AIM: To evaluate the proliferation activity in gliomas using 18F-fluorothymidine (18F-FLT)-positron emission tomography/computed tomography (PET/CT). PATIENTS AND METHODS: Samples of 26 tumors were analyzed (mean age=51.6; range=26-72 years; 16 males, 10 females). All examinations were performed using a PET/CT scanner equipped with lutetium oxyorthosilicate (LSO) detectors. All data were acquired with a delay of 15 min, following intravenous application of 18F-FLT (dosed 2 MBq/kg of body weight). The PET/CT contained CT after intravenous application of iodinated contrast agent and high-resolution brain PET acquired during 15 min in one position. PET/CT was performed before confirmation of the histological diagnosis and the level of 18F-FLT accumulation was compared to the grading of the tumor evaluated using immunohistochemistry staining of Ki-67. Samples were obtained by stereotactic biopsy (5×) or surgical resection (21×). RESULTS: Five tumors of grade IV, 7 tumors of grade III and 14 tumors of grade II were found. Pre-bioptical discrimination between high-grade and low-grade tumors reached accuracy 92.3% (24/26), sensitivity 92.3% (12/13) and specificity 92.9 (13/14). The mean maximum standardized uptake value (SUVmax) in high-grade tumors was 2.23, significantly different from low-grade tumors (mean SUVmax 0.61, T=7.803, p<0.0001). CONCLUSION: 18F-FLT-PET/CT enables to estimate the proliferation activity of glioma before biopsy.

Clinic of Imaging Methods University Hospital Plzen Plzeň Czech Republic

Department of Neurosurgery University Hospital Plzen Plzeň Czech Republic

Immunoanalytic Laboratory University Hospital Plzen Plzeň Czech Republic

Sikl's Institute of Pathological Anatomy University Hospital Plzen Plzeň Czech Republic

The relationship between gadolinium enhancement and [18 F]fluorothymidine uptake in brain lesions with the use of hybrid PET/MRI