Einstein (São Paulo) (Mar 2012)
Tumor growth analysis by magnetic resonance imaging of the C6 glioblastoma model with prospects for the assessment of magnetohyperthermia therapy
Abstract
Objective: The objective was to establish a pattern of tumor growthof the C6 model of glioblastoma multiform in Wistar rats via magneticresonance imaging (MRI) for the subsequent verification of tumorvolume reduction due to magnetic hyperthermia therapy. Methods:Young male Wistar rats weighing between 250 and 300 g were used for the C6 model. After the rates were anesthetized (55 mg/kg ketamine and 11 mg/kg xylazine), C6 lineage tumorigenic cells suspended in culture medium (105 cells in 10 μl) were stereotaxically injected into the right frontal cortex (bregma coordinates: 2.0 mm anteroposterior, 3.0 mm laterolateral, and 2.5 mm depth) of the ratsusing a Hamilton syringe. For the control group, the rats were injected with culture medium without cells. MRI scans were performed at 14, 21, and 28 d after the injection using a 2.0 T MRI scanner (Bruker BioSpec, Germany). The animals were anesthetized with 55 mg/kgketamine and 11 mg/kg xylazine before being examined. Coronalmultilayers were acquired using a standard spin echo sequence withthe following parameters: repetition/echo time = 4.000 ms/67.1 ms,field of view = 3.50, matrix = 192, slice thickness = 0.4 mm, andslice separation = 0 mm. Results: The MRI analysis enabled a clearvisualization of the tumor mass, and it was possible to establish thetumor volume parameters on the various days that were examined.The volume at 14 d after induction was 13.7 ± 2.5 mm3. On days21 and 28, the tumor volumes were 31.7 ± 6.5 mm3 and 122.1 ± 11.8 mm3, respectively. Conclusion: These results demonstrated that it is possible to evaluate the C6 model tumor volume in rats, which will allow for the future implementation and verification of magnetic hyperthermia therapy.
