What is cavernous hemangioma Luschka first described cavernous hemangioma in 1854. Russell and Rubinstain named it cavernous angioma (CA) based on the pathological feature that the lesion consists of cavernous vascular cavities. It, like cerebral arteriovenous malformations, is not actually a true tumor, but is a congenital vascular lesion among cerebral vascular malformations. Cavernous hemangiomas differ from cerebral arteriovenous malformations in the lack of distinct blood-supplying arteries and draining veins, and in the lack of rapid blood flow, but there is an abundance of small blood vessels that enter the interior of the lesion. The macroscopic specimen of cavernous hemangioma was observed as a dark red round or lobulated malformed vascular mass without peritoneum, with clear borders, and within it was a honeycomb thin-walled vascular lumen, which was spongy in section. Microscopic examination shows that it consists of clumps of thin-walled vascular sinus-like structures separated by nerve fibers, but without normal nerve tissue, the vascular lumen is of unequal sizes, the wall of the vascular sinus lacks elastic lamina and muscular tissues, and there are no obvious arteries and draining veins for blood supply. It is prone to hemorrhage, thrombosis, vitreous degeneration, fibrosis and calcification, and even ossification. The diameter of cavernous hemangioma is less than 2cm, which can be repeated many times with small amount of hemorrhage, the hematoma is constantly mechanized, and the brain tissue around the tumor is reactive gliosis, so there is a tendency for the lesion to increase in size. The disease is most common in middle-aged people aged 30-40 years, with no obvious gender differences. The incidence rate in the population is about 0.5%-0.7%, accounting for 8%-15% of all cerebrovascular malformations. The lesions are mostly single, and the multiple ones account for about one quarter. Clinical manifestations Spongiform hemangioma without clinical symptoms accounts for 11%-44% of all cases. Mild headache can be the only symptom, and patients are often found when doing health checkup imaging examination. However, about 40% of asymptomatic cavernous hemangiomas flare up as a symptomatic patient after six months to two years. The main clinical manifestations of cavernous hemangioma are epilepsy, hemorrhage, neurological symptoms, and headache. (A) epilepsy: epilepsy is the most common symptom of cavernous hemangioma, about 35.8% of patients have a history of epileptic seizures, Casazza et al. statistics show that 40% of patients with cavernous hemangiomas on the curtain clinically manifested as refractory epilepsy. The incidence of epilepsy is higher in patients with lesions located in the temporal lobe, with calcifications or ferritin deposits in the surrounding brain tissue, and in male patients. Its epileptic pathogenesis is generally believed to be caused by the compression and stimulation of the surrounding brain tissue by the lesion or hemorrhage, or gliosis of the surrounding brain tissue. (ii) Hemorrhage: Significant hemorrhage occurs in about 25.4% of patients. Cavernous hemangioma can be repeated many times with small amount of hemorrhage, and almost all patients seen in the clinic have a history of hemorrhage, but due to the small blood-supplying arteries, low pressure of hematoma in the tumor body, the amount of hemorrhage is not large, resulting in a relatively small amount of hemorrhage that causes obvious clinical symptoms, which accounts for only 8-37%. The rate of hemorrhage is considerably higher in patients with lesions located in the subepithelium, in female patients, especially pregnant women, in children, and in patients with a history of previous hemorrhage. Compared with bleeding from cerebral arteriovenous malformations, hemorrhage is generally less frequent and much less dangerous, and rarely poses a threat to life except in important functional areas. Bleeding is generally well recovered by conservative treatment. (C) Neurological symptoms: 20.2% of patients have signs and symptoms of neurological damage, depending on the site and size of the CA and whether it is bleeding. Clinical symptoms are different depending on the site, if the brainstem CA, generally have limb movement disorder on the symptoms and signs, and most of them are manifested at the time of hemorrhage and after the hemorrhage. (D) Headache: 6.4% of patients have headache, which usually occurs during hemorrhage. Headache usually occurs when bleeding occurs. Because CA often occurs repeated bleeding, headache is often a paroxysmal attack. Normally, a considerable part of the patients only manifested as simple mild headache. Indications of Gamma Knife Treatment The main purpose of Gamma Knife treatment for cavernous angioma is to control seizures, reduce the size of the lesion, reduce bleeding, improve the impaired function or stop the further development of the disease. The indications for Gamma Knife treatment of cavernous hemangioma are: (1) The diameter of the lesion is <3cm. (2) There is a history of epilepsy or hemorrhage and impaired neurological function. (3)Those whose lesions are deep or located in important functional areas not suitable for surgical resection. (4) Those who are too old and weak to tolerate surgery. Fourth, the efficacy of treatment Now can not effectively to confirm the gamma knife treatment of cavernous hemangioma after the occlusion of abnormal blood vessels, the lesion shrinkage rate is not high, but from the point of view of the control of epileptic seizures is still ideal. Jean et al. reported 49 cases of cavernous hemangioma accompanied by epilepsy gamma knife treatment results, 26 cases (53%) the disappearance of epileptic seizures, 10 (20%) epilepsy improved, 13 cases (26%) no significant change in seizures. Kida et al. reported the results of Gamma Knife treatment for 11 cases of CA with refractory epilepsy, the size of the lesion was not significantly reduced, but the epilepsy was well controlled in 7 (65%) patients. In the Beijing Overseas Gamma Knife Center, of the 36 patients who received follow-up, 16 had controlled epilepsy and 7 had improved epilepsy, for an epilepsy control rate of 51%. Gamma knife treatment of cavernous hemangioma on the control of bleeding seems to have some controversy, but from the publicly reported data, gamma knife treatment of cavernous hemangioma is able to reduce the bleeding rate, Kondziolka reported 47 cases of CA before and after Gamma Knife bleeding rate statistics, the annual bleeding rate of 56.5% before treatment, the average annual bleeding rate of 8.8%, that Gamma Knife therapy cavernous hemangioma can significantly reduce the occurrence of rebleeding, especially in patients 2 years after treatment, the annual bleeding rate is only 1.1%.Hasegawa et al. counted the bleeding rate before and after Gamma Knife treatment of 82 cavernous hemangiomas, and the annual bleeding rate before treatment was 33.9%, the annual bleeding rate in 2 years after treatment was 12.3%, and after 2 years it was 0.76%, which indicates that Gamma Knife treatment can reduce the CA Bleeding rate. Beijing Overseas Gamma Knife Center reported that the annual bleeding rate after CA treatment was 2.5%, which is also considered to be able to reduce the bleeding rate. The main complications after Gamma Knife treatment are edema of brain tissue around the lesion and late radioactive damage, but the incidence of these complications has been greatly reduced after strict control of peripheral dose.