Alternative pharmacologic therapy for aggressive central giant cell granuloma: denosumab.

In the search for new pharmacologic therapies for central giant cell granuloma (CGCG), proteins that are essential to osteoclastogenesis are intriguing potential targets. In the present case report, we describe a 25-year-old patient with an aggressive CGCG of the maxilla, who was successfully treated with the antiresorptive agent denosumab, after other pharmacologic treatment had failed to achieve regression or stabilization of the tumor. Denosumab could be a promising alternative to potentially mutilating surgery for CGCG. However, more research is needed before definite conclusions can be drawn about the potential role of this agent in the treatment of CGCG.

Experimental iodine-125 seed irradiation of intracerebral brain tumors in nude mice.

BACKGROUND: High-dose radiotherapy is standard treatment for patients with brain cancer. However, in preclinical research external beam radiotherapy is limited to heterotopic murine models- high-dose radiotherapy to the murine head is fatal due to radiation toxicity. Therefore, we developed a stereotactic brachytherapy mouse model for high-dose focal irradiation of experimental intracerebral (orthotopic) brain tumors. METHODS: Twenty-one nude mice received a hollow guide-screw implanted in the skull. After three weeks, 5 x 105 U251-NG2 human glioblastoma cells were injected. Five days later, a 2 mCi iodine-125 brachytherapy seed was inserted through the guide-screw in 11 randomly selected mice; 10 mice received a sham seed. Mice were euthanized when severe neurological or physical symptoms occurred. The cumulative irradiation dose 5 mm below the active iodine-125 seeds was 23.0 Gy after 13 weeks (BEDtumor = 30.6 Gy). RESULTS: In the sham group, 9/10 animals (90%) showed signs of lethal tumor progression within 6 weeks. In the experimental group, 2/11 mice (18%) died of tumor progression within 13 weeks. Acute side effects in terms of weight loss or neurological symptoms were not observed in the irradiated animals. CONCLUSION: The intracerebral implantation of an iodine-125 brachytherapy seed through a stereotactic guide-screw in the skull of mice with implanted brain tumors resulted in a significantly prolonged survival, caused by high-dose irradiation of the brain tumor that is biologically comparable to high-dose fractionated radiotherapy- without fatal irradiation toxicity. This is an excellent mouse model for testing orthotopic brain tumor therapies in combination with radiation therapy.