[Value of 18F-FDG PET imaging in diagnosing tumor residue of intracranial glioma after surgery and radiotherapy].

ABSTRACT

BACKGROUND & OBJECTIVE: It is difficult to diagnose tumor residue by CT/MRI after treatment. The application of (18)F-fluorodeoxyglucose positron emission tomography ((18)F-FDG PET) to determine the suspected tumor residue after treatment has become a hot target in the study of radiotherapy. This study was designed to discuss the clinical value of (18)-FDG PET imaging in post-operative and post-radiotherapeutic intracranial glioma. METHODS: (18)F-FDG PET imaging was performed in 23 patients with post-operative and post-radio-therapeutic intracranial glioma, and compared with CT/MRI. The final diagnosis of tumor residue was proved by pathology or clinical follow-up. RESULTS: Of 23 patients, 12 showed (18)F-FDG PET positive, and 11 showed negative,among which 3 were false negative. The accuracy of (18)F-FDG PET was 87.0% (20/23), significantly higher than 60.9% (14/23) of CT/MRI scan (P< 0.05). The diagnosis of tumor residue in 9 patients cannot be determined by CT/MRI, while 4 of these patients showed (18)F-FDG PET positive, and the other 5 showed (18)F-FDG PET negative. Eight of 23 patients diagnosed tumor residues by CT/MRI, showed (18)F-FDG PET positive,too. Six patients,diagnosed by CT/MRI as radioactive-disease sufferers, and PET indicated with low or deficient FDG metabolism, were proved to have radioactive diseases by follow-up. CONCLUSIONS: (18)F-FDG PET imaging has significant dominance in characterizing lesions,and differentiating tumor residue in post-operative and post-radiotherapeutic intracranial glioma. Combined with CT and MRI, it can provide both anatomical and functional information for treatment.