| Budget Amount *help |
¥3,500,000 (Direct Cost: ¥3,500,000)
Fiscal Year 2006: ¥1,000,000 (Direct Cost: ¥1,000,000)
Fiscal Year 2005: ¥2,500,000 (Direct Cost: ¥2,500,000)
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| Research Abstract |
Gamma knife surgery (GKS) has been increasingly utilized to manage a wide variety of indications including arteriovenous malformations, brain tumors, Parkinson disease, or focal epilepsy. Although in clinical practice, GKS is thought to be a safe and effective treatment for these diseases, little is understood about the alteration of biological properties induced by gamma irradiation. In recent studies using animals, it has been shown that high-dose gamma irradiation causes marked degeneration of the capillary endothelial cells, consequently inducing edema and necrosis in the irradiated area. Displacement of the irradiation sites in the anteromedical direction increased spontaneous activity, and posterolateral shift provoked circling behavior on the apomorphin test. The observation of rat sciatic nerve irradiated by 100 Gy indicated that the gamma irradiation might not affect the sensitivity of the normal nerve, but does affect the release of inflammatory mediators or the activity of endogenous inhibitors.
More recently, GKS has also been employed to treat intractable pain, such as trigeminal neuralgia, thalamic pain and cancer pain. For the treatment of trigeminal neuralgia, the retro gasserian was targeted and irradiated using a 4mm collimator to deliver 90 Gy. All patients experienced a significant pain reduction within 6 months. Thus, it is very important to conduct further basic experiments to determine the optimal treatment protocol using GKS for various diseases across many fields.
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