 18 Gliomen bereits in den ersten Wochen nach Operation [14,15,50].…”

“…der Aminosäureinkorporation mit markierten Aminosäu-ren, wie C-11-Methionin oder 18 F-Fluor-Ethyltyrosin, ermöglicht einen höheren Tumor/Nontumor-Kontrast als die Darstellung des Glukosestoffwechsels mit FDG [14,50,59,60] (Abbildung 6). Mit diesen markierten Aminosäuren ist eine deutlich genauere Bestimmung der Ausdehnung vitaler Tumoranteile möglich als mit FDG, der MRT oder mit Vitalitätsmarkern für die Single-Photon-Emissionstomographie (SPECT) wie Tl-201 und Tc-99m-MIBI [46,59].…”

Differential Diagnosis Between Radiation Necrosis and Glioma Progression Using Sequential Proton Magnetic Resonance Spectroscopy and Methionine Positron Emission Tomography

“…2,11,17,25,26,30) This progress has provided longer survival time for the patients after the initial treatment, but has also given rise to other problems such as differentiation of radiation necrosis from recurrent tumor. 10,21) The salvage methodology has not been established, so advances in post-initial treatment may further improve outcome. Several neuroimaging modalities have been assessed for the differential diagnosis of radiation necrosis and tumor recurrence.…”