Intracerebral C6 glioma model in female hairless rats: assessment by using MRI and follow-up of irradiation.

An experimental intracerebral C6 glioma model in immunosuppressed female hairless rats has been developed. The rate of tumor uptake was evaluated by magnetic resonance imaging (MRI), using specific sequences without gadolinium enhancement. Twenty-four hours before intracerebral transplantation, a control cranial MRI was carried out and rats underwent a total body irradiation (TBI). MRI was repeated seven days after transplantation in order to monitor tumor uptake. Then, twelve days after transplantation, tumors were treated with two different protocols of radiotherapy: 3 Gy during 5 days or 0.7 Gy three times a day during 5 days (ultra fractionation). A third MRI was performed 21 days after intracerebral transplantation. Eventually, all the rats were sacrificed and histological analysis of the tumors was performed. Our results show that TBI efficiently increases the rate of tumor uptake. Thereafter, tumor formation and growth as well as the efficiency of a therapy (radiotherapy in our case) can be monitored with MRI (without gadolinium enhancement). Treatment of C6 glioma tumors with ultrafractionation was a marked improvement compared to a more traditional radiotherapy treatment. We developed a model that is useful for the study of new glioma treatment. We also obtained promising preliminary results when using ultra fractionation radiotherapy.