Baseline 11C-methionine PET reflects the natural course of grade 2 oligodendrogliomas.
OBJECTIVE
The aim of the present study was to assess the usefulness of positron emission tomography (PET) with the amino acid tracer 11C-methionine (MET) as a predictor of time to progression (TTP) in patients with supratentorial grade 2 gliomas.


METHODS
Twenty-seven patients with glioma grade 2 subjected to a baseline PET scan received no anti-tumour treatment except for a diagnostic operation, and were followed until tumour progression. The prognostic impact of the MET uptake and of other prognostic factors was studied.


RESULTS
Twenty-five of the patients (93%) experienced tumour progression after a median of 103 weeks. Low uptake of MET was a predictor for long TTP in patients with oligodendrogliomas (p = 0.04) but not in astrocytomas/oligoastrocytomas. Other predictors for long TTP were oligodendroglioma histology (p = 0.009) and seizures as presenting symptom (p = 0.03). Favourable prognostic factors for overall survival were oligodendroglioma histology (p = 0.002) and good performance status (p = 0.03).


CONCLUSIONS
PET MET has a definite role in the therapeutic management of grade 2 gliomas. However, for the optimal use of PET MET in the clinical management of these patients, histological subclassification of the tumour is required.
Department of Neuroscience, Neurology, University Hospital, SE-751 85 Uppsala, Sweden. dan.ribom@lthalland.se
Dan
D
Ribom
Anja
A
Smits
D000293:Adolescent; D000328:Adult; D000368:Aged; D001932:Brain Neoplasms / Q000145:classification / Q000000981:diagnostic imaging*; D002250:Carbon Radioisotopes; D018450:Disease Progression; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods; D008297:Male; D008715:Methionine; D008875:Middle Aged; D009836:Oligodendroglia / Q000145:classification / Q000000981:diagnostic imaging*; D049268:Positron-Emission Tomography / Q000379:methods*; D011237:Predictive Value of Tests; D012189:Retrospective Studies; D013997:Time Factors
D002250:Carbon Radioisotopes; D008715:Methionine